Brian Lee Vander Ley
Date of this Version
Carlson JM. Environmental sampling techniques for herd-level surveillance of Bovine Viral Diarrhea Virus. 2019.
Control of Bovine Viral Diarrhea Virus (BVDV) relies on resource-intensive individual animal sampling to detect and remove persistently infected (PI) cattle. Herd-level surveillance tools would be useful for herds with unknown BVDV status and for monitoring herds with BVDV-free status. The overall objective of this thesis is to explore the viability of BVDV surveillance at a herd-level using samples collected without handling individual animals. The first objective was to determine the feasibility of using stable flies as a sampling tool to detect BVDV. The second objective was to determine the feasibility of using drinking water to detect BVDV. To accomplish the first objective, pools of stable flies were produced with various quantities of BVDV-fed and BVDV-free flies and were harvested 1-3 days after being fed blood from BVDV-PI calves. To accomplish the second objective, drinking water samples from pens with and without BVDV-PI calves were collected, processed through centrifugal filtration, and analyzed using RT-PCR. BVDV was consistently detected 1-day post exposure when ≥ 10% of the pooled flies were exposed to BVDV-PI blood. Polymerase chain reaction analysis of filtration concentrated drinking water samples resulted in RT-PCR amplification in pens with confirmed and suspect PI cases. The results of this research indicate that both stable fly and drinking water sampling may be useful surveillance tools to monitor herds for BVDV; however, field-based research is needed to validate these techniques.
Advisor: Brian L. Vander Ley