Caprine Paratuberculosis Seroprevalence and Immune Response to Anti-Mycobacterium avium Subspecies paratuberculosis Vaccination on the Canary Islands, Spain

Paratuberculosis (PTB), caused by <i>Mycobacterium avium</i> subspecies <i>paratuberculosis</i> (MAP), is a chronic disease with economic impact on ruminant farming worldwide. The Canary Islands count with the fourth largest goat population in Spain and are "officially free" of bovine tuberculosis. Twelve farms were included with 2774 serum samples tested by an enzyme-linked immunosorbent assay (ELISA) for detection of anti-MAP antibodies in two sessions. In the first session, an overall apparent prevalence of 18.4% (2.5% up to 61.1%) was obtained. Farms with prevalences (0-10%], (10-20%] and >20% were identified, with differences in seroconversion in the same prevalence group between farms and age ranges. Non-vaccinated (nV) and vaccinated (V) animals were included in the second sampling session. Higher levels of antibodies were detected in V animals older than 12 months, with considerable variations between age ranges and farms. Our results describe the current PTB status of the Canary Islands' goat farming. Furthermore, new insights on the effect of the farm prevalence on seroconversion in V animals are provided, although further studies are needed to evaluate the multiple factors affecting the immune response to anti-MAP vaccination.