Morten Tryland

• Holmen, Mariel Wictoria; León, Arturo Vera-Ponce de; Våge, Dag Inge; Berg, Peer; Tryland, Morten & Nymo, Ingebjørg Helena [Show all 9 contributors for this article] (2026). Genomic diversity and population structure of semi-domesticated reindeer populations in southern Norway and wild reindeer from Iceland. Journal of Heredity. ISSN 0022-1503. doi: 10.1093/jhered/esag078. Full text in Research Archive Show summary

  Abstract Reindeer and caribou (Rangifer tarandus) play key ecological, cultural, and economical roles across Arctic and Subarctic regions. However, genome-wide patterns of genetic diversity and population structure in semi-domesticated reindeer from Norway remain insufficiently characterized. Here we generated a high-quality chromosome-level genome assembly (GCA_965153185.1) for Norwegian semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus). The genome spans 2.54 Gb, with a scaffold N50 of 75.6 Mb, 96.1% complete Benchmarking Universal Single-Copy Orthologues, and 39,855 predicted protein-coding genes. Using this reference, we performed whole-genome resequencing of 175 individuals from five reindeer populations from Norway and 28 individuals from Iceland, identifying ~19.9 million genetic variants. Genetic differentiation was low among Norwegian populations (FST = 0.005 to 0.011), but substantially higher between Norway and Iceland (FST = 0.140 to 0.161). Populations from Norway exhibited similar levels of nucleotide diversity (π = 1.39 to 1.62 × 10−3), whereas the Icelandic population showed reduced diversity (π = 0.99 × 10−3) and approximately half as many segregating variants. Analyses of runs of homozygosity (ROH) and genome-wide heterozygosity indicated low levels of recent inbreeding across all populations, with long ROHs (>8 Mb) being rare. Despite reduced genetic diversity, the Icelandic population showed limited evidence of recent inbreeding. These patterns are consistent with contrasting demographic histories, with gene flow maintaining diversity among populations from Norway, while founder effects combined with long-term isolation have shaped the Icelandic population.

• Aurbakken, Stine Emilie Bull; Malmström, Anna Ester Emilia; Baron, Jerome; Romano, Javier Sanchez; Philippot, Karin Wallin & Rautiainen, Heidi [Show all 9 contributors for this article] (2026). Reindeer health and supplementary feeding practices - a survey among herders in Norway and Sweden. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 68(1). doi: 10.1186/s13028-026-00868-3. Full text in Research Archive Show summary

  Background The well-being, health and nutrition of reindeer (Rangifer tarandus tarandus) and the practice of reindeer husbandry in Fennoscandia are strongly affected by climate change and the loss and fragmentation of pastures. Supplementary feeding has become increasingly common to cope with limited pasture availability, especially to avoid starvation during winters with ice-locked pastures and challenging snow conditions. Increased reliance on feeding shifts traditional reindeer husbandry towards a more farm-like system and raises concerns about changes in reindeer foraging behaviour, increased stress and disease transmission. In this study, a questionnaire was conducted among reindeer herders in Norway and Sweden, to review the extent of supplementary feeding and to explore links between feeding strategies and observations of disease in reindeer. The study also evaluated factors affecting access to and use of veterinary services. Results A total of 76 respondents, 33 from Norway and 43 from Sweden, participated. Most (87%) had applied supplementary feeding between 2015 and 2021, mainly on free-range pasture, although we observed a non-significant increasing trend in feeding in enclosures during this period. Detailed analysis of the challenging winter of 2019–2020 showed that it was most common to feed a combination of roughage (hay or silage) and pellets, and feeding typically lasted longer than one month. The most frequently reported health issues included parasites, diarrhoea, abortion, and wet belly. Reports of diarrhoea, wet belly, and necrobacillosis were significantly more common in Sweden than in Norway. Multiple correspondence analysis and hierarchical clustering analysis demonstrated an association between feeding in enclosures and diarrhoea. Veterinary services were used by 34% of the respondents for necropsies and 55% for clinical disease management, although many noted barriers such as cost and limited veterinary knowledge and expertise in reindeer health. Conclusions Supplementary feeding is widespread in reindeer husbandry in Norway and Sweden. Feeding in enclosures was associated with a higher incidence of diarrhoea. Continued competence building for good management decisions and veterinary services is essential for sustainable reindeer husbandry. An integrated One Health approach is key for the promotion of reindeer health and welfare and in preparedness for transmissible diseases among reindeer, domestic livestock and wildlife.

• Skjerdal, Olaug Taran; Bukhvalova, Barbara Alexandra; Aspholm, Marina; Grahek-Ogden, Danica; Møretrø, Trond & Myrmel, Mette [Show all 11 contributors for this article] (2026). Shelf-Life and Food Safety of Eggs in Norway. VKM Report. 2026(1), p. 1–47. doi: https:/vkm.no/download/18.7786fe319c042ac195e8a6/1769760904440/Rapport%20konsumegg.pdf. Full text in Research Archive Show summary

  The European Food Safety Authority (EFSA) assessed the shelf life of table eggs in 2014, and EU legislation currently sets a maximum shelf life of 28 days. The Norwegian Food Safety Authority asked VKM to assess shelf life under Norwegian conditions to determine whether a longer shelf life may be permitted for Norwegian eggs. VKM concluded that, because Salmonella Enteritidis is not relevant in Norwegian production chain and Norwegian temperature control significantly reduces microbial risk, the scientific basis for EFSA’s 28 day limit does not apply to Norway. A 35-day shelf life remains safe and justified, provided the cold chain is maintained.

• Frøvoll, Tuva Løken; Lybeck, Kari Røste; Lund, Hege; Makvandi-Nejad, Shokouh; Grimholt, Unni & Neves, Carlos Goncalo Rolhas Fernandes Das [Show all 9 contributors for this article] (2025). Measuring cytokines in Eurasian tundra reindeer (Rangifer tarandus tarandus) with a bovine bead-based multiplex immunoassay and real-time PCR | Acta Veterinaria Scandinavica. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 67. doi: 10.1186/s13028-025-00819-4. Full text in Research Archive Show summary

  Reindeer (Rangifer tarandus tarandus) herding is based on access to seasonal pastures. Pastureland is, however, being lost and fragmented due to e.g. climate change, human activities, and predators, creating an increasing need for feeding and fencing. This alters disease occurrence, leading to a greater need for disease investigation tools. Knowledge of the activation of immune pathways during disease can be obtained by measuring cytokines, but no commercial methods are currently available for reindeer. This study investigated whether the MILLIPLEX® Bovine Cytokine Magnetic Bead assay could be used to detect interleukin (IL)-6, IL-8, IL-10, IL-17, tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) in reindeer cell supernatants and serum. Peripheral blood mononuclear cells (PBMCs) from reindeer (n = 4) and cattle (Bos taurus, n = 3) were stimulated with mitogens for 6 and 24 h (h) and the quantity of cytokines in cell supernatants was measured. Serum from experimental viral infections in reindeer (Orf virus; ORFV and Varicellovirus cervidalpha2; CvHV2) was also analysed. Additionally, primers were designed to measure cytokine gene expression in response to mitogens by real-time polymerase chain reaction (qPCR). The bovine bead-based multiplex immunoassay detected five of six cytokines (IL-8, IL-10, IL-17, TNF-α, IFN-γ) in reindeer PBMC supernatants after stimulation. All cytokines were detected in bovine samples. Although cytokine concentrations were generally higher in bovine samples, analysis of reindeer supernatants demonstrated significantly increased IL-10, IL-17, TNF-α and IFN-γ concentrations in supernatants from stimulated compared to unstimulated PBMCs. Neither reindeer nor cattle samples showed a significant increase for IL-6, while IL-8 was increased only in bovine samples after 6 h stimulation. Serum from reindeer infected with CvHV2 showed significantly increased IFN-γ levels on days 4 and 7 post inoculation. Gene expression of all cytokines was increased by stimulation of reindeer PBMCs, except IL-6 for which primer design was unsuccessful. This study shows the potential of the bovine bead-based multiplex immunoassay for measuring IL-10, IL-17, TNF-α, and IFN-γ concentrations in reindeer. The qPCR is suitable for measuring gene expression of these cytokines and IL-8. These methods may be used to characterise immune responses in reindeer, but further testing and validation are warranted.

• Nymo, Ingebjørg Helena; Bøe, Cathrine Arnason; Romano, Javier Sanchez; Lian, Hans Edvin; Thorvaldsen, Renate & Suhel, Faisal [Show all 18 contributors for this article] (2025). First detection of a cervidpoxvirus in Europe—disease occurrence in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Norway and Sweden. Microbiology spectrum. 13(7). doi: 10.1128/spectrum.02296-24. Full text in Research Archive Show summary

  ABSTRACT Globally, there are six millions of Rangifer spp., including both wild and semi-domesticated populations. Reindeer herding with Eurasian tundra reindeer ( Rangifer tarandus tarandus ) is central to the Fennoscandian Sámi people. Commencing in 2018, a novel disease presenting with periorbital lesions was reported in reindeer in multiple locations in Norway and Sweden, as individual cases and outbreaks. Lesions were also seen on the genitals, nostrils, and ears of affected reindeer, in combination with lethargy. Necropsy findings included lesions with crusts on the eyelids, vulva, and anus, along with moderately swollen lymph nodes, liver, and spleen. Histological examination of the eyelid lesions showed a disrupted epidermis with necrotic squamous epithelium and inflammation. Shotgun sequencing of samples from outbreaks yielded a partial draft genome of a virus related to Deerpox virus W-848-83 (currently known as Cervidpoxvirus muledeerpox ) in genus Cervidpoxvirus . Cervidpoxviruses have previously only been detected in Capreolinae in North America. An in-house qPCR targeting the cervidpoxvirus virion core protein gene was designed and showed the presence of viral-specific DNA in multiple organs, with the highest load in skin lesions. RNAscope in situ hybridization detected viral transcripts in the epithelium of the eye lesions. Transmission electron microscopy analysis revealed the presence of intracytoplasmic poxvirus-like particles with characteristic morphology within the lesions. In vitro infection in Madin-Darby bovine kidney epithelial cells demonstrated cytopathic effect. It is unknown whether the emergence of this disease in semi-domesticated reindeer in Norway and Sweden is due to ecosystem changes facilitating altered disease dynamics, or if the virus has been recently introduced. IMPORTANCE This study documents the first detection of a Cervidpoxvirus in Europe, causing disease in semi-domesticated reindeer in Norway and Sweden. It identifies the causative agent and describes the disease characteristics of this previously unknown condition in reindeer, advancing our understanding of how this virus impacts reindeer health and welfare. Given the cultural and ecological importance of reindeer herding in Fennoscandia, understanding this disease is crucial for safeguarding the livelihoods of Sámi communities. Additionally, the study raises important questions about the role of ecosystem changes, climate-driven insect dynamics, and potential reservoir hosts in facilitating disease outbreaks. These findings underscore the broader implications of environmental change on animal health and highlight the need for continued research to mitigate risks posed by emerging infectious diseases (EIDs).

• Tryland, Morten & Buhler, Kayla Joy (2025). Zoonotic infections in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Fennoscandia – a review. One Health Outlook. 7(18). doi: 10.1186/s42522-025-00140-0. Full text in Research Archive Show summary

  Abstract Eurasian tundra reindeer ( Rangifer tarandus tarandus ) make up the basis for reindeer herding in Norway, Sweden and Finland, hosting about 640 000 animals. The animals are mostly free-ranging, with the exception of a few seasonal gatherings. Loss and fragmentation of pastures due to other types of land use, together with climate change and even conservation of predators, are challenging reindeer herding, leading to recent mitigations such as increased feeding. Whereas the average Norwegian consumes about 300 gr/person/year of reindeer meat, Sweden about 100 gr/person/year and Finland about 400 gr/person/year, reindeer meat and products constitutes a much larger part of the diet to members of herding communities. Preparing reindeer meat with no thorough heat treatment (e.g., drying, smoking, curing or raw consumption) can be found in many arctic and sub-arctic people’s cultures, and interest for reindeer meat that is not heat-treated has also grown (e.g., carpaccio-style), which can dramatically impact pathogen transmission. There is a wide range of zoonotic parasites, bacteria and viruses that potentially can be transferred from reindeer to human, but it can be concluded that the zoonotic threat from close contact with reindeer or the consumption of reindeer meat and products thereof currently is of restricted magnitude. However, due to the challenges that reindeer populations are facing and the mitigation by increased feeding, the infection biology of zoonotic infections may change and we may face emerging diseases (i.e., pathogens new to the host and region), such as the recently appearing prion disease, Chronic wasting disease (CWD), and re-emerging diseases, such as the alimentary form of necrobacillosis.

• Malmström, Anna Ester Emilia; Tryland, Morten; Passler, Thomas; Becker, Alice; Aurbakken, Stine Emilie Bull & Silvis, Scott [Show all 8 contributors for this article] (2025). Ear tissue as a diagnostic sample for pestivirus detection in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Norway. Frontiers in Microbiology. 16. doi: 10.3389/fmicb.2025.1688206. Full text in Research Archive Show summary

  Introduction Although eradication programs have successfully controlled pestivirus infections in domestic livestock across Fennoscandia, serological evidence suggests that several free-ranging, semi-domesticated reindeer herds are exposed to and possibly endemically infected with pestivirus(es). While the significant economic impact of pestiviruses on domestic animals is well documented, their effects on reindeer remain poorly understood. Attempts to isolate and characterize these pestiviruses from seropositive reindeer herds have so far been unsuccessful, despite analyses of serum and nasal swab samples by multiple studies. Ear tissue is commonly used to detect cattle persistently infected (PI) with pestivirus and utilized for both screening and controlling infection. Despite its practicality in cattle, ear tissue has not been utilized for the demonstration of pestivirus in reindeer. The current study aimed to examine ear tissue as sample material for the detection and isolation of pestivirus in Norwegian semi-domesticated reindeer herds. Methods Ear tissue from 3,453 reindeer calves from three geographically distinct locations were assessed by conventional reverse transcriptase polymerase chain reaction (RT-PCR), antigen capture ELISA (ACE), and virus isolation. Results A total of 24 (0.7%) individual ear tissue samples were considered potentially positive by RT-PCR but were negative by ACE, and no virus could be isolated from any of the samples. Three commercially available reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays for the diagnosis of bovine viral diarrhea virus (BVDV) were also employed from which a CT-value of less than 40 was detected in only one sample (CT 36.95). Discussion While potential positive ear tissue samples were observed in this study, it is unknown if low viral load, pestivirus genetic diversity, or sample suitability contributed to the inability to confirm pestivirus-specific RNA nor viable virus particles in the samples. The impact of pestivirus infections on health and welfare of reindeer and effect on eradication programs in Fennoscandian livestock remain undetermined and the results from this study emphasize the critical need for multidisciplinary research regarding this topic.

• Davidson, Rebecca K.; Dembereldagva, Selengemurun; Nymo, Ingebjørg Helena; Mørk, Torill; Romano, Javier Sanchez & þórarinsdóttir, R. [Show all 9 contributors for this article] (2025). An update on gastrointestinal nematodes in reindeer (Rangifer tarandus tarandus) in Iceland. International Journal for Parasitology: Parasites and Wildlife. 28. doi: 10.1016/j.ijppaw.2025.101163. Full text in Research Archive Show summary

  Eurasian tundra reindeer (Rangifer tarandus) were introduced to Iceland from Norway in the late 18th century and have thrived in Eastern Iceland. In 2003–2005 the parasitic fauna was studied, and Icelandic reindeer were found to lack many parasites common to Norwegian reindeer. This study from 2018 provides an updated comparison. Abomasal content and faeces were collected from the 117 reindeer (63 adults, 22 yearlings, 17 calves, 15 age not recorded), from: 1 - West (N = 29), 2 - Central (N = 44), 3–9 - East (N = 40), not recorded (N = 4) management areas hunted in 2018. Not all animals were examined by all methods. Abomasal nematode counts (N = 81) were carried out in addition to faecal egg and larval counts, using modified McMaster (N = 111) and Baermann (N = 108). Abomasal nematodes were detected in 31 % of samples, with low mean abundance (48) and intensity (160). Males had higher prevalence (46 %) and mean abundance (89) than females (24 %; 29). The sheep gastrointestinal nematode (GIN) Teladorsagia circumcincta predominated, although, for the first time, single specimens of Spiculopteragia boehmi (Gebauer,1932) and a male nematode with morphology suggestive of Ostertagia arctica, a minor morph of O. gruehneri, were detected. Trichostrongylus axei was not detected. Trichostrongylidae and Aonchotheca egg prevalence was 35 % (mean abundance eggs per gram, EPG, 12, mean intensity 33 EPG) and 23 % (mean abundance 8 EPG; mean intensity 34 EPG) respectively. No faecal larvae were detected. There were geographic as well as sex related differences in abundance. Trichostrongylidae eggs prevalence, but not abundance, was higher in 2018 compared to 2005, and an opposite trend with abomasal nematode counts was seen. Reindeer in Iceland still have a low prevalence and abundance of GINs, dominated by T. circumcincta. The monitoring of GIN in this population provides a simple means of evaluating population health in a time with changing climate.

• Skjerve, Eystein; Granquist, Erik Georg; Johansen, Tone Kristin Bjordal; Olsen, Ingrid; Nesbakken, Truls & Sayyari, Amin [Show all 16 contributors for this article] (2025). Risk assessment of bovine tuberculosis introduction and establishment in Norway. Scientific Opinion of the Panel on Animal Health and Welfare of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2025(04), p. 1–87. Full text in Research Archive Show summary

  Following the verification of bovine tuberculosis (bTB) after an outbreak in 2022, concerns were raised about the true epidemiological situation of bTB in Norway. Consequently, the Norwegian Food Safety Authority commissioned VKM to assess the risk of introducing Mycobacterium bovis to Norway, and the risk of its spread and establishment in Norwegian livestock and wild fauna. VKM was also tasked with assessing the risk of infection to humans and identifying risk-reducing measures and diagnostic options for detecting infection in Norway. Background: bTB is a bacterial disease affecting animals and humans, caused by M. bovis. The prevalence varies greatly across European countries. Norway has held an official free status since 1963, with only a few cases reported in the 1980s. The 2022 outbreak was identified through routine meat inspection, revealing several infected animals in a specific herd. The source of this outbreak remains unidentified, and no infected animals have been detected since early 2023. Contact network tracing linked many farms to the index (outbreak) herd through cattle trade. The identified contact herds are still monitored for infection, and the possibility of a spread to other farm animals or wildlife cannot be excluded. Norway maintains strict regulations on live animal imports and monitors the presence of bTB through mandatory reporting, meat inspections, and breeding station testing. M. bovis can infect a wide variety of domestic and wildlife species. Furthermore, there is a significant public health concern due to its zoonotic potential. bTB is a chronic disease, and the incubation period can span from months to years. The bacterium can survive for months in the environment. Diagnosing bTB in live animals is challenging and time-consuming, implying that detection and eradication of the infection is difficult. Key Findings: Norway has had a very low number of imported cattle during the past 10 years. However, some imports of small ruminants and camelids (llamas, alpacas, camels) have occurred. Import of cattle and camelids from countries with bTB in the animal population is assessed as a risk of introducing the bacterium to Norwegian cattle. This risk assessment concludes that introduction of bTB to Norway from imported cattle is unlikely based on the current situation with low number of imports. However, introduction by camelids is regarded as more likely. There is significant domestic trade and transport of beef and dairy cattle within Norway, sometimes without proper registration. If bTB is established in the country, cattle movements are likely to spread the infection between herds. Furthermore, direct and indirect transmission to other domestic species or free-ranging animals (semi-domesticated reindeer and wildlife) may occur, which may complicate the control of bTB in outbreak regions. Indirect transmission can occur via contaminated feeds, pastures, and salt licks that are shared with free-ranging animals. Many species of free-ranging animals are susceptible to M. bovis. Depending on population density and other ecological factors, these species may play the role as hosts and a source of infection for cattle, other livestock and humans. Based on experience from Europe, M. bovis is considered as extremely difficult to eradicate in a country if established in free-ranging species. Badgers, cervid species (i.e. red deer, reindeer, roe deer, and moose), and a growing population of wild boars are of special concern. A contingency plan that takes into account the risk of spread to wild fauna may thus be crucial for successful control of an outbreak with bTB. In periods of severe drought, import of roughage to Norway may be necessary. It is uncertain how well different feed materials and ensiling methods will enable survival of M. bovis. Therefore, restricting import of roughage to Norway to countries and regions certified as officially tuberculosis free (OTF), will reduce the risk of introduction to Norwegian cattle. In the event of introduction and establishment of M. bovis to Norwegian cattle, slurry may pose a risk of spread to domestic and wild animals due to survival of the bacterium in liquid manure. Survival in slurry is uncertain; however, a minimum of six months storage before spreading or alternatively disinfection of slurry will reduce the risk. Zoonotic transmission of bTB remains a relatively rare event, also in countries where the infection is present in animal populations. However, M. bovis can be transmitted by direct contact between animals and humans, through handling (farmers, veterinarians, and slaughterhouse workers) carcasses, and indirectly by consumption of unpasteurised milk and dairy products, but rarely through consumption of meat and meat products. Meat inspection is the key measure for surveillance of bTB in cattle and other domestic animals. Diagnosing bTB is challenging due to the nature of the disease and the lack of a gold standard test. Test-positive animals may not show visible lesions postmortem, and sensitive methods like cultivation and PCR depend on the presence of bacteria in sampled tissues. Any test-strategy aiming to increase the possibility to detect latent infected animals will result in a higher number of culled animals where the infection cannot be confirmed. Too extensive testing in low-risk herds can lead to false positives and must be balanced against the financial costs of restrictions and culling. Combining different tests (skin test, IFN-γ test, and boosted antibody tests) improve sensitivity, and this strategy is particularly advised for imported animals and during outbreak investigations. To achieve the best sensitivity, one should apply the tuberculin test at the same time as the IFN-γ test, followed by serology 10-30 days after the tuberculin test. Culling testpositive animals, and retest after at least 60 days of animals with an inconclusive test will reduce the risk of introducing M. bovis to Norway. While tuberculin tests are labor-intensive and costly, they are regarded as the methods of choice for surveillance in endemic regions. Serological assays like Enferplex show promise for general surveillance, however, the sensitivity is relatively low without prior skin-test. Ongoing studies are evaluating the test performance in bulk-milk screening. In culled animals with suspected lesions, real-time PCR, alongside culture, is recommended for quicker diagnosis. Whole-genome sequencing is the preferred tool for molecular surveillance and outbreak investigations.

• Josefsen, Terje Domaas; Mørk, Torill; Nymo, Ingebjørg Helena; Romano, Javier Sanchez & Tryland, Morten (2025). Prevalence and density of Elaphostrongylus rangiferi larvae in faecal samples of semi-domestic reindeer (Rangifer tarandus tarandus) in Norway 2013-16. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 67(1). doi: 10.1186/s13028-025-00793-x. Full text in Research Archive Show summary

  Background - The reindeer brainworm, Elaphostrongylus rangiferi, is a protostrongylid parasite of reindeer that has caused severe disease outbreaks in reindeer husbandry. E. rangiferi is considered ubiquitous in Norway, though most published prevalence studies are from Finnmark county only. In the present study, faecal samples were collected over three winter seasons (2013–2016) from eight herds of semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) distributed all over the reindeer herding area in Norway. Baermann’s technique was used to identify E. rangiferi larvae. The density of larvae was measured by counting and calculating number of larvae per gram faeces (LPG) in positive samples.<p> <p>Results - E. rangiferi larvae were found in 109 of 355 faecal samples (31%). All herds had positive samples at all sampling sessions. Prevalence in adults (> 1.5 years, n = 176) was 43% with significant difference between herds, varying from 25 to 78%. Prevalence in calves (< 1 year, n = 179) was 18%, and varied with sample month, being 10% in Oct-Jan (n = 153) and 69% in Mar-May (n = 26). Prevalence did not show statistically significant difference between males and females. LPG showed a highly skewed distribution, total median LPG being 38, range 2-700. Calves in Mar-May had significantly (P = 0.01) higher number of LPG (median 104) than calves in Oct-Jan (median 14) and adults (median 32). LPG did not differ significantly between males and females nor between herds, but there was a significant moderate positive correlation between herd prevalence and LPG (Spearman rho = 0.35, P < 0.01). Samples from individually marked adult reindeer with known age (n = 81) showed no significant difference in prevalence between young (2–5 years) and old (6–15 years) reindeer. LPG tended to be slightly reduced with age, but the reduction was not statistically significant (P = 0.07). Systematic yearly treatment with ivermectin was done in four herds, but any effect on E. rangiferi prevalence was not clear.<p> <p>Conclusions - This study confirms that E. rangiferi was ubiquitously present in all parts of the reindeer herding area in Norway during the study period. Differences in prevalence between herds were significant, and LPG in herds increased with increasing herd prevalence.

• Marin, Peter Michael; Tryland, Morten; Munyeme, Musso; Jubara, Ambrose Samuel; Matovu, Enock & Waiswa, Peter [Show all 13 contributors for this article] (2025). Elucidating the knowledge, attitude, and stigma associated with tuberculosis: a community based descriptive study in Wau and Jur River, South Sudan. Tropical Medicine and Health. ISSN 1348-8945. 53(1). doi: 10.1186/s41182-025-00696-7. Full text in Research Archive Show summary

  Background - Tuberculosis (TB) is a major public health problem in South Sudan. Inadequate knowledge, negative attitudes and perceived stigma may complicate the prevention efforts. This study describes knowledge, attitude, and stigma associated with TB among communities in Wau and Jur River, South Sudan.<p> <p>Methods - From March to May 2023, a cross-sectional study was conducted among 352 community members randomly selected from residential blocks. A validated structured questionnaire was used to collect the required data. Descriptive, bivariate and multivariate analyses were performed.<p> <p>Results - Out of 352 respondents, 51% (n = 180) were males and 49% (n = 172) were females. Majority 227 (64.5%) had poor knowledge about TB, meanwhile hearing about TB, age and level of education were associated factors. Fear of having TB was the major negative attitude (57.1%; n = 218), and most of the respondents (n = 327; 92.9%) had a perceived stigma towards TB, voicing that they disliked drinking or eating with people with TB and/or felt uncomfortable and kept their distance from people with TB.<p> <p>Conclusions - Communities have little knowledge, negative attitude and perceived stigma towards people with TB. Hence, tailored health messages using local languages, training of community volunteers to reach villages without accessibility and communication network are essential to improve TB prevention and control in South Sudan.

• Robertson, Lucy; Bukhvalova, Barbara Alexandra; Grahek-Ogden, Danica; Kausrud, Kyrre Linné; Skjerve, Eystein & Tryland, Morten [Show all 13 contributors for this article] (2024). Update on assessment of risk of introduction of Echinococcus multilocularis to mainland Norway. VKM Report. p. 1–51. Full text in Research Archive Show summary

  Det er betydelig risiko for at parasitten revens dvergbendelorm innføres og etablerer seg i Norge før dette oppdages gjennom overvåkning. Det er konklusjonen i en risikovurdering fra Vitenskapskomiteen for mat og miljø (VKM). Bakgrunn VKMs faggruppe for hygiene og smittestoffer har oppdatert den vitenskapelige vurderingen om mulig introduksjon og etablering av parasitten Echinococcus multilocularis (EM) i fastlands-Norge. Oppgaven er initiert av faggruppen selv. EM er også kjent som revens dvergbendelorm, og hundeeiere som krysser grensen er godt kjent med behandlingsregimet rundt dette. Parasitten lever i tarmen hos hundedyr, smågnagerer er mellomverten, men den kan også infisere mennesker. Sykdommen er sjelden, svært alvorlig og vanskelig å behandle. Uten behandling er sykdommen (alveolær ekinokokkose) vanligvis dødelig innen 10 år. Den forrige risikovurderingen ble publisert i 2012. Denne oppdateringen vurderer om situasjonen har endret seg, og om ny informasjon er tilgjengelig. Konklusjonene i den forrige vitenskapelige uttalelsen står seg fortsatt: Smittede hunder kan innføre parasitten til Norge. ‑ Det er en betydelig risiko for at revens dvergbendelorm innføres og etablerer seg før vi oppdager det, sier faglig ansvarlig Lucy Robertson, faglig leder av arbeidet. - Smitte av EM fra Sverige til Norge via rev er sannsynligvis et tidsspørsmål, men vi kan ikke anslå når det vil skje. Det er alvorlig; vi ser at i andre land, hvor parasitten har etablert seg hos rev og små gnagere, rammes også mennesker etter hvert. Metode Dataene ble samlet inn gjennom litteratursøk og undersøkelse av publiserte overvåkingsrapporter. Materialet oppdaterer eksisterende litteratur om: - overvåking av introduksjon av EM til fastlands-Norge - spredning av EM - import av ferskvarer kontaminerte med EM VKM har også vurdert hvor effektive de ulike kontrolltiltakene er. Resultater Et drøyt tiår etter at EM ble påvist i Sverige (2011), er forekomsten fortsatt lav og begrenset i utbredelse. Dette indikerer en langsom spredningshastighet. Det er ikke tegn til at parasitten har nærmet seg norskegrensen, EM er ikke påvist i fastlands-Norge, og analyser av importerte ferskvarer har ikke påvist EM. I dag er det krav om at hunder som krysser grensen til Norge skal være behandlet med ormemidler mot parasitter, men det er ikke dokumentert om hundeeiere følger reglene, eller i hvilken grad dette sjekkes ved land- og sjøgrensene. Usikkerhet De største usikkerhetene i vurderingen skyldes at utbruddet i Sverige er begrenset, og det er dermed lite tilgjengelige data. Vi mangler også informasjon om antall ubehandlede hunder som kommer inn i Norge. Risikovurderingen er egeninitiert, og arbeidet er utført av VKMs faggruppe for hygiene og smittestoffer. Faglig leder har vært Lucy Robertson. VKM utfører risikovurderinger fra oppdragsgivere og på eget initiativ, men beslutter ikke hvordan risiko håndteres.

• Marin, Peter Michael; Munyeme, Musso; Kankya, Clovice; Jubara, Ambrose Samuel; Matovu, Enock & Waiswa, Peter [Show all 13 contributors for this article] (2024). Medication nonadherence and associated factors in patients with tuberculosis in Wau, South Sudan: a cross- sectional study using the world health organization multidimensional adherence model. Archives of Public Health. ISSN 0778-7367. 82(1). doi: 10.1186/s13690-024-01339-9. Full text in Research Archive Show summary

  Background - Tuberculosis medication nonadherence is a multi-dimensional public health problem with serious consequences worldwide. There is little information available for medication nonadherence in South Sudan. This study assessed the proportion, reasons, and associated factors for nonadherence among patients with TB in Wau Municipality, South Sudan.<p> <p>Methods - A health facility based cross-sectional study was conducted among 234 tuberculosis (TB) patients receiving first line anti-TB regimen in Wau Municipality. Urine isoniazid metabolite testing (IsoScreen®) was used to determine nonadherence (visualized by negative test results) and a questionnaire was used to describe the reasons for nonadherence. Modified poisson regression with robust standard errors was performed since the proportion of nonadherence was < 10%, to identify nonadherence associated factors using the WHO Multidimensional adherence model.<p> <p>Results - Out of 234 participants, 24.8% (95% CI, 19.2 − 30.3) were nonadherent to the TB treatment regimen. At multivariate analysis, nonadherence was significantly associated with: relief of symptoms (APR 1.93, 95% CI 1.12 − 3.34, p = 0.018), alcohol use (APR 2.12, 95% CI 1.33 − 3.96, p = 0.019) and waiting time to receive drugs (APR 1.77, 95% CI 1.11 − 2.83, p = 0.017).<p> <p>Conclusion - Tuberculosis medication nonadherence was high, and it’s associated with patients’ relived of symptoms, alcohol use, and prolonged waiting time at health facility. Hence, addressing these barriers and the use of multifaceted interventions e.g. counseling, health education and improve appointments are crucial to reduce nonadherence among patients with TB in South Sudan.

• Kulabako, Christine Tricia; Neema, Stella; Ninsiima, Lesley Rose; Atuheire, Collins GK; Kal, David Onafruo & Atekyereza, Peter [Show all 8 contributors for this article] (2024). Understanding brucellosis: knowledge, perceptions, and self-reported prevalence among agro-pastoralists in Nakasongola, Uganda. BMC Infectious Diseases. 24. doi: 10.1186/s12879-024-09717-y. Full text in Research Archive Show summary

  Background Brucellosis is an infectious zoonotic disease that poses serious health threats around the world including Uganda. Brucellosis is caused by Brucella spp., the bacteria being transmitted via contact through skin breaks, via inhalation, or orally through the consumption of raw milk and other dairy products. The aim of this study was to investigate self-reported prevalence, knowledge, and perceptions towards brucellosis transmission, within agro-pastoralist communities in the Nakasongola district, central Uganda. Methods This study employed a cross-sectional survey design. A semi-structured questionnaire was developed and administered to 398 participants selected through convenience sampling method. The survey gathered information on socio-demographic characteristics, knowledge of brucellosis transmission, symptoms, preventive measures, and self-reported prevalence of brucellosis. Qualitative data involved the use of six focus group discussions, identifying factors for transmission based on their perceived level of risk or impact using ranking by proportional piling. Results A majority (99.2%, n = 398) had heard about brucellosis and 71.2% were aware of the zoonotic nature of the disease. There were varied responses regarding transmission routes, symptoms, and preventive measures. Self-reported prevalence was relatively high (55.5%). Following adjusted analysis, factors such as subcounty, source of income, knowledge about symptoms of brucellosis, whether brucellosis is treatable, perception, and living close to animals were statistically significant. Participants from Wabinyonyi had 2.7 higher odds of reporting brucellosis than those from Nabiswera, aOR = 2.7, 95%CI 1.4–5.5. Crop farming and livestock had much higher odds of reporting brucellosis than those earning from casual sources, aOR = 8.5, 95%C 1.8–40.1 and aOR = 14.4, 95%CI 3.1–67.6, respectively. Those who had knowledge about symptoms had 6.9 higher odds of reporting brucellosis than who mentioned fever, aOR = 4.5, 95%CI 2.3–18.3. Likewise, living close with animals and handling aborted fetuses (aOR = 0.4, 95%CI: 0.17–0.86), (aOR = 0.2,95% CI: 0.07-0.0.42,) had significantly lower odds for self-reported prevalence compared to those who believed did not cause brucellosis. Risk factors identified included, handling of aborted fetuses and living in close proximity with animals. Overall, there was a moderate statistical agreement in the ranking across the focus groups discussion (Wc = 0.48, p < 0.01; n = 6). Conclusion While awareness of brucellosis is high in the community, understanding of the transmission routes, clinical symptoms, and preventive measures varied. Investigating the understanding and assessing knowledge, perceptions and self-reported prevalence in this region indicated a necessity for risk communication strategies and community-based interventions to better control brucellosis transmission.

• Atuheire, Collins G. K.; Okwee-Acai, James; Taremwa, Martha; Terence, Odoch; Ssali, Sarah N. & Mwiine, Frank N. [Show all 9 contributors for this article] (2024). Descriptive analyses of knowledge, attitudes, and practices regarding rabies transmission and prevention in rural communities near wildlife reserves in Uganda: a One Health cross-sectional study. Tropical Medicine and Health. ISSN 1348-8945. 52(1). doi: 10.1186/s41182-024-00615-2. Full text in Research Archive Show summary

  Background Despite urban (domestic dog) rabies cycles being the main target for rabies elimination by 2030, syl‑ vatic (wildlife) rabies cycles can act as rabies spillovers especially in settlements contiguous to wildlife reserves. Rural communities next to wildlife reserves are characterized by unique socio-demographic and cultural practices includ‑ ing bat consumption, hunting for bushmeat, and non-vaccination of hunting dogs against rabies among others. This study aimed to compare the knowledge, attitudes, and practices (KAPs) related to rabies transmission and prevention in the three districts of Uganda; (1) Nwoya, neighboring Murchison Falls National Park (MFNP) in the north, (2) Kam‑ wenge neighboring Kibaale National Park (KNP), Queen Elizabeth National Park (QENP) and Katonga Game Reserve (KGR) in the west, and (3) Bukedea, neighboring Pian Upe Game Reserve (PUGR) in the east of Uganda. Methods A community-based cross-sectional survey was conducted in settlements contiguous to these wildlife reserves. Using a semi-structured questionnaire, data were collected from 843 households owning dogs and livestock. Data were collected between the months of January and April 2023. Stratified univariate analyses by district were carried out using the Chi-square test for independence and Fisher’s exact test to compare KAPs in the three study districts. Results The median age of study participants was 42 years (Q1, Q3=30, 52) with males comprising the major‑ ity (67%, n=562). The key fndings revealed that participants from the Nwoya district in the north (MFNP) had little knowledge about rabies epidemiology (8.5%, n=25), only 64% (n=187) of them knew its signs and symptoms such as a rabid dog presenting with aggressiveness and showed negative attitudes towards prevention measures (15.3%, n=45). Participants in the Kamwenge district-west (KNP, QENP, and KGR) had little knowledge and negative attitude towards wildlife–human interaction pertaining to rabies transmission and prevention especially those with no or primary level of education (20.9%, n=27) while participants from Bukedea in the east (PUGR) had remarkedly poor practices towards rabies transmission, prevention, and control (37.8%, n=114). Conclusions Rabies from sylvatic cycles remains a neglected public health threat in rural communities sur‑ rounding national parks and game reserves in Uganda. Our study findings highlight key gaps in knowledge, atti‑ tudes, and practices related to rabies transmission and prevention among such communities. Communication and action between veterinary services, wildlife authority, public health teams, social science and community leaders through available community platforms is key in addressing rabies among the sympatric at-risk communities in Uganda.

• Andersen-Ranberg, Emilie; Nymo, Ingebjørg Helena; Jokelainen, Pikka; Emelyanova, Anastasia; Jore, Solveig & Laird, Brian [Show all 22 contributors for this article] (2024). Environmental stressors and zoonoses in the Arctic: Learning from the past to prepare for the future. Science of the Total Environment. ISSN 0048-9697. 957. doi: 10.1016/j.scitotenv.2024.176869. Full text in Research Archive Show summary

  The risk of zoonotic disease transmission from animals to humans is elevated for people in close contact with domestic and wild animals. About three-quarters of all known human infectious diseases are zoonotic, and potential health impacts of these diseases are higher where infectious disease surveillance and access to health care and public health services are limited. This is especially the case for remote circumarctic regions, where drivers for endemic, emerging, and re-emerging zoonotic diseases include anthropogenic influences, such as pollution by long-range transport of industrial chemicals, climate change, loss of biodiversity and ecosystem alterations. In addition to these, indirect effects including natural changes in food web dynamics, appearance of invasive species and thawing permafrost also affect the risk of zoonotic disease spill-over. In other words, the Arctic represents a changing world where pollution, loss of biodiversity and habitat, and maritime activity are likely driving forward occurrence of infectious diseases. As a broad international consortium with a wide range of expertise, we here describe a selection of case studies highlighting the importance of a One Health approach to zoonoses in the circumarctic, encompassing human health, animal health, and environmental health aspects. The cases highlight critical gaps in monitoring and current knowledge, focusing on environmental stressors and lifestyle factors, and they are examples of current occurrences in the Arctic that inform on critically needed actions to prepare us for the future. Through these presentations, we recommend measures to enhance awareness and management of existing and emerging zoonoses with epidemic and pandemic potential while also focusing on the impacts of various environmental stressors and lifestyle factors on zoonoses in the Arctic.

• Atuheire, Collins G. K.; Okwee-Acai, James; Taremwa, Martha; Ssajjakambwe, Paul; Munyeme, Musso & Kankya, Clovice [Show all 11 contributors for this article] (2024). Households neighboring wildlife protected areas may be at a higher risk of rabies than those located further away: a community-based cross-sectional cohort study at Pian Upe game reserve, Bukedea district, Eastern Uganda. Frontiers in Tropical Diseases. 5. doi: 10.3389/fitd.2024.1272141. Full text in Research Archive Show summary

  Introduction: This study examines rabies incidence and associated risk factors at the interface between wildlife and human communities near Pian-Upe game reserve in Eastern Uganda. We hypothesized that human settlements in closer proximity to the reserve would exhibit higher rabies risk compared to those located further away.<p> <p>Methods: Using a standard questionnaire, households within <4, 4-14, and >14 km from the Pian Upe game reserve in Bukedea District were interviewed. Data on socio-demographic characteristics, recent rabid animal bites, and suspected human and livestock rabies cases for the past year (2023) were collected after seeking informed consent. Descriptive statistics were used to analyze sociodemographic information and incidence data, while separate binomial generalized linear models with log-link function were used to identify predictors of rabies incidence and mortality. <p>Results: Between January and March 2023, 302 participants were interviewed. Respondents had an average age of 44 years with 34% (n=103) being female. All households owned at least one dog, though only 47% (n=142) had vaccinated their dogs against rabies in the past year. Additionally, 39% (n=118) of respondents used dogs for hunting. Rabies annual incidence increased with decreasing distance to the game reserve (7.5 to 15.7% for humans, for the dogs, and 5.0 to 9.8% for livestock, including cows, goats and sheep). Significant factors associated with rabies in humans included primary education level (aRR=3.8, 95% CI 1.0-23.7) and grazing livestock in the reserve (aRR=5.30, 95%CI 1.0-40.3). Mortality was associated with fetching firewood from the game reserve (aRR=4.7, 95%CI 1.3-17.5). <p>Conclusions: This study reveals that there is an increased risk of rabies for domesticated animals and people located within proximity to the game reserve. Further efforts to prevent the spread of rabies could include increasing education and awareness for communities along with targeted dog vaccination in settlements surrounding wildlife protected areas.

• Tryland, Morten; Romano, Javier Sanchez; Nymo, Ingebjørg Helena; Mørk, Torill; Þórarinsdóttir, Rán & Breines, Eva Marie [Show all 9 contributors for this article] (2023). A Screening for Virus Infections among Wild Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Iceland, 2017–2019. Viruses. 15(2). doi: 10.3390/v15020317. Full text in Research Archive Show summary

  A winter population of around 4000–5000 wild Eurasian tundra reindeer (<i>Rangifer t. tarandus</i>) in the eastern part of Iceland represents descendants from 35 semi-domesticated reindeer imported to Iceland from Finnmark county, Norway, in 1787. While previous studies have indicated that they host fewer parasite species as compared to reindeer in Fennoscandia, little information exists on their exposure to reindeer viral pathogens. The aim of this study was to investigate blood from hunted reindeer for antibodies against alphaherpesvirus and gammaherpesviruses (malignant catarrhal fever viruses, MCFV), pestivirus, bluetongue virus, and Schmallenberg virus, and to investigate nasal and oral mucosal membrane swab samples for the presence of parapoxvirus-specific DNA. Blood samples collected during the hunting seasons in 2017 (n = 40), 2018 (n = 103), and 2019 (n = 138) were tested for viral antibodies using enzyme-linked immunosorbent assays (ELISA). Screening for parapoxvirus DNA was conducted on swab samples from 181 reindeer by polymerase chain reaction (PCR), targeting the B2L and GIF genes. Antibodies against pestivirus were detected in two animals from 2017, and antibodies against MCFV were detected in two reindeer from 2018. No antibodies were detected against the other viruses tested. Parapoxvirus-specific DNA was detected in nasal swab samples from two animals sampled in 2019. This study suggests that the investigated viral infections are either not present or present at a low prevalence only, probably not representing a major health threat to this reindeer population. The lack of exposure to alphaherpesvirus, an enzootic pathogen in most investigated <i>Rangifer</i> populations, was unexpected.

• Philippot, Karin Wallin; Baron, Jerome; Romano, Javier Sanchez; Rautiainen, Heidi; Frössling, Jenny & Nymo, Ingebjørg Helena [Show all 9 contributors for this article] (2023). Infectious keratoconjunctivitis in semi-domesticated reindeer (Rangifer tarandus tarandus): a questionnaire-based study among reindeer herders in Norway and Sweden. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 65(34). doi: 10.1186/s13028-023-00694-x. Full text in Research Archive Show summary

  Background - The effects of climate change, loss of pastureland to other land usage and presence of large carnivores are the main reasons for the increase in supplementary feeding of semi-domesticated reindeer (Rangifer tarandus tarandus) in Fennoscandia over the last decades. Feeding might expose reindeer to stress and increased animal-to-animal contact, leading to an increased risk of infectious disease transmission, such as infectious keratoconjunctivitis (IKC). As it can develop rapidly and be very painful, IKC is described as an important animal welfare concern and a potential source of economic loss. The aim of this study was to investigate the current presence of IKC and potential associations between IKC and supplementary feeding through an online questionnaire survey, distributed among reindeer herders in Norway and Sweden in 2021.<p> <p>Results - Seventy-six reindeer herders (33 from Norway and 43 from Sweden) responded to the questionnaire, representing 6% and 4% of the registered reindeer herding groups in Norway and Sweden, respectively. Infectious keratoconjunctivitis was common, with 54 (71%) of the 76 herders that responded having observed clinical signs during the past 10 years. These signs were mainly observed as increased lacrimation, causing “wet cheeks”, but also as keratitis and conjunctivitis. Autumn and winter were the seasons in which IKC was observed most. The herders reported several measures, such as slaughter and isolation of affected reindeer, to counteract the spread of disease. The herding year 2019/2020 was associated with reports of outbreaks of IKC in herds as well as being the herding year where most herders (80%) had performed supplementary feeding. A significant association was found between IKC and feeding performed in an enclosure (odds ratio = 15.20), while feeding on free-range areas had a non-significant, negative, relationship with the appearance of IKC outbreaks (odds ratio = 0.29). Finally, there was a trend in the data suggesting that IKC affected calves especially.<p> <p>Conclusions - Infectious keratoconjunctivitis is a common disease, mainly observed in winter and autumn. It usually has mild to moderately severe clinical signs. Our results imply that IKC is associated with stress and feeding situations and that calves might be more susceptible than adults, however, this needs to be confirmed with further studies, preferably at an individual animal level.

• Tranulis, Michael A. & Tryland, Morten (2023). The Zoonotic Potential of Chronic Wasting Disease—A Review. Foods. 12(4), p. 1–20. doi: 10.3390/foods12040824. Full text in Research Archive Show summary

  Prion diseases are transmissible neurodegenerative disorders that affect humans and ruminant species consumed by humans. Ruminant prion diseases include bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep and goats and chronic wasting disease (CWD) in cervids. In 1996, prions causing BSE were identified as the cause of a new prion disease in humans; variant Creutzfeldt-Jakob disease (vCJD). This sparked a food safety crisis and unprecedented protective measures to reduce human exposure to livestock prions. CWD continues to spread in North America, and now affects free-ranging and/or farmed cervids in 30 US states and four Canadian provinces. The recent discovery in Europe of previously unrecognized CWD strains has further heightened concerns about CWD as a food pathogen. The escalating CWD prevalence in enzootic areas and its appearance in a new species (reindeer) and new geographical locations, increase human exposure and the risk of CWD strain adaptation to humans. No cases of human prion disease caused by CWD have been recorded, and most experimental data suggest that the zoonotic risk of CWD is very low. However, the understanding of these diseases is still incomplete (e.g., origin, transmission properties and ecology), suggesting that precautionary measures should be implemented to minimize human exposure.

• Lamsal, Alaka; Tryland, Morten; Paulsen, Katrine M.; Romano, Javier Sanchez; Nymo, Ingebjørg H. & Stiasny, Karin [Show all 9 contributors for this article] (2023). Serological screening for tick-borne encephalitis virus in eight Norwegian herds of semi-domesticated reindeer (Rangifer tarandus tarandus). Zoonoses and Public Health. ISSN 1863-1959. 70, p. 692–698. doi: 10.1111/zph.13060. Full text in Research Archive Show summary

  Tick-borne encephalitis virus (TBEV) is found in Ixodes ricinus ticks throughout the area where viable tick populations exist. In Norway, TBEV is found in I. ricinus from the south coast until Brønnøy municipality in Nordland County and the range of the vector is expanding due to changes in climate, vegetation, host animals and environmental conditions. TBEV might thus have the potential to establish in new areas when I. ricinus expand its geographical distribution. At present, there is little knowledge on the status of the virus in high-altitude areas of inland regions in Norway. It has previously been indicated that reindeer may be an important sentinel species and indicator of the spread of ticks and TBEV in high-altitude regions. In this study, 408 semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) from eight herds, from Tana in Troms and Finnmark County in northern Norway to Filefjell in Innlandet and Viken Counties in southern Norway, were screened for TBEV antibodies using a commercial enzyme-linked immunosorbent assay (ELISA). We found 16 TBEV reactive reindeer samples by ELISA; however, these results could not be confirmed by the serum neutralization test (SNT). This could indicate that a flavivirusand not necessarily TBEV, may be circulating among Norwegian semi-domesticated reindeer. The results also indicate that TBEV was not enzootic in Norwegian semi-domesticated reindeer in 2013–2015. This knowledge is important as an information base for future TBEV and flavivirus surveillance in Norway.

• Nymo, Ingebjørg Helena; Siebert, Ursula; Baechlein, Christine; Postel, Alexander; Breines, Eva Marie & Lydersen, Christian [Show all 8 contributors for this article] (2023). Pathogen Exposure in White Whales (Delphinapterus leucas) in Svalbard, Norway. Pathogens. ISSN 2076-0817. 12(1). doi: 10.3390/pathogens12010058. Full text in Research Archive Show summary

  The Svalbard white whale (Delphinapterus leucas) population is one of the smallest in the world, making it particularly vulnerable to challenges such as climate change and pathogens. In this study, serum samples from live captured (2001-2016) white whales from this region were investigated for influenza A virus (IAV) antibodies (Abs) (n = 27) and RNA (n = 25); morbillivirus (MV) Abs (n = 3) and RNA (n = 25); Brucella spp. Abs; and Toxoplasma gondii Abs (n = 27). IAV Abs were found in a single adult male that was captured in Van Mijenfjorden in 2001, although no IAV RNA was detected. Brucella spp. Abs were found in 59% of the sample group (16/27). All MV and T.&amp;nbsp;gondii results were negative. The results show that Svalbard white whales have been exposed to IAV and Brucella spp., although evidence of disease is lacking. However, dramatic changes in climate and marine ecosystems are taking place in the Arctic, so surveillance of health parameters, including pathogens, is critical for tracking changes in the status of this vulnerable population.

• Tryland, Morten; Cunha, Cristina Wetzel; Fuchs, Boris; Breines, Eva Marie; Li, Hong & Jokelainen, Pikka [Show all 7 contributors for this article] (2023). A serological screening for potential viral pathogens among semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Finland. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 65(8). doi: 10.1186/s13028-023-00671-4. Full text in Research Archive Show summary

  Reindeer herding and husbandry is a traditional and important livelihood in Fennoscandia, and about 200,000 semi-domesticated reindeer are herded in Finland. Climatic changes, leading to ice-locked winter pastures, and encroachment of pasture-land have led to changes in reindeer husbandry, increasing the extent of supplementary or full ration feeding, which has become very common in Finland. Keeping reindeer in corrals or gathering them at permanent feeding sites will increase nose-to-nose contact between animals and they may be exposed to poor hygienic conditions. This may impact the epidemiology of infectious diseases, such as viral infections. The aim of this study was to investigate Finnish semi-domesticated reindeer for exposure to viral pathogens. Blood samples were collected from 596 reindeer (358 calves, 238 adults) in 2015, from nine reindeer slaughterhouses, representing most of the reindeer herding regions in Finland. Plasma samples were investigated for antibodies against a selection of known and potential reindeer viral pathogens by using enzyme linked immunosorbent assays (ELISA).

• Shakya, Ruchika; Tryland, Morten; Vikse, Rose; Romano, Javier Sanchez; Åsbakk, Kjetil & Nymo, Ingebjørg Helena [Show all 16 contributors for this article] (2022). Inkoo and Sindbis viruses in blood sucking insects, and a serological study for Inkoo virus in semi-domesticated Eurasian tundra reindeer in Norway. Virology Journal. 19(1). doi: 10.1186/s12985-022-01815-0. Full text in Research Archive Show summary

  Background: Mosquito-borne viruses pose a serious threat to humans worldwide. There has been an upsurge in the number of mosquito-borne viruses in Europe, mostly belonging to the families Togaviridae, genus Alphavirus (Sindbis, Chikungunya), Flaviviridae (West Nile, Usutu, Dengue), and Peribunyaviridae, genus Orthobunyavirus, California serogroup (Inkoo, Batai, Tahyna). The principal focus of this study was Inkoo (INKV) and Sindbis (SINV) virus circulating in Norway, Sweden, Finland, and some parts of Russia. These viruses are associated with morbidity in humans. However, there is a knowledge gap regarding reservoirs and transmission. Therefore, we aimed to determine the prevalence of INKV and SINV in blood sucking insects and seroprevalence for INKV in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Norway.<p> <p>Materials and methods: In total, 213 pools containing about 25 blood sucking insects (BSI) each and 480 reindeer sera were collected in eight Norwegian reindeer summer pasture districts during 2013–2015. The pools were analysed by RT-PCR to detect INKV and by RT-real-time PCR for SINV. Reindeer sera were analysed for INKV-specifc IgG by an Indirect Immunofuorescence Assay (n=480, IIFA) and a Plaque Reduction Neutralization Test (n=60, PRNT). <p>Results: Aedes spp. were the most dominant species among the collected BSI. Two of the pools were positive for INKV-RNA by RT-PCR and were confrmed by pyrosequencing. The overall estimated pool prevalence (EPP) of INKV in Norway was 0.04%. None of the analysed pools were positive for SINV. Overall IgG seroprevalence in reindeer was 62% positive for INKV by IIFA. Of the 60 reindeer sera- analysed by PRNT for INKV, 80% were confrmed positive, and there was no cross-reactivity with the closely related Tahyna virus (TAHV) and Snowshoe hare virus (SSHV). <p>Conclusion: The occurrence and prevalence of INKV in BSI and the high seroprevalence against the virus among semi-domesticated reindeer in Norway indicate that further studies are required for monitoring this virus. SINV was not detected in the BSI in this study, however, human cases of SINV infection are yearly reported from other regions such as Rjukan in south-central Norway. It is therefore essential to monitor both viruses in the human population. Our fndings are important to raise awareness regarding the geographical distribution of these mosquito-borne viruses in Northern Europe.

• Tryland, Morten; Nymo, Ingebjørg Helena; Romano, Javier Sanchez & Riseth, Jan Åge (2022). Husbandry and Diseases of Semi-Domesticated Eurasian Tundra Reindeer in Fennoscandia, The Management of enclosed and domesticated deer. Springer Nature. ISSN 9783031053856. p. 413–447. doi: 10.1007/978-3-031-05386-3_19. Full text in Research Archive Show summary

  This chapter presents the most relevant diseases of semi-domesticated Eurasian tundra reindeer (Rangifer t. tarandus) in a historical and contemporary perspective. Human relation to these animals is very ancient, and disease history is context dependent. Historical epizootics, such as anthrax and the “Reindeer pest,” could be devastating for reindeer and man, but not always well documented in older sources. Others, such as necrobacillosis, were known to be associated with high animal density and corralling due to milking practice. Contemporary diseases, such as rumen acidosis and ruminal tympani, are usually connected to feeding, whereas diseases like infectious keratoconjunctivitis and contagious ecthyma are associated with high animal density and stress. The ongoing and rapid transition from traditional reindeer herding to increased husbandry and feeding may lead to an altered disease prevalence, possibly introducing new pathogens and altering the epidemiology and appearance of “old” pathogens. Chronic wasting disease is also a serious threat, but so far not detected in semi-domesticated reindeer. In addition, climatic changes may contribute to altered ecosystems, including new distribution patterns for insects, which can be vectors for reindeer pathogens. Changing conditions for reindeer herding create new challenges for both reindeer health and the sustainability of the traditional reindeer herding industry.

• Tryland, Morten; Åhman, Birgitta & Romano, Javier Sanchez (2022). Health and diseases of semi-domesticated reindeer in a climate change perspective. In Horstkotte, Tim; Holand, Øystein; Kumpula, Jouko & Moen, Jon (Ed.), Reindeer Husbandry and Global Environmental Change. Routledge. ISSN 9781003118565. p. 249–262. doi: 10.4324/9781003118565-18. Full text in Research Archive Show summary

  Climate change may affect reindeer herding and the health and disease of reindeer in several ways. One way of mitigating such changes is supplementary feeding, both in corrals and by bringing fodder to the animals on natural pastures. Feeding, when the right feed and feeding regime are used, may compensate for the loss of natural pastures and increase animal welfare. However, feeding may also cause issues with health and disease. These challenges may be associated with the feed and feeding regimes themselves, but also indirectly, by creating increased animal-to-animal contact and through the difficulty of maintaining hygienic conditions in corrals. In addition, climate change may have an impact on the presence of arthropod species and populations, such as ticks, mosquitoes and midges. These insects may cause increased levels of stress for the animals but can also be vectors for pathogens that may cause severe disease outbreaks, animal welfare issues and economic loss for reindeer herders. This chapter briefly presents the diseases and health problems that are directly or indirectly associated with reindeer feeding, as well as health challenges associated with arthropods and vector-borne diseases that are expected to be affected by climate change in the Arctic and sub-Arctic regions.

• Tryland, Morten (2022). Parapoxvirus infections in northern species and populations. In Tryland, Morten (Eds.), Arctic One Health - Challenges for Northern Animals and People. Springer Nature. ISSN 9783030878528. p. 427–436. Full text in Research Archive Show summary

  This multidisciplinary book discusses the manifold challenges arctic marine and terrestrial wildlife, ecosystems and people face these times. Major health threats caused by the consequences of climate change, environmental pollution and increasing tourism in northern regions around the globe are explored. The most common infectious diseases in wild and domesticated arctic animals are reviewed and the impact they could have on circumpolar ecosystems as well as on the lives of arctic people are profoundly discussed. Moreover, the book reviews arctic hunting, herding and food conservation strategies and introduces veterinary medicine in remote indigenous communities. "Arctic One Health" is authored by experts based in arctic regions spanning from North America over Europe to Asia to cover a broad range of topics and perspectives. The book addresses researchers in Veterinary Medicine, Ecology, Microbiology and Anthropology. The book contributes towards achieving the UN Sustainable Developmental Goals, in particular SDG 15, Life on Land.

• Tryland, Morten (2022). Semi-domesticated reindeer, health and animal welfare. In Tryland, Morten (Eds.), Arctic One Health - Challenges for Northern Animals and People. Springer Nature. ISSN 9783030878528. p. 551–557. Full text in Research Archive Show summary

  This multidisciplinary book discusses the manifold challenges arctic marine and terrestrial wildlife, ecosystems and people face these times. Major health threats caused by the consequences of climate change, environmental pollution and increasing tourism in northern regions around the globe are explored. The most common infectious diseases in wild and domesticated arctic animals are reviewed and the impact they could have on circumpolar ecosystems as well as on the lives of arctic people are profoundly discussed. Moreover, the book reviews arctic hunting, herding and food conservation strategies and introduces veterinary medicine in remote indigenous communities. "Arctic One Health" is authored by experts based in arctic regions spanning from North America over Europe to Asia to cover a broad range of topics and perspectives. The book addresses researchers in Veterinary Medicine, Ecology, Microbiology and Anthropology. The book contributes towards achieving the UN Sustainable Developmental Goals, in particular SDG 15, Life on Land.

• Hueffer, Karsten; Tryland, Morten & Dresvyanikova, Svetlana (2022). Rabies in the Arctic. In Tryland, Morten (Eds.), Arctic One Health - Challenges for Northern Animals and People. Springer Nature. ISSN 9783030878528. p. 211–226. doi: 10.1007/978-3-030-87853-5_9. Full text in Research Archive Show summary

  Rabies is caused by rabies virus in the family Rhabdoviridae, genus Lyssavirus. The virus infects warm-blooded animals and causes severe neurological disease that is usually fatal once clinical signs are manifest. Rabies has been detected in every continent apart from Antarctica. The arctic fox (Vulpes lagopus) is the main reservoir of the virus in the circumpolar Arctic, but in some regions, where the distribution of the arctic and the red fox (Vulpes vulpes) overlap, the red fox may contribute to the epidemiology of the disease. Dogs (Canis familiaris) are also affected and may contribute to the risk of contracting rabies for humans. Historical sources describe diseases comparable to rabies (e.g., “dog madness”) in arctic regions, but the disease was typically not diagnosed until around the 1950s in different parts of these regions. Four different rabies virus variants have been detected in arctic regions. Due to the general remoteness of arctic regions and restrictions on the availability of veterinary and health care, rabies diagnostics and management may be challenging. The epidemiology of arctic rabies is associated with the population dynamics of the reservoir hosts. Climate change and increased human encroachment of wildlife habitats will impact the epidemiology of the disease, but the effects may be challenging to predict and may also vary between different regions of the circumpolar Arctic.

• Nymo, Ingebjørg Helena; Fuglei, Eva; Mørk, Torill; Breines, Eva Marie; Holmgren, Karin Elisabeth & Davidson, Rebecca K. [Show all 7 contributors for this article] (2022). Why are Svalbard Arctic foxes Brucella spp. seronegative? Polar Research. ISSN 0800-0395. 41. doi: 10.33265/polar.v41.7867. Full text in Research Archive Show summary

  Arctic foxes (Vulpes lagopus) are susceptible to smooth Brucella (s-Brucella) infection and may be exposed to such bacteria through the consumption of infected marine mammals, as implied by the finding of s-Brucella antibodies in polar bears (Ursus maritimus). Arctic foxes in Svalbard have not previously been investigated for s-Brucella antibodies, but such antibodies have been detected in Arctic foxes in Iceland, Alaska (USA) and Russia. We investigated blood from Svalbard Arctic foxes for s-Brucella antibodies using an indirect enzyme-linked immunosorbent assay (iELISA). The animals (0–13 years old) were either caught by fur trappers (1995–2003, n = 403) or found dead (1995 and 2003, n = 3). No seropositive animals were detected. Morbidity and mortality due to the infection cannot be ruled out. However, no known, large disease outbreaks of unknown aetiology have been reported. Furthermore, it is unlikely that the Svalbard Arctic fox is resistant to infection as Arctic foxes from other populations are susceptible, and there is circumpolar connectivity between populations. The discrepancy between the findings in Iceland and Svalbard is surprising as both populations are on islands with no known local sources of exposure to s-Brucella other than marine mammals. However, our negative findings suggest that marine mammals may not be a major source of infection for this species. Comparative investigations are needed in order to draw conclusions regarding the epizootiology of s-Brucella in Arctic foxes in Svalbard and Iceland.

• Costa, Helena Sofia Gomes; Klein, Joern; Breines, Eva Marie; Nollens, Hendrik H.; Matassa, Keith & Garron, Mendy [Show all 10 contributors for this article] (2021). A Comparison of Parapoxviruses in North American Pinnipeds. Frontiers in Veterinary Science. 8. doi: 10.3389/fvets.2021.653094. Full text in Research Archive Show summary

  Parapoxviruses cause nodular lesions on the skin and mucosal membranes of pinnipeds and infections by these viruses have been documented worldwide. Seal parapoxvirus is currently classified as a tentative species of the Parapoxvirus genus. Tissue or swab samples were analyzed from 11 pinnipeds of different host species undergoing rehabilitation on the east and west coasts of the United States of America (USA) that were positive for parapoxvirus. The aim of the study was to compare parapoxvirus sequences of fragments of the B2L, DNA polymerase, GIF and viral interleukin-10 ortholog (vIL-10) genes and to examine the evolutionary relationship between viruses detected in different pinniped species and at different locations with other members of the Parapoxvirus genus, such as Orf virus (ORFV), Bovine papular stomatitis virus (BPSV) and Pseudocowpox virus (PCPV). The sequence analysis showed that the parapoxvirus sequences from the pinnipeds differed significantly from those found in terrestrial hosts and that they formed a separate cluster within the genus. Our results suggest that transmission of the same parapoxvirus strain is possible between different species, including between members of different families (phocids and otariids). Animals belonging to the same species but living in distant geographic locations presented genetically distant parapoxviruses. The findings of this study demonstrate that sealpox lesions in pinnipeds of different species are caused by viruses that belong to the Parapoxvirus genus but have significant genetic differences compared to the established virus species in terrestrial hosts, thus strongly supporting the classification of pinniped parapoxvirus as a new species of the genus.

• Rinaldo, Christine Hanssen; Nymo, Ingebjørg Helena; Romano, Javier Sanchez; Breines, Eva Marie; Murguzur, Francisco Javier Ancin & Tryland, Morten (2021). Serological evidence of hepatitis e virus infection in semi-domesticated eurasian tundra reindeer (Rangifer tarandus tarandus) in norway. Pathogens. ISSN 2076-0817. 10(12), p. 1–12. doi: 10.3390/pathogens10121542. Full text in Research Archive Show summary

  Hepatitis E virus (HEV) is a common cause of viral hepatitis in humans. In developing countries, HEV-infections seem to be mainly associated with pigs, but other animal species may be involved in viral transmission. Recently, anti-HEV antibodies were detected in Norwegian wild reindeer. Here, we investigated anti-HEV seroprevalence in Norwegian semi-domesticated reindeer, animals in closer contact with humans than their wild counterparts. Blood samples (n = 516) were obtained from eight reindeer herds during the period 2013–2017 and analysed with a commercial enzyme-linked immunosorbent assay designed for detecting anti-HEV antibodies in livestock. Antibodies were found in all herds and for all sampling seasons. The overall seroprevalence was 15.7% (81/516), with adults showing a slightly higher seroprevalence (18.0%, 46/256) than calves (13.5%, 35/260, p = 0.11). The seroprevalence was not influenced by gender or latitude, and there was no temporal trend (p > 0.15). A positive association between the presence of anti-HEV antibodies and antibodies against alphaherpesvirus and pestivirus, detected in a previous screening, was found (p < 0.05). We conclude that Norwegian semi-domesticated reindeer are exposed to HEV or an antigenically similar virus. Whether the virus is affecting reindeer health or infects humans and poses a threat for human health remains unknown and warrants further investigations.

• Tryland, Morten; Lydersen, Christian; Kovacs, Kit Maureen; Rafter, Espen & Thoresen, Stein Istre (2021). Serum biochemistry and haematology in wild and captive bearded seals (Erignathus barbatus) from Svalbard, Norway. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 63(1), p. 1–7. doi: 10.1186/s13028-021-00598-8. Full text in Research Archive Show summary

  Background - Health assessment of seals in captivity include haematology and serum biochemistry measurements. Because such parameters differ between species, it is crucial to have species-specific reference values for the interpretation of clinical samples. Furthermore, differences in nutrition and environment, life cycles as well as seasonal/annual cycles and varying physiological conditions can potentially affect serum chemistry and haematology parameters. Blood samples from four captive adult bearded seals (initially caught as pups in Svalbard, Norway, now held at Polaria, an Arctic experience centre in Tromsø, Norway) collected over a 16-month period were analysed for haematology (n = 22) and serum chemistry (n = 25) parameters. Serum chemistry analyses were also conducted on blood samples from 74 wild bearded seals (1995–2007) collected from Svalbard, Norway.<p> <p>Results - We found higher activity of creatine kinase (CK) and higher concentrations of cortisol in the wild animals when compared to the captive seals, probably reflecting the physical restraint and concomitant stress induced during sampling. For the captive bearded seals, we did not find marked differences in haematology or serum chemistry parameters throughout the different seasons of sampling.<p> <p>Conclusions - This study presents haematology and serum chemistry reference values for captive and wild bearded seals. Comparing physiological parameters for captive seals with wild seals indicated that having wild-caught bearded seals under the conditions offered at Polaria for several years did not markedly affect physiological parameters of the animals, and that training may have helped to alleviate stress associated with blood sampling and veterinary inspection.

• Sunde, Marianne; Ramstad, Silje N.; Rudi, Knut; Porcellato, Davide; Ravi, Anuradha & Ludvigsen, Jane [Show all 11 contributors for this article] (2021). Plasmid-associated antimicrobial resistance and virulence genes in Escherichia coli in a high arctic reindeer subspecies. Journal of Global Antimicrobial Resistance. ISSN 2213-7165. 26, p. 317–322. doi: 10.1016/j.jgar.2021.06.003. Full text in Research Archive Show summary

  Objectives In extreme environments, such as the Arctic region, the anthropogenic influence is low and the presence of antimicrobial-resistant bacteria is unexpected. In this study, we screened wild reindeer (Rangifer tarandus platyrhynchus) from the Svalbard High Arctic Archipelago for antimicrobial-resistant Escherichia coli and performed in-depth strain characterisation. Methods Using selective culturing of faecal samples from 55 animals, resistant E. coli were isolated and subjected to minimum inhibitory concentration (MIC) determination, conjugation experiments and whole-genome sequencing. Results Twelve animals carried antimicrobial-resistant E. coli. Genomic analysis showed IncF plasmids as vectors both for resistance and virulence genes in most strains. Plasmid-associated genes encoding resistance to ampicillin, sulfonamides, streptomycin and trimethoprim were found in addition to virulence genes typical for colicin V (ColV)-producing plasmids. Comparison with previously reported IncF ColV plasmids from human and animal hosts showed high genetic similarity. The plasmids were detected in E. coli sequence types (STs) previously described as hosts for such plasmids, such as ST58, ST88 and ST131. Conclusion Antimicrobial-resistant E. coli were detected from Svalbard reindeer. Our findings show that successful hybrid antimicrobial resistance–ColV plasmids and their host strains are widely distributed also occurring in extreme environmental niches such as arctic ecosystems. Possible introduction routes of resistant bacterial strains and plasmids into Svalbard ecosystems may be through migrating birds, marine fish or mammals, arctic fox (Vulpes lagopus) or via human anthropogenic activities such as tourism.

• Romano, Javier Sanchez; Omazic, Anna; Leijon, Mikael; Hagström, Åsa; Tryland, Morten & Kantanen, Juha [Show all 10 contributors for this article] (2021). Screening of Eurasian Tundra Reindeer for Viral Sequences by Next-Generation Sequencing. International Journal of Environmental Research and Public Health (IJERPH). ISSN 1661-7827. 18(12). doi: 10.3390/ijerph18126561. Full text in Research Archive Show summary

  Reindeer husbandry is essential for the livelihood and culture of indigenous people in the Arctic. Parts of the herding areas are also used as pastures for farm animals, facilitating potential transmission of viruses between species. Following the Covid-19 pandemic, viruses circulating in the wild are receiving increased attention, since they might pose a potential threat to human health. Climate change will influence the prevalence of infectious diseases of both humans and animals. The aim of this study was to detect known and previously unknown viruses in Eurasian tundra reindeer. In total, 623 nasal and 477 rectal swab samples were collected from reindeer herds in Fennoscandia, Iceland, and Eastern Russia during 2016–2019. Next-generation sequencing analysis and BLAST-homology searches indicated the presence of viruses of domesticated and wild animals, such as bovine viral diarrhea virus, bovine papillomavirus, alcephaline herpesvirus 1 and 2, deer mastadenovirus B, bovine rotavirus, and roe deer picobirnavirus. Several viral species previously found in reindeer and some novel species were detected, although the clinical relevance of these viruses in reindeer is largely unknown. These results indicate that it should be possible to find emerging viruses of relevance for both human and animal health using reindeer as a sentinel species.

• Tryland, Morten; Romano, Javier Sanchez; Nymo, Ingebjørg Helena; Breines, Eva Marie; Murguzur, Francisco Javier Ancin & Kjenstad, Ole Christian [Show all 8 contributors for this article] (2021). A Screening for Virus Infections in Eight Herds of Semi-domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Norway, 2013–2018. Frontiers in Veterinary Science. 8, p. 1–12. doi: 10.3389/fvets.2021.707787. Full text in Research Archive Show summary

  Background: Previous serological screenings have indicated that Eurasian semi-domesticated tundra reindeer (Rangifer tarandus tarandus) in Finnmark, Northern Norway, are exposed to alphaherpesvirus, gammaherpesvirus and pestivirus. Alphaherpesvirus (i.e., Cervid herpesvirus 2; CvHV2) has been identified as the transmissible component of infectious keratoconjunctivitis (IKC). Limited knowledge exists on the presence and prevalence of virus infections in other herding regions in Norway, which are hosting ~67,000 semi-domesticated reindeer and have contact with other species and populations of wildlife and livestock than those present in Finnmark.<p> <p>Methods: Blood samples (n = 618) were obtained over five winter seasons (2013–2018), from eight different herds representing summer pasture districts in Tana, Lakselv, Tromsø, Lødingen, Hattfjelldal, Fosen, Røros, and Filefjell, distributed from North to South of the reindeer herding regions in Norway. Blood samples were investigated for specific antibodies against five viral pathogen groups, alphaherpesvirus, gammaherpesvirus (viruses in the malignant catarrhal fever group; MCFV), pestivirus, bluetongue virus (BTV), and Schmallenberg virus (SBV), by using commercial multispecies serological tests (ELISA). In addition, swab samples obtained from the nasal mucosal membrane from 486 reindeer were investigated by PCR for parapoxvirus-specific DNA.<p> <p>Results: Antibodies against aphaherpesvirus and MCFV were found in all eight herds, with a total prevalence of 42% (range 21–62%) and 11% (range 2–15%), respectively. Anti-Pestivirus antibodies were detected in five of eight herds, with a total prevalence of 19% (range 0–52%), with two of the herds having a particularly high seroprevalence. Antibodies against BTV or SBV were not detected in any of the animals. Parapoxvirus-specific DNA was detected in two animals representing two different herds in Finnmark.<p> <p>Conclusions: This study confirmed that alphaherpesvirus and MCFV are enzootic throughout the geographical reindeer herding regions in Norway, and that pestivirus is present in most of the herds, with varying seroprevalence. No exposure to BTV and SBV was evident. This study also indicated that semi-domesticated reindeer in Finnmark are exposed to parapoxvirus without disease outbreaks being reported from this region.

• Angelos, John A.; Clothier, Kristin A.; Agulto, Regina L.; Mandzyuk, Boguslav & Tryland, Morten (2021). Relatedness of type IV pilin PilA amongst geographically diverse Moraxella bovoculi isolated from cattle with infectious bovine keratoconjunctivitis. Journal of Medical Microbiology. ISSN 0022-2615. 70(2). doi: 10.1099/JMM.0.001293. Full text in Research Archive Show summary

  Introduction. Moraxella bovoculi is frequently isolated from the eyes of cattle with infectious bovine keratoconjunctivitis (IBK; pinkeye). As with M. bovis, which has been causally linked to IBK, M. bovoculi expresses an RTX (repeats in the structural toxin) cytotoxin that is related to M. bovis cytotoxin. Pilin, another pathogenic factor in M. bovis, is required for corneal attachment. Seven antigenically distinct pilin serogroups have been described in M. bovis.<p> <p>Hypothesis/Gap Statement. Multiple different serogroups exist amongst type IV pilin encoded by M. bovis, however, it is not known whether M. bovoculi exhibits a similar degree of diversity in type IV pilin that it encodes.<p> <p>Aim. This study was done to characterize a structural pilin (PilA) encoded by M. bovoculi isolated from cases of IBK to determine if diversity exists amongst PilA sequences.<p> <p>Methodology. Ninety-four isolates of M. bovoculi collected between 2002 and 2017 from 23 counties throughout California and from five counties in four other Western states were evaluated.<p> <p>Results. DNA sequencing and determination of deduced amino acid sequences revealed ten (designated groups A through J) unique PilA sequences that were ~96.1–99.3%identical. Pilin groups A and C matched previously reported putative PilA sequences from M. bovoculi isolated from IBK-affected cattle in the USA (Virginia, Nebraska, and Kansas) and Asia (Kazakhstan). The ten pilin sequences identified were only ~74–76%identical to deduced amino acid sequences of putative pilin proteins identified from the previously reported whole-genome sequences of M. bovoculi derived from deep nasopharyngeal swabs of IBK-asymptomatic cattle.<p> <p>Conclusions. Compared to the diversity reported between structural pilin proteins amongst different serogroups of M. bovis, M. bovoculi PilA from geographically diverse isolates derived from IBK-affected cattle are more conserved.

• Tryland, Morten; Josefsen, Terje D.; Romano, Javier Sanchez; Marcin, Nina; Mørk, Torill & Arnemo, Jon M. (2021). Case Report: Subclinical Verminous Pneumonia and High Ambient Temperatures Had Severe Impact on the Anesthesia of Semi-domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) With Medetomidine–Ketamine. Frontiers in Veterinary Science. 8, p. 1–7. doi: 10.3389/fvets.2021.606323. Full text in Research Archive Show summary

  Semidomesticated Eurasian tundra reindeer (Rangifer tarandus tarandus, n = 21) were scheduled twice for chemical immobilization with medetomidine–ketamine as part of a scientific experiment in June 2014. During the first round of immobilizations, seven animals developed severe respiratory depression (RD). Three individuals died, and 4 recovered. The ambient temperature during the 2 days of immobilization (June 3 and 4) was high (mean 13.9–17.6°C) compared to the normal mean temperature for these 2 days (7–8°C) based on statistical records. During the second round of immobilizations, using the same anesthetic protocol for the remaining animals as in the first round but conducted under cooler conditions (mean 6.6°C for the period June 9–18), no signs of RD were observed. Clinical and pathological investigations indicated that the animals suffered from circulatory changes possibly caused by high ambient temperatures and granulomatous interstitial pneumonia due to Elaphostrongylus rangiferi larvae. These conditions, together with the cardiovascular effects of medetomidine, were likely causes of RD and the fatal outcome. We conclude that chemical immobilization of reindeer with medetomidine–ketamine should be avoided in May–June due to the potential risk when animals partly in winter coats encounter rising ambient temperatures and usually have parasites developing in their airways.

• Urbani, Lorenza; Tryland, Morten; Ehrich, Dorothee; Fuglei, Eva; Battilani, Mara & Balboni, Andrea (2020). Ancient origin and genetic segregation of canine circovirus infecting arctic foxes (Vulpes lagopus) in Svalbard and red foxes (Vulpes vulpes) in Northern Norway. Transboundary and Emerging Diseases. ISSN 1865-1674. 00, p. 1–11. doi: 10.1111/tbed.13783. Full text in Research Archive Show summary

  Canine circovirus (CanineCV) is a relatively new viral species, belonging to the family <i>Circoviridae</i>, whose pathogenic role is still uncertain. Since its first description in one domestic dog in 2011 from the USA, several reports have been documenting its distribution worldwide. Recently, CanineCV was also detected in wild animals such as wolves, foxes and badgers. In order to investigate the presence and the genetic characteristics of CanineCV in foxes of Arctic and Sub‐Arctic regions, the presence of CanineCV DNA in internal organs (liver and spleen) of 51 arctic foxes (<i>Vulpes lagopus</i>) from Svalbard archipelago and 59 red foxes (<i>Vulpes vulpes</i>) from Northern Norway, sampled from 1996 to 2001 and from 2014 to 2018, respectively, was screened by real‐time PCR. CanineCV was detected in 11/51 arctic foxes and in 10/59 red foxes, backdating the circulation of the virus at least to 1996 in the arctic fox population. The complete genome of 14 identified CanineCV was sequenced and analysed showing an identity higher than 80.8% with the reference strains available to date. According to the species demarcation threshold of 80% genome‐wide nucleotide sequence identity for members of the family <i>Circoviridae</i> provided by International Committee on Taxonomy of Viruses (ICTV), all the CanineCV belong to a single species. Phylogenetic analysis revealed that all the CanineCV were subdivided into five main clusters with one including only CanineCV identified in foxes. Furthermore, CanineCV identified in arctic foxes and red foxes formed two distinct lineages. From these data, we hypothesize that the viral transmission did not occur between the two species of foxes as a consequence of the lack of contact between the two hosts or that the virus acquired mutations in the time elapsed between the samplings.

• Egido, Sandra Núnez; Lowther, Andrew; Nymo, Ingebjørg Helena; Klein, Jörn; Breines, Eva Marie & Tryland, Morten (2020). Pathogen surveillance in Southern Ocean pinnipeds. Polar Research. ISSN 0800-0395. 39, p. 1–11. doi: 10.33265/polar.v39.3841. Full text in Research Archive Show summary

  Knowledge of the health status and potential effect of disease outbreaks among Southern Ocean fauna may be decisive for its conservation. We assessed the exposure and infection of Antarctic fur seals (Arctocephalus gazella, AFS) and Southern elephant seals (Mirounga leonine, SES) to parapoxvirus, Phocid alphaherpesvirus-1 (PhHV-1), smooth Brucella spp. and Toxoplasma gon-dii. AFS (n = 65) serum and swab samples, and SES (n = 13) serum samples from the sub- Antarctic island of Bouvetøya (54°25’S, 03°22’E) were collected during two austral summers (2014/15, 2017/18). Three polymerase chain reaction (PCR) tests amplifying the DNA polymerase, B2L and GIF parapoxvi-rus genomic regions were performed, investigating DNA from mucosal swab samples. The glycoprotein B gene was targeted to detect PhHV-1 viral DNA. Sera were assayed for T. gondii and smooth Brucella spp. antibodies with indi-rect enzyme-linked immunosorbent assays. Parapoxvirus PCR amplicons of the expected size were generated in two of the 29 AFS pups (nasal swabs, 2014/15), targeting the B2L (n = 2) and DNA polymerase (n = 1) genes, whereas the GIF PCR did not amplify target sequences. The PCR amplicons were sequenced and blasted in GenBank, revealing highest similarity with a seal parapoxvirus, confirming the presence of the virus in AFS for the first time. No PhHV-1 amplicons were generated, and antibodies against T. gondii or smooth Brucella spp. were not detected. Our data indicate that these seals are host for parapoxvirus but are neither exposed to smooth Brucella spp. nor T. gondii. Evidence of PhHV-1 shedding was not detected .

• Rode, Karyn D.; Obbard, Martyn; Belikov, Stanislav; Derocher, Andrew E.; Durner, George M. & Thiemann, Gregory W. [Show all 13 contributors for this article] (2020). Polar Bear (Ursus maritimus). In Penteriani, Vincenzo & Melletti, Mario (Ed.), Bears of the World. Ecology, conservation and management. Cambridge University Press. ISSN 9781108692571. p. 196–212. doi: 10.1017/9781108692571.015. Full text in Research Archive
• Romano, Javier Sanchez; Sørensen, Karen Kristine; Larsen, Anett Kristin; Mørk, Torill & Tryland, Morten (2020). Ocular Histopathological Findings in Semi-Domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) with Infectious Keratoconjunctivitis after Experimental Inoculation with Cervid Herpesvirus 2. Viruses. 12(9). doi: 10.3390/v12091007. Full text in Research Archive Show summary

  Infectious keratoconjunctivitis (IKC) is a common transmissible ocular disease in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus). In large outbreaks, IKC may affect tens of animals in a herd, with the most severe cases often requiring euthanasia due to the destruction of the affected eyes and permanent blindness. An experimental inoculation with cervid herpesvirus 2 (CvHV2), alone or in combination with Moraxella bovoculi, demonstrated that CvHV2 has the ability to cause clinical signs of IKC in previously unexposed reindeer. Tissues collected from upper and lower eyelids, lacrimal gland and cornea, were processed for light and transmission electron microscopy. Histopathological analysis of the eyes inoculated with CvHV2 showed widespread and severe pathological findings. Mucosal tissues from these eyes showed fibrinous and purulent exudates, hyperemia, hemorrhages, necrosis, vascular thrombosis, vascular necrosis, infiltration of mononuclear cells and neutrophils, and lymphoid follicle reaction, which matches the described histopathology of IKC in reindeer. Characteristic alpha-herpesvirus particles matching the size and morphology of CvHV2 were identified by transmission electron microscopy in the conjunctival tissue. The quantification of viral particles by qPCR revealed high copy numbers of viral DNA in all CvHV2 inoculated eyes, but also in the non-inoculated eyes of the same animals. The histopathology of eye tissues obtained from the CvHV2 inoculated reindeer and the lack of inflammation from bacterial infection, together with the detection of CvHV2 DNA in swabs from the inoculated and non-inoculated eyes of the same animals, verified that CvHV2 was the primary cause of the observed histopathological changes.

• Riseth, Jan Åge; Tømmervik, Hans & Tryland, Morten (2020). Spreading or gathering? Can traditional knowledge be a resource to tackle reindeer diseases associated with climate change? International Journal of Environmental Research and Public Health (IJERPH). ISSN 1661-7827. 17(16). doi: 10.3390/ijerph17166002. Full text in Research Archive Show summary

  This paper inquires whether reindeer herders’ traditional knowledge (TK) provides a reservoir of precaution and adaptation possibilities that may be relevant to counteract climate change. As our core example, we used the milking of reindeer—which, in some areas, was practiced up until the 1950s–1960s—and the risk of getting foot rot disease (digital necrobacillosis; slubbo in North Sámi), caused by the bacterium Fusobacterium necrophorum. Via wounds or scratches, the bacterium creates an infection that makes the infected limb swell and, eventually, necrotize. The disease is often mortal in its final stage. Historically, female reindeer were gathered on unfenced milking meadows near herder tents or in small corrals, from early summer onward. When the soil was wet and muddy, the risk of developing digital necrobacillosis was considerable. Our sources included classical Sámi author/herder narratives, ethnographic and veterinary literature, and herder interviews. For this study, we conducted a qualitative review of the literature and carried out individual in-depth interviews with local knowledge holders. Our findings seem consistent: a documented prevention strategy was, in early summer, to move the reindeer to unused grazing land and to avoid staying too long in trampled and dirty grazing land. Contemporary climate change and winter uncertainty due to freeze–thaw cycles and ice-locked pastures challenge this type of strategy. Due to a lack of pasture resources, typical actions today include the increased use of supplementary feeding, which involves more gathering and handling of reindeer, higher animal density, challenging hygienic conditions, and stress, which all contribute to increased risks of contracting and transmitting diseases.

• Neves, Carlos G Das; Yague, Carlos Sacristan; Madslien, Knut Ivar Engesæter & Tryland, Morten (2020). Gammaherpesvirus in cervid species from Norway: Characterization of a new virus in wild and semi-domesticated eurasian tundra reindeer (rangifer tarandus tarandus). Viruses. 12(8). doi: 10.3390/v12080876. Full text in Research Archive Show summary

  Gammaherpesvirus infections have been described in cervids worldwide, mainly the genera Macavirus or Rhadinovirus. However, little is known about the gammaherpesviruses species infecting cervids in Norway and Fennoscandia. Blood samples from semi-domesticated (n = 39) and wild (n = 35) Eurasian tundra reindeer (Rangifer tarandus tarandus), moose (Alces alces, n = 51), and red deer (Cervus elaphus, n = 41) were tested using a panherpesvirus DNA polymerase (DPOL) PCR. DPOL-PCR-positive samples were subsequently tested for the presence of glycoprotein B (gB) gene. The viral DPOL gene was amplified in 28.2% (11/39) of the semi-domesticated reindeer and in 48.6% (17/35) of the wild reindeer. All moose and red deer tested negative. Additionally, gB gene was amplified in 4 of 11 semi-domesticated and 15 of 17 wild Eurasian reindeer DPOL-PCR-positive samples. All the obtained DPOL and gB sequences were highly similar among them, and corresponded to a novel gammaherpesvirus species, tentatively named Rangiferine gammaherpesvirus 1, that seemed to belong to a genus different from Macavirus and Rhadinovirus. This is the first report of a likely host-specific gammaherpesvirus in semi-domesticated reindeer, an economic and cultural important animal, and in wild tundra reindeer, the lastpopulation in Europe. Future studies are required to clarify the potential impact of this gammaherpesvirus on reindeer health

• Scotter, Sophie Ellen; Tryland, Morten; Nymo, Ingebjørg Helena; Hanssen, Linda; Harju, Mikael & Lydersen, Christian [Show all 10 contributors for this article] (2019). Contaminants in Atlantic walruses in Svalbard Part 1: Relationships between exposure, diet and pathogen prevalence. Environmental Pollution (1987). ISSN 0269-7491. 244, p. 9–18. doi: 10.1016/j.envpol.2018.10.001. Full text in Research Archive Show summary

  This study investigated relationships between organohalogen compound (OHC) exposure, feeding habits, and pathogen exposure in a recovering population of Atlantic walruses (Odobenus rosmarus rosmarus) from the Svalbard Archipelago, Norway. Various samples were collected from 39 free-living, apparently healthy, adult male walruses immobilised at three sampling locations during the summers of 2014 and 2015. Concentrations of lipophilic compounds (polychlorinated biphenyls, organochlorine pesticides and polybrominated diphenyl ethers) were analysed in blubber samples, and concentrations of perfluoroalkylated substances (PFASs) were determined in plasma samples. Stable isotopes of carbon and nitrogen were measured in seven tissue types and surveys for three infectious pathogens were conducted. Despite an overall decline in lipophilic compound concentrations since this population was last studied (2006), the contaminant pattern was similar, including extremely large inter-individual variation. Stable isotope ratios of carbon and nitrogen showed that the variation in OHC concentrations could not be explained by some walruses consuming higher trophic level diets, since all animals were found to feed at a similar trophic level. Antibodies against the bacteria Brucella spp. and the parasite Toxoplasma gondii were detected in 26% and 15% of the walruses, respectively. Given the absence of seal-predation, T. gondii exposure likely took place via the consumption of contaminated bivalves. The source of exposure to Brucella spp. in walruses is still unknown. Parapoxvirus DNA was detected in a single individual, representing the first documented evidence of parapoxvirus in wild walruses. Antibody prevalence was not related to contaminant exposure. Despite this, dynamic relationships between diet composition, contaminant bioaccumulation and pathogen exposure warrant continuing attention given the likelihood of climate change induced habitat and food web changes, and consequently OHC exposure, for Svalbard walruses in the coming decades.

• Carlsson, Anja M.; Curry, Patricia S.; Elkin, Brett T.; Russell, Donald E.; Veitch, Alasdair M. & Branigan, Marsha [Show all 14 contributors for this article] (2019). Multi-pathogen serological survey of migratory caribou herds: A snapshot in time. PLOS ONE. 14(7). doi: 10.1371/journal.pone.0219838. Full text in Research Archive Show summary

  Pathogens can impact host survival, fecundity, and population dynamics even when no obvious disease is observed. Few baseline data on pathogen prevalence and diversity of caribou are available, which hampers our ability to track changes over time and evaluate impacts on caribou health. Archived blood samples collected from ten migratory caribou herds in Canada and two in Greenland were used to test for exposure to pathogens that have the potential to effect population productivity, are zoonotic or are emerging. Relationships between seroprevalence and individual, population, and other health parameters were also examined. For adult caribou, the highest overall seroprevalence was for alphaherpesvirus (49%, n = 722), pestivirus (49%, n = 572) and <i>Neospora caninum</i> (27%, n = 452). Lower seroprevalence was found for parainfluenza virus type 3 (9%, n = 708), <i>Brucella suis</i> (2%, n = 758), and <i>Toxoplasma gondii</i> (2%, n = 706). No animal tested positive for antibodies against West Nile virus (n = 418) or bovine respiratory syncytial virus (n = 417). This extensive multi-pathogen survey of migratory caribou herds provides evidence that caribou are exposed to pathogens that may have impacts on herd health and revealed potential interactions between pathogens as well as geographical differences in pathogen exposure that could be linked to the bio-geographical history of caribou. Caribou are a keystone species and the socio-economic cornerstone of many indigenous cultures across the North. The results from this study highlight the urgent need for a better understanding of pathogen diversity and the impact of pathogens on caribou health.

• Romano, Javier Sanchez; Leijon, Mikael; Hagström, Åsa; Jinnerot, Tomas; Rockström, Urlika & Tryland, Morten (2019). Chlamydia pecorum associated with an outbreak of infectious keratoconjunctivitis in semi-domesticated reindeer in Sweden. Frontiers in Veterinary Science. 6(14). doi: 10.3389/fvets.2019.00014. Full text in Research Archive Show summary

  Infectious keratoconjunctivitis (IKC), the most common ocular disease in ruminants worldwide, has affected semi-domesticated Eurasian reindeer (<i>Rangifer tarandus tarandus</i>) for over 100 years, both as individual cases and in outbreaks affecting tens to hundreds of animals. Recurrent IKC outbreaks have been affecting a semi-domesticated reindeer herd in Östra Kikkejaure (Norrbotten county, Sweden) from 2014. The latest episode of these recurrent outbreaks, in winter 2016/2017, was investigated in this study. Clinical findings were in line with previous reports of IKC in semi-domesticated reindeer and the clinical signs displayed by the affected animals (<i>n</i> = 30) included increased lacrimation, follicular conjunctivitis, purulent secretions around the affected eyes and corneal edema. Laboratory analyses of the samples revealed the presence of <i>Chlamydiaceae</i> in most samples obtained from the clinically affected animals (98.3%, <i>n</i> = 60), but also a high seroprevalence of cervid herpesvirus 2 (CvHV2) antibodies (56.6%, <i>n</i> = 53). <i>Moraxella bovoculi</i> was isolated from nine IKC-affected animals during the outbreak (45.0%, <i>n</i> = 20). All affected animals were treated with long-acting antibiotics and recovered from the disease, testing negative for the presence of <i>Chlamydiaceae</i> DNA by PCR 16 days and 3 months after the initial treatment. For the first time, <i>Chlamydia pecorum</i> was identified in semi-domesticated reindeer, and the involvement of <i>Chlamydiaceae</i> in a clinical outbreak of IKC is reported. The CvHV2 seroprevalence (56.6%) and the data obtained from a previous outbreak in 2014 also suggest the involvement of the reindeer alphaherpesvirus in the recurrent outbreaks.

• Tomaselli, Matilde; Elkin, Brett T.; Kutz, Susan; Harms, Naomi Jane; Nymo, Ingebjørg Helena & Davison, Tracy [Show all 11 contributors for this article] (2019). A transdisciplinary approach to Brucella in Muskoxen of the Western Canadian Arctic 1989-2016. EcoHealth. ISSN 1612-9202. 16, p. 488–501. doi: 10.1007/s10393-019-01433-3. Full text in Research Archive Show summary

  Brucella serostatus was evaluated in 3189 muskoxen sampled between 1989 and 2016 from various locations of the Canadian Arctic archipelago and mainland, near the communities of Sachs Harbour and Ulukhaktok, Northwest Territories, and Cambridge Bay and Kugluktuk, Nunavut. Brucella antibodies were found only in muskoxen sampled around Cambridge Bay, both on southern Victoria Island and on the adjacent mainland (Kent Peninsula). Consistent with participatory epidemiology data documented from local harvesters describing increased Brucella-like syndromes (swollen joints and lameness) and a decreased proportion of juveniles, the apparent Brucella seroprevalence in the sampled muskoxen of the Cambridge Bay area increased from 0.9% (95% CI 0.3–2.1) in the period of 1989–2001 to 5.6% (95% CI 3.3–8.9) in 2010–2016. The zoonotic bacteria Brucella suis biovar 4 was also cultured from tissues of muskoxen sampled on Victoria Island near Ulukhaktok in 1996 (n = 1) and Cambridge Bay in 1998, 2014, and 2016 (n = 3). Overall, our data demonstrate that B. suis biovar 4 is found in muskoxen that are harvested for food and by guided hunts on Victoria Island and Kent Peninsula, adding an important public health dimension to this study. Robust participatory epidemiology data on muskox health and diseases greatly enhanced the interpretation of our Cambridge Bay data and, combined with the serological and microbiological data, provide compelling evidence that the prevalence of B. suis biovar 4 has increased in this area since the late 1990s. This study enhances the available knowledge on Brucella exposure and infection in muskoxen and provides an example of how scientific knowledge and local knowledge can work together to better understand disease status in wildlife.

• Balboni, Andrea; Tryland, Morten; Mørk, Torill; Killengreen, Siw Turid; Fuglei, Eva & Battilani, Mara (2019). Unique genetic features of canine adenovirus type 1 (CAdV-1) infecting red foxes (Vulpes vulpes) in northern Norway and arctic foxes (Vulpes lagopus) in Svalbard. Veterinary research communications. ISSN 0165-7380. 43(2), p. 67–76. doi: 10.1007/s11259-019-09746-y. Full text in Research Archive Show summary

  Canine adenovirus type 1 (CAdV-1) is the aetiological agent of infectious canine hepatitis (ICH) in domestic dogs (<i>Canis familiaris</i>). In spite of the widespread use of vaccination, CAdV-1 continues to circulate in the dog population. Although a high number of serological screenings have indicated that CAdV-1 is widespread in fox species, little is known about the potential role of foxes as reservoirs of CAdV-1. Furthermore, very little data exist on the molecular features of this virus in foxes. To add to existing knowledge on CAdV-1 circulating in wild carnivores, tissue samples from CAdV-seropositive red foxes (<i>Vulpes vulpes, n</i> = 10) from the northern mainland of Norway and arctic foxes (<i>Vulpes lagopus,</i> n = 10) from the Svalbard archipelago, Norway, were investigated using a molecular approach to detect CAdV-1 DNA and important structural and non-structural genes of the detected viruses were sequenced and analysed. Amplicons characteristic for CAdV-1 were amplified from 14 out of 20 foxes (7 red foxes and 7 arctic foxes) and spleen and lymph node tissues resulted optimal targets for the viral DNA detection. The nucleotide sequences showed unique features that distinguished the viruses detected in this study from the CAdV-1 to date identified in wild carnivores and dogs. Greater attention should be given to genetically different CAdV-1 circulating in wild carnivores that may be transferred to dogs, potentially causing disease and reducing the effectiveness of available vaccines.

• Nymo, Ingebjørg Helena; Davidson, Rebecca K.; Gilhuus, Marianne; Holmgren, Karin Elisabeth; Mørk, Torill & Lian, Hans [Show all 10 contributors for this article] (2019). Egglederbetennelse hos Svalbardryper i fangenskap. Norsk veterinærtidsskrift. ISSN 0332-5741. 131(7), p. 444–445. Full text in Research Archive
• Tryland, Morten; Nymo, Ingebjørg Helena; Romano, Javier Sanchez; Mørk, Torill; Klein, Joern & Rockström, Ulrika (2019). Infectious Disease Outbreak Associated with Supplementary Feeding of Semi-Domesticated Reindeer. Frontiers in Veterinary Science. 6. doi: 10.3389/fvets.2019.00126. Full text in Research Archive Show summary

  Supplementary winter feeding of semi-domesticated reindeer (Rangifer tarandus tarandus) has become more common in Sweden and Norway due to reindeer pasture fragmentation and climatic conditions. With increased corralling and feeding, often associated with animal stress, increased animal-to-animal contact, and poor hygienic conditions, an altered range of health challenges and diseases may emerge. An outbreak of three different infectious diseases appeared simultaneously in a reindeer herd in Norrbotten County, Sweden. The animals were corralled and fed silage. Several animals in poor body condition stopped eating, with drool and discoloration of the hair coat around the mouth. There were large, black, necrotic lesions on the tongue and gingiva, with holes perforating the chin, indicative of oral necrobacillosis and Fusobacterium spp. infection. Simultaneously, animals were seen with proliferative lesions in the oral mucosa and on the lips, characteristic of contagious ecthyma and Orf virus infection. Furthermore, three animals had keratoconjunctivitis suggesting exposure to cervid herpesvirus 2 (CvHV2) and possibly secondary bacterial infections. DNA specific for Fusobacterium necrophorum and ORFV was detected in relevant tissue samples. Antibodies against CvHV2 were detected in 10 of 13 diseased and in four of 11 apparently healthy reindeer. Nine animals were found dead or were euthanized during the outbreak. Health risk factors associated with feeding and corralling may severely impact animal welfare and the herder’s economy, andmay represent an underestimated cost when replacing natural grazing with feeding.

• Omazic, Anna; Aurosell, Caroline; Fedorov, Valery; Hagström, Åsa; Kantanen, Juha & Leijon, Mikael [Show all 17 contributors for this article] (2019). Seroprevalence of pestivirus in Eurasian tundra reindeer in Finland, Sweden, Norway, Iceland and Russian Federation. Infection Ecology & Epidemiology. 9(1), p. 1–9. doi: 10.1080/20008686.2019.1682223. Full text in Research Archive Show summary

  Reindeer herding is of great importance for the indigenous people of the Fennoscandia peninsula and northern Russia. There are also free-ranging feral populations of reindeer in Finland, Iceland, Norway and Russian Federation. The genus Pestivirus contains several viral species that infect ungulates and often show capacity to transmit between different host species. Sera from 520 Eurasian tundra reindeer (Rangifer tarandus tarandus) from Finland, Sweden, Norway, Iceland and Russian Federation were analysed and the prevalence of pestivirus-specific antibodies was determined. Seropositivity proportion was 48.5% for Sweden and 41.2% for Norway, but only 1.6% for Iceland and 2.5% for Finland. All Russian reindeer investigated were seronegative. Pan-pestivirus RT-PCR of seronegative animals (n = 156) from seropositive herds confirmed their negative status. These results indicate unexpectedly non-uniform circulation of an as yet uncharacterised pestivirus in Eurasian reindeer populations. The high seroprevalence in some regions warrants further studies of pestivirus infection dynamics, effects on reindeer health and population dynamics.

• Romano, Javier Sanchez; Grund, Lisa; Obiegala, Anna; Nymo, Ingebjørg Helena; Murguzur, Francisco Javier Ancin & Li, Hong [Show all 9 contributors for this article] (2019). A Multi-Pathogen Screening of Captive Reindeer (Rangifer tarandus) in Germany Based on Serological and Molecular Assays. Frontiers in Veterinary Science. 6. doi: 10.3389/fvets.2019.00461. Full text in Research Archive Show summary

  Captive reindeer in German zoos and wildlife parks live outside their natural geographic range and are exposed to a variety of viral, bacterial and protozoan pathogens, some host-specific and some which they are not exposed to in their native habitat. Reindeer blood samples and ticks collected in 2013 from 123 reindeer at 16 different zoological facilities were available from a previous study. The aims of this study were to assess the serological status of these animals with regards to various microorganisms as well as to test ticks (<i>Ixodes ricinus</i>) and blood samples for the presence of <i>Anaplasma</i> spp. DNA in order to evaluate the exposure of captive reindeer in Germany to a variety of pathogens. A total of 119 or 118 serum samples were screened (ELISA) and antibodies were detected (seropositive/tested, prevalence, confidence interval) against alphaherpesvirus (24/119, 20.3%, CI: 13.9–28.3), bluetongue virus (BTV; 4/119, 3.4%, CI: 1.0–8.7), malignant catarrhal fever related gammaherpesvirus (MCFV-related gammaherpesvirus; 7/119, 5.9%, CI: 2.7–11.9), pestivirus (5/118, 4.2%, CI: 1.6–9.8), Schmallenberg virus (SBV; 70/118, 59.3%, CI: 50.3–67.8), smooth <i>Brucella</i> spp. (1/118; 0.9%, CI: 0–5.1), <i>Neospora caninum</i> (5/118, 4.2%, CI: 1.6–9.8), and <i>Toxoplasma gondii</i> (62/119, 52.1%, CI: 43.2–60.9). These results suggested the exposure of reindeer to all tested pathogens. Moreover, real-time PCR for <i>Anaplasma phagocytophilum</i> targeting the partial <i>msp2</i> gene was performed on DNA extracted from whole blood samples from reindeer (<i>n</i> = 123) and from ticks (<i>n</i> = 49) collected from 22 reindeer in seven different facilities. In addition to the real-time PCR, a semi-nested PCR for the partial <i>groEL</i> gene, and a nested PCR targeting the partial 16S rRNA gene were performed. DNA of <i>A. phagocytophilum</i> was detected in 17 reindeer (13.8%) and 15 ticks (30.6%). Three of the five reindeer with ticks having <i>A. phagocytophilum</i> DNA also had such DNA in blood. These results indicate that captive reindeer can be exposed to several ruminant pathogens that they hitherto had no known exposure to through their natural geographical distribution and habitats as shown for <i>Culicoides</i>-borne BTV and SBV. Further, captive reindeer may serve as reservoir hosts for pathogens circulating in local domestic, captive, and wild ruminant species and populations and arthropod vectors.

• Bondo, Kristin; Macbeth, Bryan J.; Schwantje, Helen; Orsel, Karin; Culling, Diane & Culling, Brad [Show all 9 contributors for this article] (2019). HEALTH SURVEY OF BOREAL CARIBOU (RANGIFER TARANDUS CARIBOU) IN NORTHEASTERN BRITISH COLUMBIA, CANADA. Journal of Wildlife Diseases. ISSN 0090-3558. 55(3), p. 544–562. doi: 10.7589/2018-01-018. Full text in Research Archive Show summary

  ABSTRACT: Boreal woodland caribou (Rangifer tarandus caribou) are listed as threatened across Canada, and a basic understanding of their health status is lacking. From December 2012 to April 2013, we investigated multiple health indices for adult female boreal caribou (n1⁄4163) captured from seven herds in NE British Columbia, Canada. Health indices included physical characteristics, physiologic and trace mineral status, exposure to or infection with selected pathogens, and measures of chronic stress and inflammation, including serum amyloid A, haptoglobin, and hair cortisol concentration. Key findings were exposure to the bacterium Erysipelothrix rhusiopathiae in 14% of individuals, mild to severe hair loss associated with winter tick (Dermacentor albipictus) infestations in 76% of caribou from December to early February and 81% from late February to early April, and evidence of trace mineral deficiencies with 99% and 34% of individuals deficient in copper and selenium, respectively. Seroprevalence for exposure to selected pathogens was: alphaherpesvirus (63%), pestivirus (1%), Besnoitia spp. (60%), and Neospora caninum (2%). All animals were seronegative to Brucella spp. and Toxoplasma gondii. Mycobacterium avium ssp. paratuberculosis was not detected in any fecal samples. Parasite eggs or larvae, including Parelaphostrongylus andersoni (36%), Skrjabinema spp. (1%), Strongyle-type eggs (11%), Moniezia-type eggs (8%), and nematodirines (3%), were detected on fecal examination, but at low intensity. Blood biochemistry values and hair cortisol concentrations were within ranges previously reported in Rangifer tarandus sspp. Some significant differences among herds were noted, including antler morphology, exposure to Besnoitia spp., and concentrations of serum amyloid A, copper, cobalt, manganese, and iron.

• Neves, Carlos G Das; Wensman, Johan Johansson; Nymo, Ingebjørg Helena; Skjerve, Eystein; Alenius, Stefan & Tryland, Morten (2019). Pestivirus infections in semi domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus): A retrospective cross-sectional serological study in Finnmark county, Norway. Viruses. 12(1), p. 1–12. doi: 10.3390/v12010029. Full text in Research Archive Show summary

  Members of the Pestivirus genus (family <i>Flaviviridae</i>) cause severe and economically important diseases in livestock. Serological studies have revealed the presence of pestiviruses in different cervid species, including wild and semi-domesticated Eurasian tundra reindeer. In this retrospective study, serum samples collected between 2006 and 2008 from 3339 semi-domesticated Eurasian reindeer from Finnmark County, Norway, were tested for anti-pestivirus antibodies using an enzyme linked immunosorbent assay (ELISA) and a subset of these by virus neutralization test (VNT). A seroprevalence of 12.5% was found, varying from 0% to 45% among different herding districts, and 20% in western Finnmark, as compared to 1.7% in eastern Finnmark. Seroprevalence increased with age. Pestivirus-specific RNA was not detected in any of the 225 serum samples tested by real-time RT-PCR. Based on VNT results, using a panel of one bovine viral diarrhea virus (BVDV) strain and two border disease virus (BDV) strains, the virus is most likely a reindeer-specific pestivirus closely related to BDV. A characterization of the causative virus and its pathogenic impact on reindeer populations, as well as its potential to infect other domestic and wild ruminants, should be further investigated

• Omazic, Anna; Bylund, Helena; Boqvist, Sofia; Hogberg, Anne-Marie; Björkman, Christer & Tryland, Morten [Show all 14 contributors for this article] (2019). Identifying climate-sensitive infectious diseases in animals and humans in Northern regions. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 61(1). doi: 10.1186/s13028-019-0490-0. Full text in Research Archive Show summary

  <i>Background</i> - General knowledge on climate change effects and adaptation strategies has increased significantly in recent years. However, there is still a substantial information gap regarding the influence of climate change on infectious diseases and how these diseases should be identified. From a One Health perspective, zoonotic infections are of particular concern. The climate in Northern regions is changing faster than the global average. This study sought to identify climate-sensitive infectious diseases (CSIs) of relevance for humans and/or animals living in Northern regions. Inclusion criteria for CSIs were constructed using expert assessments. Based on these principles, 37 potential CSIs relevant for Northern regions were identified. A systematic literature search was performed in three databases using an explicit stepwise approach to determine whether the literature supports selection of these 37 potential CSIs.<p> <p><i>Results</i> - In total, 1275 nominated abstracts were read and categorised using predefined criteria. Results showed that arthropod vector-borne diseases in particular are recognised as having potential to expand their distribution towards Northern latitudes and that tick-borne encephalitis and borreliosis, midge-borne bluetongue and the parasitic infection fasciolosis can be classified as climate-sensitive. Many of the other potential CSIs considered are affected by extreme weather events, but could not be clearly classified as climate-sensitive. An additional literature search comparing awareness of climate influences on potential CSIs between 1997–2006 and 2007–2016 showed an increase in the number of papers mentioning effects of climate change.<p> <p><i>Conclusions</i> - The four CSIs identified in this study could be targeted in a systematic surveillance programme in Northern regions. It is evident that climate change can affect the epidemiology and geographical range of many infectious diseases, but there were difficulties in identifying additional CSIs, most likely because other factors may be of equal or greater importance. However, climate-ecological dynamics are constantly under change, and therefore diseases may fall in or out of the climate-sensitive definition over time. There is increasing awareness in the literature of the effects of climate change on infectious diseases over time.

• Romano, Javier Sanchez; Mørk, Torill; Laaksonen, Sauli; Ågren, Erik; Nymo, Ingebjørg Helena & Sunde, Marianne [Show all 7 contributors for this article] (2018). Infectious keratoconjunctivitis in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus): Microbiological study of clinically affected and unaffected animals with special reference to cervid herpesvirus 2. BMC Veterinary Research. 14(15). doi: 10.1186/s12917-018-1338-y. Full text in Research Archive Show summary

  Background: Infectious keratoconjunctivitis (IKC) is one of the most common ocular diseases in ruminants worldwide. In addition to keratitis and conjunctivitis, animals with IKC can develop uveitis, corneal ulcer, and in severe cases, blindness. The bacteria Moraxella spp. has been described as the primary causative agent of infectious bovine keratoconjunctivitis (IBK) in cattle (Bos taurus), while Chlamydia spp. and Mycoplasma conjunctivae are considered the main causative agents of IKC in sheep (Ovis aries). Previous studies indicated cervid herpesvirus 2 (CvHV2) as the primary causative agent of IKC in semi-domesticated reindeer (Rangifer tarandus tarandus). The aim of the study was to investigate the presence and prevalence of potential pathogens for IKC in reindeer, and compare the ocular microbiota of animals with IKC, with apparently healthy animals. Results: Semi-domesticated reindeer (n = 341), with (n = 108) or without (n = 113) ocular clinical signs, or with no information on clinical status (n = 120), were sampled in Norway, Sweden and Finland in 2010–2014. Seroprevalence was 37.4% for alphaherpesvirus (95/254), 3.8% for gammaherpesvirus (8/211) and 7.1% for pestivirus (15/211) (ELISA). PCR analyses of conjunctival swab samples revealed a prevalence of 28.5% for CvHV2 (57/200), 11.9% for Chlamydiaceae (16/135) and 1.0% for M. conjunctivae (2/197). Bacteriological cultivation of 202 conjunctival swab samples revealed bacterial growth from 75.2% of the samples, with Moraxella spp. being isolated from 21.6% (11/51) of the animals with and 5.6% (5/84) without ocular clinical signs. A significant association (p < 0.001) existed between the presence of clinical signs of IKC and CvHV2 DNA in the affected eyes, an association that was not present for other microorganisms. Conclusions: These results support the hypothesis that CvHV2 is the primary agent of IKC in semi-domesticated reindeer in Fennoscandia, with Moraxella bovoculi being a secondary candidate, since it was isolated in two different outbreaks of IKC. Further studies should be carried out to better understand the infection biology and the pathogenesis of IKC in reindeer.

• Tryland, Morten; Balboni, Andrea; Killengreen, Siw Turid; Mørk, Torill; Nielsen, Ole & Yoccoz, Nigel Gilles [Show all 8 contributors for this article] (2018). A screening for canine distemper virus, canine adenovirus and carnivore protoparvoviruses in Arctic foxes (Vulpes lagopus) and red foxes (Vulpes vulpes) from Arctic and sub-Arctic regions of Norway. Polar Research. ISSN 0800-0395. 37(1). doi: 10.1080/17518369.2018.1498678. Full text in Research Archive Show summary

  Canine distemper virus (CDV), canine adenovirus (CAdV) and canine parvovirus type 2 (CPV-2) cause disease in dogs (Canis familiaris). These, or closely related viruses, may also infect wild carnivores. The aim of this study was to investigate exposure to CDV, CAdV and CPV-2 among fox populations in Norway. Arctic foxes (n = 178) from High-Arctic Svalbard were investigated for antibodies against CDV. Arctic foxes (n = 301) from Svalbard and red foxes from LowArctic (n = 326) and sub-Arctic (n = 74) regions in Finnmark County, Norway, were investigated for antibodies against CAdV and for the presence of carnivore protoparvovirus DNA in spleen and mesenteric lymph nodes using polymerase chain reaction. Seroprevalence against CDV in Arctic foxes decreased from 25% (1995/96) to 6% (2001/02), whereas the seroprevalence against CAdV increased from 25–40% during the seasons 1995/96 to 2001/02 to 68% for the last study year (2002/03). In red foxes, the seroprevalence against CAdV varied between 31% and 67% for the seasons 2004/05 to 2007/08, increasing to 80% for the last study year. Carnivore protoparvovirus DNA was not detected in any of the 301 Arctic foxes and the 265 red foxes investigated. These results show that CDV and CAdV are enzootic in the Arctic fox population (Svalbard), and that CAdV is enzootic in both the Low-Arctic and subArctic red fox populations (Finnmark). Further studies are needed to better understand the infection biology and the impact of CDV and CAdV in these fox populations, and if viruses may be shared between foxes and other carnivores, including dogs.

• Sonne, Christian; Andersen-Ranberg, Emilie; Rajala, Elisabeth; Agerholm, Jørgen S.; Bonefeld-Jørgensen, Eva & Desforges, Jean-Pierre [Show all 22 contributors for this article] (2018). Prevalence of antibodies against Brucella spp. in West Greenland polar bears (Ursus maritimus) and East Greenland muskoxen (Ovibos moschatus). Polar Biology. ISSN 0722-4060. 41(9), p. 1671–1680. doi: 10.1007/s00300-018-2307-4. Full text in Research Archive Show summary

  Zoonotic infections transmitted from terrestrial and marine mammals to humans in European Arctic are of unknown significance, despite considerable potential for transmission due to local hunt and a rapidly changing environment. As an example, infection with Brucella bacteria may have significant impact on human health due to consumption of raw meat or otherwise contact with tissues and fluids of infected game species such as muskoxen and polar bears. Here, we present serological results for Baffin Bay polar bears (Ursus maritimus) (n = 96) and North East Greenland muskoxen (Ovibos moschatus) (n = 32) for antibodies against Brucella spp. The analysis was a two-step trial initially using the Rose Bengal Test (RBT), followed by confirmative competitive enzyme-linked immunosorbent assays of RBT-positive samples. No muskoxen had antibodies against Brucella spp., while antibodies were detected in six polar bears (6.25%) rendering a seroprevalence in line with previous findings in other Arctic regions. Seropositivity was not related to sex, age or biometrics i.e. size and body condition. Whether Brucella spp. antibodies found in polar bears were due to either prey spill over or true recurrent Brucella spp. infections is unknown. Our results therefore highlight the importance of further research into the zoonotic aspects of Brucella spp. infections, and the impact on wildlife and human health in the Arctic region.

• Foster, Geoffrey; Nymo, Ingebjørg Helena; Kovacs, Kit M.; Beckmen, Kimberlee B.; Brownlow, Andrew C. & Baily, Johanna L. [Show all 14 contributors for this article] (2018). First isolation of Brucella pinnipedialis and detection of Brucella antibodies from bearded seals Erignathus barbatus. Diseases of Aquatic Organisms. ISSN 0177-5103. 128(1), p. 13–20. doi: 10.3354/dao03211. Full text in Research Archive Show summary

  Brucella species infecting marine mammals was first reported in 1994 and in the years since has been documented in various species of pinnipeds and cetaceans. While these reports have included species that inhabit Arctic waters, the few available studies on bearded seals Erignathus barbatus have failed to detect Brucella infection to date. We report the first isolation of Brucella pinnipedialis from a bearded seal. The isolate was recovered from the mesenteric lymph node of a bearded seal that stranded in Scotland and typed as ST24, a sequence type associated typically with pinnipeds. Furthermore, serological studies of free-ranging bearded seals in their native waters detected antibodies to Brucella in seals from the Chukchi Sea (1990−2011; 19%) and Svalbard (1995−2007; 8%), whereas no antibodies were detected in bearded seals from the Bering Sea or Bering Strait or from captive bearded seals.

• Tryland, Morten; Beckmen, Kimberlee B.; Burek-huntington, Kathleen; Breines, Eva Marie & Klein, Joern (2018). Orf virus infection in Alaskan mountain goats, Dall’s sheep, muskoxen, caribou and Sitka black-tailed deer. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 60(12). doi: 10.1186/s13028-018-0366-8. Full text in Research Archive Show summary

  Background: The zoonotic Orf virus (ORFV; genus Parapoxvirus, Poxviridae family) occurs worldwide and is transmit‑ted between sheep and goats, wildlife and man. Archived tissue samples from 16 Alaskan wildlife cases, representing mountain goat (Oreamnos americanus, n= 8), Dall’s sheep (Ovis dalli dalli, n= 3), muskox (Ovibos moschatus, n= 3), Sitka black‑tailed deer (Odocoileus hemionus sitkensis, n= 1) and caribou (Rangifer tarandus granti, n= 1), were analyzed.Results: Clinical signs and pathology were most severe in mountain goats, affecting most mucocutaneous regions, including palpebrae, nares, lips, anus, prepuce or vulva, as well as coronary bands. The proliferative masses were solid and nodular, covered by dark friable crusts. For Dall’s sheep lambs and juveniles, the gross lesions were similar to those of mountain goats, but not as extensive. The muskoxen displayed ulcerative lesions on the legs. The caribou had two ulcerative lesions on the upper lip, as well as lesions on the distal part of the legs, around the main and dew claws. A large hairless spherical mass, with the characteristics of a fibroma, was sampled from a Sitka black‑tailed deer, which did not show proliferative lesions typical of an ORFV infection. Polymerase chain reaction analyses for B2L, GIF, vIL‑10 and AT I demonstrated ORFV specific DNA in all cases. Sequences from Dall’s sheep formed a separate cluster, comparable to ORFV from domestic sheep. Sequences from the other species were different from the Dall’s sheep sequences, but almost identical to each other.Conclusions: This is the first major investigation of parapoxvirus infections in large Alaskan game species, and the first report of parapoxvirus infection in caribou and Sitka black‑tailed deer. This study shows that most of the wild ruminant species in Alaska and from most parts of Alaska, can carry and be affected by ORFV. These findings call for attention to transmission of ORFV from wildlife to livestock and to hunters, subsistence harvesters, and wildlife biologists.

• Sonne, Christian; Andersen-Ranberg, Emilie; Rajala, Elisabeth; Agerholm, Jørgen S.; Bonefeld-Jørgensen, Eva & Desforges, Jean-Pierre [Show all 18 contributors for this article] (2018). Seroprevalence for Brucella spp. in Baltic ringed seals (Phoca hispida) and East Greenland harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals. Veterinary Immunology and Immunopathology. ISSN 0165-2427. 198, p. 14–18. doi: 10.1016/j.vetimm.2018.02.005. Full text in Research Archive Show summary

  Zoonotic infections transmitted from marine mammals to humans in the Baltic and European Arctic are of unknown significance, despite given considerable potential for transmission due to local hunt. Here we present results of an initial screening for Brucella spp. in Arctic and Baltic seal species. Baltic ringed seals (Pusa hispida, n = 12) sampled in October 2015 and Greenland Sea harp seals (Pagophilus groenlandicus, n = 6) and hooded seals (Cystophora cristata, n = 3) sampled in March 2015 were serologically analysed for antibodies against Brucella spp. The serological analyses were performed using the Rose Bengal Test (RBT) followed by a confirmatory testing of RBT-positive samples by a competitive-enzyme linked immunosorbent assay (C-ELISA). Two of the Baltic ringed seals (a juvenile male and a juvenile female) were seropositive thus indicating previous exposure to a Brucella spp. The findings indicate that ringed seals in the Baltic ecosystem may be exposed to and possibly infected by Brucella spp. No seropositive individuals were detected among the Greenland harp and hooded seals. Although our initial screening shows a zoonotic hazard to Baltic locals, a more in-depth epidemiological investigation is needed in order to determine the human risk associated with this.

• Okoli, Arinze Stanley; Okeke, malachy ifeanyi; Tryland, Morten & Moens, Ugo (2018). CRISPR/Cas9—Advancing Orthopoxvirus Genome Editing for Vaccine and Vector Development. Viruses. 10(50), p. 1–27. doi: 10.3390/v10010050. Full text in Research Archive Show summary

  The clustered regularly interspaced short palindromic repeat (CRISPR)/associated protein 9 (Cas9) technology is revolutionizing genome editing approaches. Its high efficiency, specificity, versatility, flexibility, simplicity and low cost have made the CRISPR/Cas9 system preferable to other guided site-specific nuclease-based systems such as TALENs (Transcription Activator-like Effector Nucleases) and ZFNs (Zinc Finger Nucleases) in genome editing of viruses. CRISPR/Cas9 is presently being applied in constructing viral mutants, preventing virus infections, eradicating proviral DNA, and inhibiting viral replication in infected cells. The successful adaptation of CRISPR/Cas9 to editing the genome of Vaccinia virus paves the way for its application in editing other vaccine/vector-relevant orthopoxvirus (OPXV) strains. Thus, CRISPR/Cas9 can be used to resolve some of the major hindrances to the development of OPXV-based recombinant vaccines and vectors, including sub-optimal immunogenicity; transgene and genome instability; reversion of attenuation; potential of spread of transgenes to wildtype strains and close contacts, which are important biosafety and risk assessment considerations. In this article, we review the published literature on the application of CRISPR/Cas9 in virus genome editing and discuss the potentials of CRISPR/Cas9 in advancing OPXV-based recombinant vaccines and vectors. We also discuss the application of CRISPR/Cas9 in combating viruses of clinical relevance, the limitations of CRISPR/Cas9 and the current strategies to overcome them

• Nymo, Ingebjørg Helena; Rødven, Rolf; Beckmen, Kimberlee B.; Larsen, Anett Kristin; Tryland, Morten & Quakenbush, Lori [Show all 7 contributors for this article] (2018). Brucella antibodies in alaskan true seals and eared seals — two different stories. Frontiers in Veterinary Science. 5(8). doi: 10.3389/fvets.2018.00008. Full text in Research Archive Show summary

  Brucella pinnipedialis was first isolated from true seals in 1994 and from eared seals in 2008. Although few pathological findings have been associated with infection in true seals, reproductive pathology including abortions, and the isolation of the zoonotic strain type 27 have been documented in eared seals. In this study, a Brucella enzyme-linked immunosorbent assay (ELISA) and the Rose Bengal test (RBT) were initially compared for 206 serum samples and a discrepancy between the tests was found. Following removal of lipids from the serum samples, ELISA results were unaltered while the agreement between the tests was improved, indicating that serum lipids affected the initial RBT outcome. For the remaining screening, we used ELISA to investigate the presence of Brucella antibodies in sera of 231 eared and 1,412 true seals from Alaskan waters sampled between 1975 and 2011. In eared seals, Brucella antibodies were found in two Steller sea lions (Eumetopias jubatus) (2%) and none of the 107 Northern fur seals (Callorhinus ursinus). The low seroprevalence in eared seals indicate a low level of exposure or lack of susceptibility to infection. Alternatively, mortality due to the Brucella infection may remove seropositive animals from the population. Brucella antibodies were detected in all true seal species investigated; harbor seals (Phoca vitulina) (25%), spotted seals (Phoca largha) (19%), ribbon seals (Histriophoca fasciata) (16%), and ringed seals (Pusa hispida hispida) (14%). There was a low seroprevalence among pups, a higher seroprevalence among juveniles, and a subsequent decreasing probability of seropositivity with age in harbor seals. Similar patterns were present for the other true seal species; however, solid conclusions could not be made due to sample size. This pattern is in accordance with previous reports on B. pinnipedialis infections in true seals and may suggest environmental exposure to B. pinnipedialis at the juvenile stage, with a following clearance of infection. Furthermore, analyses by region showed minor differences in the probability of being seropositive for harbor seals from different regions regardless of the local seal population trend, signifying that the Brucella infection may not cause significant mortality in these populations. In conclusion, the Brucella infection pattern is very different for eared and true seals.

• Ricci, Antonia; Allende, Ana; Bolton, Declan; Chemaly, Marianne; Davies, Robert & Escamez, Pablo Salvador Fernandez [Show all 29 contributors for this article] (2018). Scientific opinion on chronic wasting disease (II). EFSA Journal. ISSN 1831-4732. 16(1). doi: 10.2903/j.efsa.2018.5132. Full text in Research Archive Show summary

  The European Commission asked EFSA for a scientific opinion on chronic wasting disease in two parts. Part one, on surveillance, animal health risk‐based measures and public health risks, was published in January 2017. This opinion (part two) addresses the remaining Terms of Reference, namely, ‘are the conclusions and recommendations in the EFSA opinion of June 2004 on diagnostic methods for chronic wasting disease still valid? If not, an update should be provided’, and ‘update the conclusions of the 2010 EFSA opinion on the results of the European Union survey on chronic wasting disease in cervids, as regards its occurrence in the cervid population in the European Union’. Data on the performance of authorised rapid tests in North America are not comprehensive, and are more limited than those available for the tests approved for statutory transmissible spongiform encephalopathies surveillance applications in cattle and sheep. There are no data directly comparing available rapid test performances in cervids. The experience in Norway shows that the Bio‐Rad TeSeE™ SAP test, immunohistochemistry and western blotting have detected reindeer, moose and red deer cases. It was shown that testing both brainstem and lymphoid tissue from each animal increases the surveillance sensitivity. Shortcomings in the previous EU survey limited the reliability of inferences that could be made about the potential disease occurrence in Europe. Subsequently, testing activity in Europe was low, until the detection of the disease in Norway, triggering substantial testing efforts in that country. Available data neither support nor refute the conclusion that chronic wasting disease does not occur widely in the EU and do not preclude the possibility that the disease was present in Europe before the survey was conducted. It appears plausible that chronic wasting disease could have become established in Norway more than a decade ago.

• Nymo, Ingebjørg Helena; Sjøvoll, Anja; Christensen, Ellen; Lian, Hans; Tryland, Morten & Folkow, Lars [Show all 7 contributors for this article] (2017). Aspergillose hos Svalbardrype i fangenskap [Aspergillosis in a Svalbard grouse held in captivity]. Norsk veterinærtidsskrift. ISSN 0332-5741. 9(129). Full text in Research Archive
• Ricci, Antonia; Allende, A; Bolton, D.; Chemaly, M; Davies, R & Escamez, PS Fernandez [Show all 27 contributors for this article] (2017). Scientific opinion on chronic wasting disease (CWD) in cervids. EFSA Journal. ISSN 1831-4732. 15(1). doi: 10.2903/j.efsa.2017.4667. Full text in Research Archive Show summary

  In April and May of 2016, Norway confirmed two cases of chronic wasting disease (CWD) in a wild reindeer and a wild moose, respectively. In the light of this emerging issue, the European Commission requested EFSA to recommend surveillance activities and, if necessary, additional animal health risk-based measures to prevent the introduction of the disease and the spread into/within the EU, specifically Estonia, Finland, Iceland, Latvia, Lithuania, Norway, Poland and Sweden, and considering seven wild, semidomesticated and farmed cervid species (Eurasian tundra reindeer, Finnish (Eurasian) forest reindeer, moose, roe deer, white-tailed deer, red deer and fallow deer). It was also asked to assess any new evidence on possible public health risks related to CWD. A 3-year surveillance system is proposed, differing for farmed and wild or semidomesticated cervids, with a two-stage sampling programme at the farm/geographically based population unit level (random sampling) and individual level (convenience sampling targeting high-risk animals). The current derogations of Commission Implementing Decision (EU) 2016/1918 present a risk of introduction of CWD into the EU. Measures to prevent the spread of CWD within the EU are dependent upon the assumption that the disease is already present; this is currently unknown. The measures listed are intended to contain (limit the geographic extent of a focus) and/or to control (actively stabilise/reduce infection rates in an affected herd or population) the disease where it occurs. With regard to the zoonotic potential, the human species barrier for CWD prions does not appear to be absolute. These prions are present in the skeletal muscle and other edible tissues, so humans may consume infected material in enzootic areas. Epidemiological investigations carried out to date make no association between the occurrence of sporadic Creutzfeldt–Jakob disease in humans and exposure to CWD prions.

• Gedvilaite, Alma; Tryland, Morten; Ulrich, Rainer G.; Schneider, Julia; Kurmauskaite, Vaida & Moens, Ugo [Show all 9 contributors for this article] (2017). Novel polyomaviruses in shrews (Soricidae) with close similarity to human polyomavirus 12. Journal of General Virology. ISSN 0022-1317. 98(12), p. 3060–3067. doi: 10.1099/jgv.0.000948. Full text in Research Archive Show summary

  Shrews (family Soricidae) have already been reported to host microorganisms pathogenic for humans. In an effort to search for additional infectious agents with zoonotic potential, we detected polyomaviruses (PyVs) in common shrew, crowned shrew, and pygmy shrew (Sorex araneus, S. coronatus and S. minutus). From these, 11 full circular genomes were determined. Phylogenetic analysis based on large T protein sequences showed that these novel PyVs form a separate clade within the genus Alphapolyomavirus. Within this clade, the phylogenetic relationships suggest host-virus co-divergence. Surprisingly, one PyV from common shrew showed a genomic sequence nearly identical to that of the human polyomavirus 12 (HPyV12). This indicated that HPyV12 is a variant of a non-human PyV that naturally infects shrews. Whether HPyV12 is a bona fide human-tropic polyomavirus arising from a recent shrew-to-human transmission event or instead reflects a technical artefact, such as consumable contamination with shrew material, needs further investigation.

• Okeke, malachy ifeanyi; Okoli, Arinze Stanley; Canova, Diana Karina Diaz; Offor, Collins; Oludotun, Taiwo & Tryland, Morten [Show all 8 contributors for this article] (2017). Hazard characterization of modified vaccinia virus ankara vector: What are the knowledge gaps? Viruses. 9(11:318), p. 1–29. doi: 10.3390/v9110318. Full text in Research Archive Show summary

  Modified vaccinia virus Ankara (MVA) is the vector of choice for human and veterinary applications due to its strong safety profile and immunogenicity in vivo. The use of MVA and MVA-vectored vaccines against human and animal diseases must comply with regulatory requirements as they pertain to environmental risk assessment, particularly the characterization of potential adverse effects to humans, animals and the environment. MVA and recombinant MVA are widely believed to pose low or negligible risk to ecosystem health. However, key aspects of MVA biology require further research in order to provide data needed to evaluate the potential risks that may occur due to the use of MVA and MVA-vectored vaccines. The purpose of this paper is to identify knowledge gaps in the biology of MVA and recombinant MVA that are of relevance to its hazard characterization and discuss ongoing and future experiments aimed at providing data necessary to fill in the knowledge gaps. In addition, we presented arguments for the inclusion of uncertainty analysis and experimental investigation of verifiable worst-case scenarios in the environmental risk assessment of MVA and recombinant MVA. These will contribute to improved risk assessment of MVA and recombinant MVA vaccines

• Tryland, Morten; Romano, Javier Sanchez; Marcin, Nina; Nymo, Ingebjørg Helena; Josefsen, Terje D. & Sørensen, Karen Kristine [Show all 7 contributors for this article] (2017). Cervid herpesvirus 2 and not Moraxella bovoculi caused keratoconjunctivitis in experimentally inoculated semi-domesticated Eurasian tundra reindeer. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 59:23, p. 1–11. doi: 10.1186/s13028-017-0291-2. Full text in Research Archive Show summary

  Background: Infectious keratoconjunctivitis (IKC) is a transmissible disease in semi-domesticated Eurasian reindeer (Rangifer tarandus tarandus). It is regarded as multifactorial and a single causative pathogen has not yet been identified. From clinical outbreaks we have previously identified Cervid herpesvirus 2 (CvHV2) and Moraxella bovoculi as candidates for experimental investigations. Eighteen reindeer were inoculated in the right eye with CvHV2 (n = 5), M. bovoculi (n = 5), CvHV2 and M. bovoculi (n = 5) or sterile saline water (n = 3; controls). <br> Results: All animals inoculated with CvHv2, alone or in combination with M. bovoculi, showed raised body temperature, increased lacrimation, conjunctivitis, excretion of pus and periorbital oedema; clinical signs that increased in severity from day 2 post inoculation (p.i.) and throughout the experiment, until euthanasia 5–7 days p.i. Examination after euthanasia revealed corneal oedema, and three animals displayed a corneal ulcer. CvHV2 could be identified in swab samples from both the inoculated eye and the control eye from most animals and time points, indicating a viral spread from the inoculation site. <br>Conclusions: This study showed that CvHV2 alone and in combination with M. bovoculi was able to cause the characteristic clinical signs of IKC in reindeer, whereas inoculation of M. bovoculi alone, originally isolated from a reindeer with IKC, did not produce clinical signs. Previous studies have suggested that herding procedures, animal stress and subsequent reactivation of latent CvHV2 infection in older animals is a plausible mechanism for IKC outbreaks among reindeer calves and young animals in reindeer herds. However, further studies are needed to fully understand the infection biology and epidemiology associated with IKC in reindeer. Keywords: Alphaherpesvirus, Eye disease, IKC, Moraxella, Ophthalmology, Reindeer, Wildlife

• Tryland, Morten; Stubsjøen, Solveig Marie; Ågren, Erik Olof; Johansen, Bernt & Kielland, Camilla (2016). Herding conditions related to infectious keratoconjunctivitis in semi-domesticated reindeer: a questionnaire-based survey among reindeer herders. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 58(22). doi: 10.1186/s13028-016-0203-x. Full text in Research Archive Show summary

  Background: Infectious keratoconjunctivitis (IKC) in Eurasian semi-domesticated reindeer (Rangifer tarandus tarandus) is a multifactorial disease, associated to infectious agents such as Cervid herpesvirus 2 (CvHV2) and various species of bacteria, but environmental factors may also be necessary to initiate the disease. Little effort seems to have been invested in addressing the herder`s experience with this disease. An information letter with a link to an online questionnaire was sent to 410 herding community representatives in Norway and Sweden. Results: Sixty-three herders responded, 76 % of these having reindeer in Norway and 24 % in Sweden. Thirty-three herders (55 %) responded that they had seen this disease during the preceding year (2010) and 23 (38 %) that they had seen it in previous years (2009 or earlier). The majority (67 %) claimed that only 1–5 animals in their herd were affected at one time, whereas three herders (7 %) responded that more than 30 animals had been affected. No environmental factor could be singled out as significantly associated with the appearance of IKC, but when categorizing the number of contact herds for each herd (i.e. sharing pastures, corrals etc.), IKC was observed more often in herds with many (>25) contact herds. The questionnaire revealed that a veterinarian is not always available for reindeer herders, but also that a veterinarian seldom is contacted for this disease. None of the herders practiced isolation of a diseased animal from the rest of the herd when IKC was observed. Slaughter was the action most commonly initiated by the herders in response to IKC, whereas the veterinarian usually prescribed antibiotics, usually an ophthalmic ointment, alone or combined with systemic treatment. The herders claimed that IKC and other diseases had less importance than predators concerning loss of animals. Conclusions: IKC is to be considered a common disease, observed in 55 % of the herds (2010), typically affecting 1–5 animals, although larger outbreaks (>30 animals) occur. The herders usually slaughtered affected animals rather than consulting a veterinarian for medical treatment.

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• Tryland, Morten (2022). Arctic One Health - Challenges for Northern Animals and People. Springer Nature. ISBN 9783030878528. 573 p. Full text in Research Archive Show summary

  This multidisciplinary book discusses the manifold challenges arctic marine and terrestrial wildlife, ecosystems and people face these times. Major health threats caused by the consequences of climate change, environmental pollution and increasing tourism in northern regions around the globe are explored. The most common infectious diseases in wild and domesticated arctic animals are reviewed and the impact they could have on circumpolar ecosystems as well as on the lives of arctic people are profoundly discussed. Moreover, the book reviews arctic hunting, herding and food conservation strategies and introduces veterinary medicine in remote indigenous communities. "Arctic One Health" is authored by experts based in arctic regions spanning from North America over Europe to Asia to cover a broad range of topics and perspectives. The book addresses researchers in Veterinary Medicine, Ecology, Microbiology and Anthropology. The book contributes towards achieving the UN Sustainable Developmental Goals, in particular SDG 15, Life on Land.

• Tryland, Morten & Kutz, Susan J. (2018). Reindeer and Caribou: Health and disease. CRC Press. ISBN 9781482250688. 533 p. Full text in Research Archive

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• Nymo, Ingebjørg Helena; Tryland, Morten; Skarin, Anna & Byrne, Jason (2025). Lengre og varmere somre gir mer parasittsmitte med mygg / Guhkebe jïh baahkebe giesieh vielie parasihtesuetiem tjoejhkine vedtieh. Reindriftsnytt : Boazodoallu-Oddasat. ISSN 0333-4031. 2. doi: https:/www.landbruksdirektoratet.no/nb/reindrift/reindrift-i-norge/reindriftsnytt. Full text in Research Archive Show summary

  Lengre og varmere somre gir bedre levevilkår for parasitter som smitter med mygg, som bukhulemark (Setaria tundra) og «lymfemark» (Rumenfilaria andersoni). «Lymfemark» er nå for første gang påvist hos rein i Norge, noe som tyder på at den har fått større utbredelse. Mens bukhulemark gir sykdom hos rein, er det fortsatt uklart hvilken rolle «lymfemark» spiller. Guhkebe jïh baahkebe giesieh buerebe jieledeeaktoeh parasihtide vedtieh mah tjoejhkine laanestieh, goh voevtesoekse / bukhulemark (Setaria tundra) jïh «lymfesoekse / lymfemark» (Rumenfilaria andersoni). Daelie «lymfesoekse» voestes aejkien bovtsine Nöörjesne gååvnesovveme, naakede mij daejrehte dïhte vijriegåbpoe saaseramme. Mearan voevtesoekse skïemtjelassem bovtsi luvnie vadta, dle annje ånnetji jueriedisnie «lymfesoeksen» råållan bïjre.

• Nymo, Ingebjørg Helena; Tryland, Morten; Aurbakken, Stine Emilie Bull; Malmström, Anna Ester Emilia; Baron, Jerome & Josteinsdottir, Alfa Bachmann [Show all 10 contributors for this article] (2025). Hva betyr fôring for reinens helse? / Mo biebman váikkuha bohcco dearvvašvuhtii? Reindriftsnytt : Boazodoallu-Oddasat. ISSN 0333-4031. 2. doi: https:/www.landbruksdirektoratet.no/nb/reindrift/reindrift-i-norge/reindriftsnytt. Full text in Research Archive Show summary

  Fôring har blitt en viktig del av reindrifta i både Norge og Sverige, særlig på grunn av arealtap og vanskelige beiteforhold på vinteren. Hva betyr dette for reinens helse? En spørreundersøkelse blant reineiere ga innsikt i fôring, sykdommer og bruk av veterinærtjenester. Bohccuid biebman lea šaddan dehálaš oassin boazodoalus sihke Norggas ja Ruoŧas, erenoamážit areálamassima ja hástaleaddji guohtumiid dihte. Mo dat váikkuha bohcco dearvvašvuhtii? Boazoeaiggádiid jearahallamat adde ipmárdusa biebmamis, buozalmasvuođain ja šibitdoavttirbálvalusaid geavaheamis.

• Skjerdal, Olaug Taran; Aspholm, Marina Elisabeth; Grahek-Ogden, Danica; Myrmel, Mette; Møretrø, Trond & Tryland, Morten [Show all 9 contributors for this article] (2025). Protocol: Assessment of the shelf-life for table eggs. VKM Bulletin. VKM Bulletin(VKM Bulletin 2025: 10), p. 1–13. Full text in Research Archive Show summary

  In connection with regulatory development under the European Commission and the preparation of a possible text adapted to/influencing of new changes in the animal hygiene regulations, the Norwegian Food Safety Authority has commissioned a knowledge summary and risk assessment related to the shelf life of table eggs in Norway. VKM's Panel for Biological Hazards has established a project group which has developed a protocol for the assessment. The same project group will prepare a draft for the assessment. The assessment will be approved by the Panel of Biological Hazards and is scheduled to be published in January 2025.

• Nymo, Ingebjørg Helena; Davidson, Rebecca K.; Mørk, Torill; Olsen, Line; Spilsberg, Bjørn & Bøe, Cathrine Arnason [Show all 15 contributors for this article] (2024). Sykdommen reinkopper gir sår og skorper rundt øyne og kjønnsorgan hos rein. Reindriftsnytt : Boazodoallu-Oddasat. ISSN 0333-4031. Full text in Research Archive
• Rinaldo, Christine Hanssen & Tryland, Morten (2023). State-of-the-Art Virology Research in Norway. Viruses. 15(12). doi: 10.3390/v15122383. Full text in Research Archive
• Nymo, Ingebjørg Helena; Mørk, Torill; Olsen, Line; Davidson, Rebecca K.; Spilsberg, Bjørn & Bøe, Cathrine Arnason [Show all 14 contributors for this article] (2023). Sår rundt øynene hos rein med ukjent årsak. Reindriftsnytt : Boazodoallu-Oddasat. ISSN 0333-4031. Full text in Research Archive
• Romano, Javier Sanchez; Aurosell, Caroline; Fedorov, Valery; Hagström, Åsa; Kantanen, Juha & Leijon, Mikael [Show all 17 contributors for this article] (2021). Seroprevalence of pestivirus – a potential viral health threat to semi-domesticated and wild reindeer in the Nordic countries and Russia. Full text in Research Archive Show summary

  Eurasian tundra reindeer is a keystone species in the Arctic and sub-Arctic areas of the Nordic countries and Russia. While a few wild populations exist, semi-domesticated reindeer comprise most of the herds in these countries. Reindeer herding has been of great importance for the indigenous people in the Arctic for at least 500 years. Today, climate change and other anthropogenic changes are threatening the traditional ranges of reindeer herding, among other things, by increasing the prevalence of microbial pathogens. Pestiviruses are known to cause serious health problems in ungulates worldwide. The present study aimed to determine the current seroprevalence for pestiviruses in semi-domesticated (n=392) and wild reindeer (n=128). In addition, direct screening by a pan-pestivirus real-time RT-PCR in seronegative animals was performed. Seroprevalence was higher in Sweden (48.5%, n=133) and Norway (41.2%, n=119) as compared with Finland (2.5%, n=122) and Iceland (1.6%, n=128). No seropositive animals were detected in Russia (n=19). Real time RT-PCR of seronegative animals (n=156) from seropositive herds confirmed their negative status. These results confirm the circulation of pestivirus in semi-domesticated reindeer in Fennoscandia, and for the first time, detected pestivirus seropositive reindeer in Iceland. Further studies are needed to better understand epidemiology of the pestivirus infection and the effect of the virus on reindeer health and population dynamics.

• Albihn, Ann; Omazic, Anna; Hagström, Åsa; Tryland, Morten; Kantanen, Juha & Romano, Javier Sanchez [Show all 10 contributors for this article] (2021). Virome in Eurasian tundra reindeer (Rangifer t. tarandus) in Norway, Sweden, Finland and Russia – Evidence from Next-Generation-Sequencing (NGS). Full text in Research Archive Show summary

  Reindeer husbandry is essential for the livelihood and culture of indigenous people in the Arctic. Parts of the herding areas are also used as pastures for farm animals, facilitating potential transmission of viruses between species. Further, following the COVID-19 pandemic, viruses circulating in the wild have received increased attention since they might be a potential threat for human health. Climate change influence the prevalence of infectious diseases for both humans and animals. Better knowledge is needed about the present situation of these diseases, to recognize future changes. This study aimed to detect known and previously unknown viruses in Eurasian tundra reindeer. In total, nasal swabs (575 animals) and rectal swabs (430 animals) were collected from healthy reindeer at slaughter in three herds in Norway, Sweden and Finland, respectively, and from two herds in Russia, twice from each herd during 2016-2019. Samples were pooled 5 by 5. NGS was performed on MiSeq (Illumina) with MiSeq Reagent kit v3 (600 cycle) after tagmentation with Nextera XT Index Kit (Illumina). Preliminary results from BLAST-homology search indicate the presence of viruses, associated with different wild and domesticated animal species, similar to e.g Betaherpesvirinae, Papillonaviridae, Adenoviridae, Parvoviridae, Paramyxoviridae, Flaviviridae (Pegivirus and Pestivirus), Gammaherpesvirinae (Macavirus) and Smacoviridae. Several viral species previously found in reindeer were detected, as well as novel ones. The clinical relevance of these viruses in reindeer is largely unknown. Although, results indicate that it should be possible to find emerging viruses of relevance for both human and animal health, using reindeer as a sentinel species.

• Rockström, Ulrika; Albihn, Ann; Tryland, Morten; Romano, Javier Sanchez; Ågren, Erik & Risvoll, Camilla [Show all 8 contributors for this article] (2021). Climate change will increase the risk for infectious diseases in the mouth and eyes of reindeer in the Nordic countries. Full text in Research Archive Show summary

  Climate change and extreme weather events may increase the risk for infectious diseases and change their epidemiology. Reindeer herding in the Nordic countries will be heavily affected. Warmer winters and increased precipitation will cause more frequent freeze- thaw events and form an ice cover on the ground. This hinders the reindeers’ ability to both smell the forage under the ice and to reach it through digging. To avoid starvation, reindeer are fed with supplementary fodder in the field or in enclosures. This mitigation strategy is saving reindeer lives, but also leads to stress, increased animal density, and challenging hygienic conditions which increases the risks for infectious disease transmission. Infectious diseases of the mucosa of the eyes and mouth are increasingly observed. Examinations in the field and at slaughter have confirmed that herpesvirus and Chlamydia are important agents causing eye infections in reindeer. Serious oral infections, e.g. Orf and necrobacillosis are common causes to lesions in the mouth. These infections are highly contagious and require immediate action by the herder and measures to reduce animal suffering and economic loss for the herder include separating affected animals from healthy, medical treatment if possible, but also slaughter or euthanasia. Further studies on reindeer herder knowledge and perception regarding eye and mouth infections; how these affects the reindeer and herders’ strategies to handle this problem is ongoing.

• Tryland, Morten; Lydersen, Christian; Kovacs, Kit M.; Rafter, Espen & Thoresen, Stein Istre (2021). Correction to: Serum biochemistry and haematology in wild and captive bearded seals (Erignathus barbatus) from Svalbard, Norway (Acta Veterinaria Scandinavica, (2021), 63, 1, (33), 10.1186/s13028-021-00598-8). Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 63(1). doi: 10.1186/s13028-021-00602-1. Full text in Research Archive
• Tømmervik, Hans; Rydén, Patrik; Bartsch, Annett; Goldenberg, Romain; Tryland, Morten & Riseth, Jan Åge [Show all 15 contributors for this article] (2021). Linkage between temperature anomalies and outbreaks of climate-sensitive infectious diseases in Arctic reindeer herds. Full text in Research Archive
• Routti, Heli; Bourgeon, Sophie; Diot, B.; Duale, Nur; Fisk, A. T. & Fossi, M. [Show all 15 contributors for this article] (2018). Sucking clams or hunting seals - consequences to walrus health. Full text in Research Archive
• Romano, Javier Sanchez; Sørensen, Karen Kristine; Nymo, Ingebjørg Helena; Mørk, Torill & Tryland, Morten (2018). Histopathological study of eye tissues from semi-domesticated reindeer with infectious keratoconjunctivitis caused by cervid herpesvirus 2 in an experimental setting. Full text in Research Archive Show summary

  The aim of this study was to describe the histopathology of eye tissues caused by Cervid Herpesvirus 2 (CvHV2) in experimentally induced infectious keratoconjunctivitis (IKC) in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus). IKC is a common disease in Scandinavian reindeer and can affect a great number of animals during outbreaks, with calves and young animals being the most susceptible age group. Eighteen 1-year old reindeer calves, seronegative for alphaherpesvirus and culture negative for Moraxella bovoculi, were inoculated with CvHV2 (Group 1, n = 5), a combination of CvHV2 and M. bovoculi (Group 2, n = 5), M. bovoculi (Group 3, n = 5) or sterile saline water as a negative control (Group 4, n = 3). All 10 animals inoculated with CvHV2, alone or in combination with M. bovoculi, developed clinical signs of IKC within 2-3 days after inoculation. Animals that were only inoculated with M. bovoculi did not develop lKC during the study period. All reindeer eyes, including the tissue from the periorbital region, were fixed with 4 % paraformaldehyde in PBS within minutes after euthanization of the animals. Subsequently, tissues from the upper and lower eyelids, cornea and lacrimal glands were collected from each eye and processed routinely for histological examination. Paraffin-embedded sections stained with hematoxylin and eosin were subjected to a blind histological examination. Major structures in the different tissues were graded in a five-grade severity scale, with 1 being used for normal tissue, 2 for mild pathological lesions, 3 for moderate inflammation, 4 for focal severe inflammation and 5 for general and severe inflammation. A general evaluation of the tissue was also performed, grading the whole section from 1 to 5. Histopathological analysis of the tissues collected from the experimental animals in groups 1 and 2 showed the presence of exudates, edema, hyperemia, hemorrhage, necrosis, vascular thrombosis, vascular necrosis, infiltration of mononuclear cells and neutrophils, pus and lymphoid follicle reaction. In contrast, no apparent pathology of the mucosal or corneal epithelium was visible in the tissues collected from groups 3 or 4. The histopathological examination showed that CvHV2 had the ability to cause severe pathology (i.e. inflammation, necrosis) in all ocular structures examined in our study, e.g. conjunctival tissue, cornea or lacrimal glands, while the M. bovoculi isolate used in the challenge experiment did not. These findings are consistent with the macroscopic lesions described in previous studies and support the theory of CvHV2 as a primary causative agent of IKC in semi-domesticated reindeer.

• Tryland, Morten (2018). Skrantesjuken i Norge. Full text in Research Archive
• Tryland, Morten; Romano, Javier Sanchez; Nymo, Ingebjørg Helena; Magnuson, Emily Elisabeth & Li, Hong (2018). Serological screening for viral pathogens among semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) from eight reindeer herding districts in Norway. Full text in Research Archive
• Romano, Javier Sanchez; Tryland, Morten; Angelos, John A.; Mørk, Torill; Nymo, Ingebjørg Helena & Sørensen, Karen Kristine (2017). The pathogenic role of Moraxella bovoculi in infectious keratoconjunctivitis in semi-domesticated reindeer. Full text in Research Archive
• Mørk, Torill; Blomstrand, Berit Marie; Nymo, Ingebjørg Helena; Romano, Javier Sanchez; Gjerset, Britt & Tryland, Morten (2017). A case of sheep-associated Malignant catarrhal fever in domestic reindeer (Rangifer tarandus tarandus). Full text in Research Archive
• Romano, Javier Sanchez; Mørk, Torill; Laaksonen, Sauli; Ågren, Erik; Nymo, Ingebjørg Helena & Sunde, Marianne [Show all 7 contributors for this article] (2017). Infectious keratoconjunctivitis in semidomesticated reindeer. Full text in Research Archive
• Tryland, Morten; Beckmen, Kimberly; Burek-huntington, Kathleen; Breines, Eva Marie & Klein, Joern (2017). Orf virus in Alaskan mountain goats, Dall’s sheep, muskoxen, caribou and Sitka black-tailed deer – a zoonotic risk for hunters and game managers. Full text in Research Archive
• Tryland, Morten (2017). Sykdommer hos rein - smittsom øyebetennelse og skrantesjuken. Full text in Research Archive
• Tryland, Morten (2017). Skrantesjuken (CWD) - en ny utfordring for reindrifta? Full text in Research Archive
• Tryland, Morten (2017). Chronic wasting disease - a game changer for wild cervids and reindeer husbandry. Full text in Research Archive
• Nymo, Ingebjørg Helena; Rockström, Urlika; Mørk, Torill; Ågren, Erik Olof & Tryland, Morten (2016). Mixed infectious disease outbreak in a herd og semi-domesticated reindeer in Sweden: Alphaherpesvirus, parapoxvirus and oral necrobacillosis. Full text in Research Archive
• Byrne, Jason; Nymo, Ingebjørg Helena; Davidson, Rebecca K.; Buhler, Kayla Joy; Sundset, Monica Alterskjær & Tryland, Morten (2025). Filarioid nematodes in Fennoscandian reindeer (Rangifer tarandus tarandus). UiT Norges arktiske universitet. Full text in Research Archive Show summary

  Reindeer (Rangifer tarandus) are a keystone species across an array of contexts – culturally, ecologically and economically, at least. Reindeer are intrinsically interwoven into the way of life for many Indigenous groups of humans across the globe, of most significance to the work entailed in this project are the Sámi people of Sápmi across Northern Fennoscandia. Climate change is estimated to be happening in the Arctic at four times the rate of warming than that observed in temperate parts of the world. Along with land-use conflicts from industrial activities and infrastructural development, reindeer and the reindeer herding way of life are being faced with complex, multi-faceted challenges. Of particular note is the impact of climate change on biting insect (notably mosquito) population dynamics and habitat range expansion. This in turn facilitates the transmission of climate sensitive infections such as Setaria tundra, and Rumenfilaria andersoni. In this project, direct detection methods (hematocrit tube, and Modified Knott’s Assay) were utilised alongside a molecular workflow (PCR and Sanger Sequencing), for the detection, quantification and identification of these parasites in reindeer blood samples obtained from reindeer herding communities across Norway (n = 3) and Sweden (n = 3). These analyses shed light on the current state of the prevalence, abundance and intensity of the parasites in both countries. Setaria tundra and R. andersoni were detected in a reindeer herding community in Norrbotten, Sweden. Rumenfilaria andersoni was also detected in a reindeer herding community in Finnmark, Norway. This marks the first officially reported case of this parasite in reindeer in Norway.

• Miller, Andrea; Tryland, Morten; Eide, Nina Elisabeth & Ytrehus, Bjørnar (2024). Risikovurdering av helsetrusler hos fjellrev i Norge og forslag til beredskapsplan(er). Norsk institutt for naturforskning (NINA). ISSN 9788242649201. Full text in Research Archive Show summary

  Miller, A., Tryland, M., Eide, N.E. & Ytrehus, B. 2024. Risikovurdering av helsetrusler hos fjellrev i Norge og forslag til beredskapsplan(er). NINA Rapport 2553. Norsk institutt for naturforskning. Fjellreven (Vulpes lagopus) er en sterkt truet art i Fastlands-Norge og Sverige og kritisk truet i Finland. Man har over lang tid gjort et stort bevaringsarbeid for å bygge opp en levedyktig bestand. Smittsomme sykdommer og dårlig helse kan imidlertid forårsake raske og uforutsigbare bestandsnedganger, spesielt når det er få dyr i utgangspunktet. Denne rapporten beskriver aktuelle sykdommer og patogener som kan utgjøre en trussel mot god helse hos fjellrevbestandene i Fennoskandia. Disse truslene blir rangert etter hvor stor risiko de utgjør for bestanden. Vurderingen omfatter både den frittlevende bestanden og den delen av bestanden som holdes på Oppdal knyttet til Avlsprogrammet. I denne risikovurderingen identifiseres valpesyke, rabies, parvovirus, smittsom leverbetennelse og skabb som noen av de største helsetruslene. Tjueåtte andre sykdommer/patogener er også omhandlet og rangert. Det kan være aktuelt å iverksette tiltak når sykdom truer fjellrevbestanden gjennom økt dødelighet, nedsatt reproduksjon eller dårligere kondisjon, som igjen svekker fjellrevens evne til å håndtere andre trusler. Tiltak kan også være aktuelle om sykdom hos fjellrev utgjør en trussel mot folkehelsen eller helsen til husdyr. Solid kunnskap er en forutsetning for å kunne gjennomføre tiltak. Løpende overvåking av dyrehelsetilstanden i Norge og utlandet, målrettet helseovervåking av viltlevende fjellrev og rødrev og undersøkelser av fjellrev som blir funnet døde eller syke vil over tid danne et godt kunnskapsgrunnlag. For hver sykdom/patogen som nevnes, beskriver vi også mulige tiltak. Tiltak for å beskytte fjellreven mot truslene kan rettes mot den aktuelle fjellrevbestanden, mot andre arter, eller miljøet. De kan omfatte for eksempel forebyggende tiltak som vaksinasjon og behandling, ferdselsrestriksjoner, hygienetiltak eller uttak av syke og/eller mottakelige individer. Basert på kunnskapssammenstillingen har vi satt opp en skisse til en generell beredskaps- og kommunikasjonsplan. Rapporten beskriver hvordan beredskapen mot helsetrusler hos fjellrev kan styrkes og organiseres gjennom opprettelsen av en struktur med en veterinærfaglig ansvarlig som har helseovervåking hos fjellrev som en del av sitt daglige arbeid, en rådgivergruppe som skal gi faglige råd når det oppstår helsetrusler og et forvaltningsutvalg som gir vurderinger og tar beslutninger om tiltak. Forvaltningsvedtak gjøres fortsatt av en kompetent myndighet. Denne strukturen ble diskutert i en workshop sammen med relevante interessenter gjennom tre mulige sykdomsutbrudds scenarioer. Kommentar og endringer er inkludert i rapporten. Rapporten inneholder også en revidert beredskapsplan for utbrudd av skabb. Mulige styrker og svakheter ved risikovurderingen blir også diskutert, og det gis en kortfattet oversikt over framtidens behov for overvåking med spesielt henblikk på sykdommer som kan utgjøre en større risiko ved klimaendring eller introduksjon av fremmede arter, slik som fransk hjerteorm (Angiostrongylus vasorum) og flåttbårne sykdommer.

• Romano, Javier Sanchez; Tryland, Morten; Nymo, Ingebjørg Helena; Larsen, Anett Kristin & Sørensen, Karen Kristine (2019). Infectious keratoconjunctivitis in reindeer - The role of the reindeer alphaherpesvirus. UiT Norges arktiske universitet. ISSN 9788282661638. Full text in Research Archive Show summary

  Semi-domesticated reindeer (Rangifer tarandus tarandus) have been herded in Fennoscandia for hundreds of years. Many infectious diseases have struck semi- domesticated reindeer herds during this period, e.g. anthrax, necrobacillosis and pasteurellosis, as well as the reindeer pest, Pestis tarandi. Infectious keratoconjunctivitis (IKC), a widespread ocular disease among ruminants, is not an exception and large outbreaks have taken place in semi-domestic reindeer. IKC is often neglected as a disease of lesser importance; since in most cases only a few animals are affected and with a mild clinical manifestation, i.e. increased lacrimation, ocular discharge or mild conjunctivitis. However, in some cases, the disease spreads among the herd, affecting tens or hundreds of animals and severe clinical signs can appear, i.e. purulent secretions, corneal and periorbital edema, severe conjunctivitis, and keratitis, which sometimes progress to corneal ulcers and rupture of the eye globe. The aim of the present study was to investigate the pathogenesis of IKC in reindeer. In order to accomplish this objective and better understand how the disease develops, the main candidates as primary causative agents of IKC in reindeer, i.e. Cervid herpesvirus 2 (CvHV2), Moraxella spp. and Chlamydia spp, were studied. In the work presented here, CvHV2 is reported as a major component in the development of the disease. Both as the primary causative agent, being able to cause the clinical signs and pathology associated with IKC in reindeer, and as an initiator of a primary infection, destroying the mucosal membranes of the eye and facilitating secondary bacterial infections that worsen the clinical signs of affected animals. It was also discovered how bacteria of the family Chlamydiaceae, under the right circumstances, can be involved in IKC outbreaks in reindeer. This study has further emphasized the need for early detection of the pathogens involved. The lack of a suitable treatment against CvHV2 and its enzootic status make it difficult to control outbreaks of IKC with viral origin. The characterization of the pathogenicity of Moraxella bovoculi reindeer isolates would also help to determine whether this bacterium is a primary or opportunistic agent in the pathogenesis of IKC. The zoonotic potential of the chlamydial species identified during the outbreak remains unclear, but cannot be excluded, making preventive measures to avoid transmission of this pathogen from animal to herder while working with affected animals. Hence, more information is needed regarding both viral and bacterial agents involved in the pathogenesis of IKC in reindeer, and further investigations must be completed in order to fully understand this multifactorial and complex disease.

• Nordgård, Lise; Olsen, Elisabeth; Furuholmen, IS; Tryland, Morten & Nielsen, Kaare Magne (2017). Prevalence of Antibiotic Resistance Marker Genes (ARMG) in Selected Environments in Norway – Reindeer, M909|2017. Miljødirektoratet. Full text in Research Archive

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