Evidence of alphaherpesvirus infections in Alaskan caribou and reindeer

doi:10.1186/1746-6148-8-5

BMC Vet Res. 2012; 8: 5.

Published online 2012 January 14. doi: 10.1186/1746-6148-8-5

PMCID: PMC3274481

Evidence of alphaherpesvirus infections in Alaskan caribou and reindeer

Alina L Evans,^1,² Carlos G das Neves,¹ Greg F Finstad,³ Kimberlee B Beckmen,⁴ Eystein Skjerve,⁵ Ingebjørg H Nymo,¹ and Morten Tryland¹

¹Section of Arctic Veterinary Medicine, Norwegian School of Veterinary Science, Stakkevollveien 23, N-9010 Tromsø, Norway

²Department of Forestry and Wildlife Management, Hedmark University College, Campus Evenstad NO-2418 Elverum, Norway

³University of Alaska Fairbanks, Reindeer Research Program. Box 757200, Fairbanks Alaska 99775. USA

⁴Alaska Department of Fish & Game, Division of Wildlife Conservation, 1300 College Road, Fairbanks AK 99701. USA

⁵Centre for Epidemiology and Biostatistics, Norwegian School of Veterinary Science, P.O.Box 8146, NO-0033 Oslo, Norway

Corresponding author.

Alina L Evans: alinaevans/at/gmail.com; Carlos G das Neves: Carlos.dasNeves/at/nvh.no; Greg F Finstad: glfinstad/at/alaska.edu; Kimberlee B Beckmen: kimberlee.beckmen/at/alaska.gov; Eystein Skjerve: Eystein.Skjerve/at/nvh.no; Ingebjørg H Nymo: Ingebjorg.Nymo/at/nvh.no; Morten Tryland: Morten.Tryland/at/nvh.no

Received May 8, 2011; Accepted January 14, 2012.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

The reindeer (Rangifer tarandus tarandus) industry in Alaska began with animals imported from Siberia (Russia) in the 1890's. Cervid herpes virus 2 (CvHV2) is endemic in reindeer in Scandinavia. We sought to determine if the same virus, or similar herpesviruses, were circulating in Alaskan reindeer and caribou (Rangifer tarandus granti). Serum samples from 292 reindeer were collected during annual reindeer handlings (1988-2005) near Nome, Alaska. In 2005, swab samples were collected from 40 calves from this herd, near Nome, Alaska. In 2007, ocular and nasal swab samples were collected from 30 apparently healthy reindeer calves near Wales, Alaska. Samples of plasma and white blood cells were collected from three Alaskan caribou herds, Mulchatna (n = 24), Teshekpuk (n = 34) and the Western Arctic (n = 87) in 2009.

Results

Of 292 reindeer samples tested by ELISA for antibodies against alphaherpesvirus (bovine herpesvirus 1 as antigen), seroprevalence was 47% (136/292) and adult reindeer had higher seroprevalence than yearlings. The overall seroprevalence for caribou was 60% (87/145), with no significant differences among caribou herds. A virus neutralization test of 20 samples from both reindeer and caribou showed that ELISA positive samples always neutralized CvHV2 to a greater extent than BoHV1 or elk herpesvirus (ElkHV), indicating that CvHv2 is the most likely virus circulating. PCR of nasal and ocular swabs sampled from 30 reindeer calves in Wales, Alaska (2007) yielded four CvHV2 positive samples. PCR amplicons of the expected size (294 bp) were obtained from 2 of the 36 buffy coats samples from caribou, and the amplicon sequences were consistent with CvHV2.

Conclusions

This study shows that Alaskan reindeer and Caribou are infected with an alphaherpesvirus. Based on sequence similarity, CvHV-2 is the most likely virus. Further studies should be conducted to determine the impact of this infection on the health of these animals.

Keywords: caribou, epidemiology, herd health, herpesvirus infectious diseases, reindeer, Rangifer, wildlife medicine

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