Estimated apparent and true prevalences of paratuberculosis in sheep herds of the Kars Region in Northeastern Turkey

Abstract

Paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis (Map), is one of the most prevalent and costly infectious diseases of livestock, particularly sheep and cattle herds. The aim of this study was to estimate true animal, within-herd, and between-herd prevalence of Map antibodies in sheep herds of the Kars Region in the Northeast part of Turkey. A seroprevalence study was carried out using a commercial ELISA kit. Twenty six sheep herds, non-vaccinated against Map, were randomly selected in different regions and in total 450 sheep aged 24 months and more were sampled. Herds were declared positive if one or more sheep in the herd tested positive for Map antibodies. The animal, within-herd, and between-herd apparent prevalences were calculated as 6.2% (95% CI = 4.3 to 8.8%), 10.2% (95 CI = 7.1 to 14.3%) and 57.7% (95% CI = 38.9 to 74.5%), respectively. True prevalences were estimated by conversion from apparent prevalences via the Rogan-Gladen estimator. True animal, within-herd, and between-herd prevalences were calculated as 8.3% (95% CI = 4.7 to 11.8), 14.6% (95 CI = 8.9 to 20.2) and 90% (95 CI = 59.8 to 120.1), respectively. The results provide useful information regarding the prevalence of Map infection in sheep herds in the Kars Region and will hopefully attract the special attention of veterinarians and promote the establishment of an efficient control programme.