Seroprevalencia de paratuberculosis bovina mediante la prueba de ELISA urea en rodeos de cría y de leche con sospecha de la enfermedad, localizados en la provincia de Buenos Aires, Argentina

The results of 17.747 bovine serum samples belonging to 85 beef herds and 5 dairy herds from 14 localities of Buenos Aires province are presented. ELISA is the diagnostic test of choice in cattle with subclinical paratuberculosis, and addition of urea in this assay improves the efficiency to detect antibodies against Mycobacterium avium subsp. paratuberculosis (MAP). Seroprevalence was estimated based on positive and suspicious sera to urea ELISA. Individual seroprevalence for beef and dairy herds was 5.5 % and 13.6 %, respectively, with an overall herd seroprevalence of 78.8 %. In addition, 425 fecal samples were analyzed by microbiological culture. Mycobacterium avium subsp. paratuberculosis was isolated in 67.6 % of positive, 52.7 % of suspicious and 7 % of negative urea ELISA animals. The positive predictive value of urea ELISA was 0.61, and the negative predictive value was 0.93 using Bayesian statistics. These results are an update to the estimated regional paratuberculosis seroprevalence and confirm the usefulness of urea ELISA in the diagnosis and control of paratuberculosis in cattle.