A Screening for Virus Infections in Eight Herds of Semi-domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Norway, 2013–2018

Abstract

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.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.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.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.

Serological Evidence of Hepatitis E Virus Infection in Semi-Domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Norway

“…While the Norwegian study of wild reindeer was based on the same ELISA as used in the present study, an ELISA detecting anti-HEV IgM, IgA and IgG, the Russian study used an ELISA only detecting anti-HEV IgG, which may indicate that these screenings are not necessarily directly comparable. Finally, comparing our results with the results of a recently published study on the same samples, addressing other viruses [31], the serostatus for HEV and pestivirus and HEV and CVHV2 were found to correlate.…”

“…As some of the serum samples had recently been found to contain antibodies against pestivirus, alphaherpesvirus (i.e., Cervid herpesvirus 2; CvHV2) and/or gammaherpesvirus (viruses in the malignant catarrhal fever group; MCFV) [31], we investigated if there was an association between the HEV serostatus of a sample and the presence of antibodies against the previously investigated viruses. Overall, only small differences of 1.2-1.5-fold were detected between HEV-seropositive and HEV-seronegative animals for the three viruses (Table 3).…”

“…Serum was prepared by centrifugation (10 min, 3000 × g) and stored at -20 • C until further analyses. The serum had been thawed a few times prior to the HEV antibody analysis for the previous seroprevalence study of alphaherpesvirus, gammaherpesvirus, pestivirus, bluetongue virus and Schmallenberg virus [31].…”

“…Each individual's age group (calf or adult), latitude, sex and sampling season were used as explanatory variables; the significance level was set to p < 0.05 for the explanatory variables. In order to discover a relation between the HEV serostatus and the serostatus of the previously investigated viruses [31], we performed a multiple correspondence analysis [50] using year, latitude, sex, age and the serostatus for these viruses as contrasts. Apparent correlations were further studied with Chi-squared tests to conclude if there was a correlation between the different infections.…”

Inkoo and Sindbis viruses in blood sucking insects, and a serological study for Inkoo virus in semi-domesticated Eurasian tundra reindeer in Norway

“…Blood tubes were centrifuged at 3500 rpm for 10 min to collect the serum. Sera were stored at − 20 °C until analysis [ 37 ].…”