Infecção pelo alphaherpesvírus bovino tipo 1, vírus da diarreia viral bovina e Brucella abortus em fêmeas bovinas de corte abatidas em um frigorífico sob SIF no Estado do Maranhão

Abstract

The present study aimed to estimate the apparent prevalence and true prevalence of reactive animals for BoHV-1, BVDV and Brucella abortus. Blood samples from 650 beef cows from 14 random batches from municipalities in the state of Maranhão were collected in a slaughterhouse registered at the Federal Inspection Service between July / 2015 and June / 2016. For the diagnosis of Brucella abortus the serum agglutination tests with Acidified Buffered Acid and 2-Mercaptoethanol were used. In order to investigate the antibodies against BoHV-1 and BVDV, 364 samples from 13 batches chosen by lottery were analyzed using the IDEXX IBR gb X3 Ab and IDEXX BVDV Total Ab kits. Of the 650 samples analyzed, 1.23% (8/650) were positive for Brucellosis. Of the 14 batches, five contained at least one positive animal. Of the samples analyzed for BVDV, 65.66% (239/364) and 100% of the batches (13/13) were positive. For BoHV-1, 85.99% (313/364) and 100% of batches (13/13) reacted positively. The estimated true prevalence for BVDV and BoHV-1, calculated taking into account the specificity and sensitivity reported in the ELISA kits, was estimated at 68.02% and 85.96%, respectively. Only batches No. 4, 7, 8, 10 and 12 presented reactive animals for the three pathogens studied. It was also found that the prevalence variability among the lots found for Brucellosis (s = 6.17) is high and that the prevalence variability among lots found for BVDV (s = 0.244) is higher than that found for BoHV -1 (s = 0.096).