Evaluating transmission of bovine viral diarrhea virus to cattle by exposure to carcasses of persistently infected white-tailed deer (Odocoileus Virginianus)


Infections with bovine viral diarrhea virus (BVDV) clinically analogous to cattle are described in white-tailed deer (Odocoileus virginianus), but the epidemiologic role of persistently infected (PI) white-tailed deer is unknown. Persistently infected white-tailed deer shed BVDV, maintaining BVDV in groups of deer. Survival of PI white-tailed deer is reduced, and clinically ill or dead PI deer may be a source of BVDV. This study sought to determine of BVDV transmission could occur when cattle come in cotact with carcasses of PI white-tailed deer. In two trials, performed in Auburn, Alabama, during November and December 2009, steers were exposed to the carcass of PI fawn A (BVDV2) or PI fawn B (BVDV1). Trials were designed with consideration of the influence of contact networks on disease epidemiology, and only one steer from each group was seperated into a pen with thte carcass. The number of contacts with the carcass was monitored. Following 8 hours, the single steer was commingled with four other steers for 28 days. Animals were tested for BVDV infection. Controls included one steer inoculated intranasally with spleen-homogenate from fawn B. Steers in both trials repeatedly contacted the carcass, but BVDV transmission did not occur. The intranasally inoculated control for trail A and the intravenously inoculated control for trial B became viremic and seroconverted. Although both PI carcasses were potentially infectious and steers made repeated contact, transmission of BVDV did not occur in this model.