Studies on the seroprevalence of pestivirus infections in the goat population of Vorarlberg (Austria)

Introduction BDV in sheep and goats has a worldwide distribution and is responsible for economic losses each year. In the epidemiology of pestiviruses in goats persistently infected cattle and sheep play a key role in the spread of the viruses. The purpose of this study was to estimate the prevalence of antibodies against pestiviruses in goats in Austria. Moreover the influence of different farming practices on the spread of pestiviruses was investigated. Material and methods In this study 1,196 blood samples from goats of 163 flocks were collected in Vorarlberg, one of 9 Federal states of Austria, between November 2005 and February 2006. The blood samples were tested by enzyme-linked immunosorbent assay (Svanovir BDV-Ab ELISA; Svanova, Biotech AB, Uppsala, Sweden) and virus neutralisation tests for antibodies against BVDV-1 (strain NADL), BVDV-2 (strain 125) and BDV (strain MOREDUN). Informations according breed, age and sex of the tested goats as well as detailed facts according the farm practices were raised. Results A herd prevalence of 24.5 % and an individual prevalence of 5.6 % were found in the study described here. Among animals older than 3 years the seroprevalence was significantly higher (p <0.001) compared to the prevalence in younger animals. Goats with a contact to BVD affirmative or suspected cattle herds showed an individual prevalence of 17.2 % and a herd prevalence of 50 %. The individual prevalence as well as the herd prevalence was significantly higher in these animals (p=0.001; p=0.003) than in goats and goat flocks without such contacts, respectively (4.2 % and 20.6 %). A significant difference between the flock prevalence in herds with fertility problems (35.7 %) and flocks without reproductive failures (20.7 %) was not revealed (p=0.051). Significant differences in the prevalence rate between different parts of Vorarlberg and different farming practices were not revealed. Of the 67 ELISA positive samples 24 samples showed the highest titre to BVDV-1 and 34 to BDV. Conclusion BDV as well as BVDV are endemic in the goat population in Vorarlberg. Among goats having contact to cattle herds with BVDV problems more antibody positive animals were detected. In Austria in 2004 a BVDV eradication program was established in cattle. If this program will be successful, BVDV will be eradicated in cattle in Austria in the near future. In view of the presented results and the fact that an interspecies transmission of pestiviruses among ruminants is possible the epidemiology of pestiviruses among goats has to be further observed in Austria. A persistently infected goat would be a potential risk factor for cattle susceptible for pestiviruses especially on a large alpine meadow, where hundreds of goats and mostly pregnant cattle graze together during summertime.