Seroepidemiological study of Johne's-disease in dairy cattle in Umbria, Italy

A total of 788 serum samples from dairy cattle in Umbria, Italy, were tested for the presence of antibodies to Mycobacterium avium subspecies paratuberculosis (Map) using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The sampled animals came from 19 herds representative of the central area of the Umbria county (Perugia and Assisi districts). Using the manufacturer suggested cut-off for a positive test, 44 animals (5.6%) were positive. Using the sensitivity and specificity claimed by the manufacturer of the ELISA kit, the true prevalence in Umbria dairy cattle overall was calculated as 9.7% (99% CI, 7.0%, 12.4%).