Research Article
David J Wilson, Thomas J Ba
Abstract
Prevalence of Bovine viral diarrhea virus (BVDV) (“detected” test results) among all bovine samples tested at the Utah Veterinary Diagnostic Laboratory from 2008 - 2013 was calculated, and results were compared by age, sex, or breed of the cattle and BVDV diagnostic test methods. Necropsies were tested for BVDV when lesions suggestive of infection were identified. Adults, juveniles and most calves were tested by antigen (Ag) capture ELISA, while fetuses and some calves were tested by real-time reverse transcriptase PCR. Cattle originated from Utah and surrounding states. Chi-square analyses were used to test for significant differences in BVDV prevalence between age, sex, breed and test methods. Bovine viral diarrhea virus was detected in 105/8,975 samples (1.2%), including 22/180 necropsies (12.2%). Detection of BVDV by each test method was: Ag Capture ELISA-skin 79/7,692 (1.0%); Ag Capture ELISA-serum 19/1,195 (1.6%); PCR 7/88 (8.0%). Detection of BVDV by age, sex, breed was: male 5/215 (2.3%); female 9/382 (2.4%); fetus 3/36 (8.3%); calf (1-200 days old) 29/579 (5.0%); juvenile (201-729 days old) 4/183 (2.2%); adult (≥ 730 days old) 4/75 (5.3%); dairy 25/750 (3.3%); beef 26/1,600 (1.6%). There were no significant differences in BVDV detection by age or sex. Necropsied animals (P<0.0001), those tested with PCR (P<0.0001) and dairy breeds (P=0.07), were more likely to be detected with BVDV. When prevalence of BVDV has been reported over the last 20 years, it has focused on the 0.1% prevalence of persistently infected (PI) cattle, but PI cattle are a source of infection for large numbers of herdmates. The 8% prevalence in aborted fetuses and overall prevalence of >1% demonstrates that despite the low reported prevalence of persistently infected cattle, BVDV remains an important bovine disease.