Editorial: Control of Pestivirus Infections in the Management of Wildlife Populations

The genus pestivirus in the Flavivirus family is comprised of single-stranded RNA viruses that infect domestic and wildlife hosts. The " classic " pestivirus species, bovine viral diarrhea virus type 1 (BVDV1), bovine viral diarrhea virus type 2 (BVDV2), border disease virus (BDV), and classical swine fever virus (CSFV) were first detected in domestic animals and early differentiation of pestivirus species was based on the domestic animal from which it was isolated. However, it became apparent that these four species were capable of infecting multiple domestic and free-ranging host species. In addition, emerging/putative species of pestivirus, such as pronghorn virus and giraffe virus, were isolated exclusively from wildlife species. The significant economic cost of the infection of domestic species with pestiviruses is well documented but the impact of pestivirus infections on wildlife species is less well studied. Early reports of the isolation of pestiviruses from wildlife were treated as incidental findings. As eradication efforts for CSFV, BVDV1, and BVDV2 proceed around the world, concerns have been raised that wildlife species may act as reservoirs for pestiviruses. Data indicate that CSFV-infected Eurasian wild boar (Sus scrofa) pose a considerable threat to eradication programs in domestic swine. This has led to the implementation of CSFV control strategies in wild boar that combine detection, culling (with cooperation of hunters), and vaccination as detailed in the chapter by Moennig in this volume. Additionally, the chapter by Rossi et al. details the design and use of oral vaccines in wild boar populations. The possibility of free-ranging cervids, small wild ruminants, and rabbits to be reservoirs for BVDV1 and BVDV2 is less clear. Viral detection and serological surveillance both indicate that multiple species of wild ruminants are susceptible to BVDV1 and BVDV2 infection as reported in the chapter by Wolff et al. Epidemiological data indicate that in North America, BVDV1 and BVDV2 infections have become established in wild ruminant populations, and that persistently infected animals are present in these populations as described for white-tailed deer in the chapter by Passler et al. However, to date, evidence demonstrating the introduction of pestiviruses into naïve cattle herds by exposure to wildlife is limited. In Europe, several free-ranging species have been investigated for the potential to be reservoir hosts for BVDV, and the chapters by Larska and Grant et al. discuss the potential for reindeer and rabbits as vectors for the reintroduction of BVDV1 into naive cattle herds. While …