Bovine tuberculosis and its risk factors among dairy cattle herds in and around Bahir Dar City, Northwest Ethiopia

Abstract

A cross-sectional study focusing on the prevalence and assessment of the associated risk factors of bovine tuberculosis (BTB) among dairy cattle herds was conducted from 2012 to 2014 in Bahir Dar City and the surrounding districts. Comparative intradermal tuberculin test (CIDT) and interviewer administer questionnaire were used for conducting this study. Animal prevalence of BTB was 3.55% (95% confidence interval (CI): 2.26-4.84) at >=2mm cut-off value and 1.27% (95%CI: 0.49-2.05) at >=4mm cut-off value. Similarly, herd prevalence was 12.5% (95% CI: 7.78-17.2) at >=2mm cut-off value and 5.21 % (95%CI: 2.04-8.38) at >=4mm cut-off value. In a multivariable logistic regression analysis, being cross breed (adjusted OR=3.33, 95%CI: 0.33-34.0) and having poor body condition (adjusted OR=467, 95%CI: 35.9-6086) were identified as animal level risk factors for higher tuberculin reactivity. At herd level increased risk for CIDT positivity was recorded at intensive dairy herds (adjusted OR= 10.8: 95%CI: 1.32-88.1) as compared to smallholder dairy herds. In summary, the present study revealed overall low prevalence of BTB in dairy cattle in the study area. However, comparatively higher proportion of skin reactors recorded at upgraded breeds and intensive dairy herds. This warrants the need for the designing of practically acceptable control strategy.

Keywords: Bovine tuberculosis, Dairy cattle herd, Prevalence, Risk factor