Specificity of pestivirus antibodies in wild ruminants from Switzerland.

Abstract

Switzerland started a bovine viral diarrhoea (BVD) national eradication campaign in 2008. BVD virus (BVDV) belongs together with classical swine fever virus (CSFV) of pigs and border disease virus (BDV) of sheep to the genus Pestivirus. Ruminant pestiviruses are not strictly hostspecifi c and interspecies virus transmission is possible (Vil ek and Nettleton, 2006). In Switzerland, the shared use of Alpine pastures by multiple cattle herds during the summer grazing season is a widespread tradition. In this practice, cattle can share the grazing grounds with wild ruminants; these may be recipients as well as donors of pestiviruses. In the Pyrenees, for example, massive losses in chamois due to infection with border disease virus are reported (Arnal et al., 2004). In the French and Italian Alps, pestivirus antibodies have been detected in chamois, ibex, roe and red deer, moufl ons and wild boar (Olde Riekerink et al., 2005; Fernandez et al., 2011). In order to determine if wild ruminants may play a role in pestivirus epidemiology in Switzerland, a virological and serological survey was carried out in 2009 – 2011 (Casaubon et al., 2012). Results revealed very low seroprevalences in Alpine chamois (Rupicapra rupicapra rupicapra), Alpine ibex (Capra ibex ibex) and red deer (Cervus elaphus elaphus) of 2.1 %, 1.8 % and 2.7 %, respectively. The determination of the specifi city of pestivirus antibodies, i. e. against which pestivirus species they are directed, can give indication on the origin of the infection and therefore enhance our knowledge on interspecies transmissions of pestiviruses to wild ruminants. Therefore, the present study was raised with the aim to specify the antibodies detected in red deer, Alpine chamois and ibex by using a comparative serum neutralization test (SNT).