Prevalence of pestivirus in reindeer : a study of reindeer populations in Finland, Iceland, Norway and Sweden

Abstract: Pestivirus includes four viral species, causing disease and major economic losses in animal production all over the world. The viruses can also infect a wide range of wild animal species, of which the clinical relevance of pestivirus infection is not much investigated. Reindeer kept for reindeer husbandry are of great importance for the indigenous people in Finland, Norway and Sweden, both economically and culturally. There is also a free-ranging feral population of reindeer in Iceland. The present study analysed sera from 217 reindeer in Finland, Iceland Norway and Sweden. Specific antibodies to pestivirus were analysed by an enzyme-linked immunosorbent assay (ELISA), and were found in samples from Iceland (8%), Norway (43.3%) and Sweden (49.3%). No seropositive animals were found in Finland. Negative samples from reindeer in populations where specific antibodies had been found were further analysed for pestivirus RNA by a real-time reverse transcription polymerase chain reaction (RT-PCR). This was done to find possible persistently infected animals. However, no pestivirus RNA was found. In addition, two samples from each population (in total 14 samples) with positive results from the ELISA, and one sample from Finland with a doubtful result, were further analysed by a virus neutralisation test (VNT). The VNT could confirm the positive ELISA results, and the sample with a doubtful result was shown to be negative in the VNT.