A screening for virus infections among wild Eurasian tundra reindeer (Rangifer tarandus tarandus) in Iceland, 2017-2019

Authors: TRYLAND, MORTEN - The Arctic University Of Norway (UIT); ROMANO, JAVIER - University Of Norway; NYMO, INGEBJØRG - Norwegian Veterinary Institute; MØRK, TORILL - Norwegian Veterinary Institute; ÞÓRARINSDÓTTIR, RÁN - University Of Iceland; BREINES, EVA - University Of Norway; LI, HONG - Retired ARS Employee; Cunha, Cristina; THÓRISSON, SKARPHÉÐINN - University Of Iceland

Submitted to: Viruses
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2023
Publication Date: 1/23/2023
Citation: Tryland, M., Romano, J., Nymo, I., Mørk, T., Þórarinsdóttir, R., Breines, E., Li, H., Cunha, C.W., Thórisson, S. 2023. A screening for virus infections among wild Eurasian tundra reindeer (Rangifer tarandus tarandus) in Iceland, 2017-2019. Viruses. 15(2). Article 317. https://doi.org/10.3390/v15020317.
DOI: https://doi.org/10.3390/v15020317

Interpretive Summary: Iceland has a population of about 4000-5000 wild Eurasian tundra reindeer (Rangifer t. tarandus) that are most likely all descendants from an import of 35 semi-domesticated reindeer from Finnmark, Norway, in 1787. The animals are distributed into nine different management zones in the north-east and south-east of Iceland. There are no predators for reindeer in Iceland and hunting is used the main tool for regulating the population. Limited information exists on the exposure of the population to pathogens. The aim of this study was to investigate the presence of common reindeer viral pathogens in Iceland. Blood samples collected during the hunting seasons in 2017-2019 were tested for viral antibodies or viral DNA using enzyme-linked immunosorbent assays (ELISA) and PCR, respectively. From a total of 280 samples tested for antibodies, two were positive to pestisvirus and other two for a malignant catarrhal fever virus. No antibodies to cervid herpesvirus 2, bluetongue virus or Schmallenberg virus, were detected. Parapoxvirus-specific DNA was detected in nasal swabs from two out 181 animals sampled. These investigations indicate that none of the viral infections addressed in this study are enzootic in the Icelandic reindeer population, and that pestivirus, malignant catarrhal fever virus, and parapoxvirus are present at low prevalence only, probably not representing a major threat to this reindeer population.

Technical Abstract: Background: A winter population of around 4000-5000 Eurasian tundra reindeer (Rangifer t. tarandus) that are roaming freely as wild reindeer in the eastern part of Iceland are most likely all descendants from an import of 35 semi-domesticated reindeer from Finnmark, Norway, in 1787. While some studies have previously indicated that this population host few parasite species as compared to reindeer in Fennoscandia, little information exists on their exposure to known reindeer viral pathogens. The aim of this study was to investigate blood from hunted reindeer for antibodies against alpha- and gamma-herpesviruses (malignant catarrhal fever viruses; MCFV), pestivirus, bluetongue virus and Schmallenberg virus, and to investigate mucosal membrane (nasal and oral mucosa) swab samples for the presence of parapoxvirus-specific DNA. Methods: Blood samples collected during the hunting seasons in 2017 (n=40), 2018 (n=102) 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. Results: Antibodies against pestivirus were detected in two animals from 2017, but not in animals sampled in 2018 and 2019. Other two animals were seropositive to MCFV. No antibodies were detected against the other viruses tested. Parapoxvirus-specific DNA was detected in nasal swab samples from two animals sampled in 2019. Conclusions: These investigations indicate that none of the viral infections addressed in this study are enzootic in the Icelandic reindeer population, and that pestivirus, MCFV, and parapoxvirus are present at low prevalence only, probably not representing a major threat to this reindeer population.