Epidemiologic characterization of bovine tuberculosis in the state of Espirito Santo, Brazil

A cross-sectional study was carried out between January 2012 and May 2014 to investigate the status of bovine tuberculosis in the state of Espirito Santo. The state was divided into two regions, and in each of them, 300 farms with reproductive activity were randomly selected and considered as the primary sampling units. In the selected farms, a fixed number of female bovines aged over 2 years were randomly selected to undergo a comparative cervical tuberculin test; an epidemiologic questionnaire was also applied. In the state of Espirito Santo, the apparent prevalence of tuberculosis-positive farms was 7.6% (95% confidence interval [CI] = 5.7-9.9). Prevalence at the herd level varied from 4.6% (95% CI = 2.6-7.3) in region 1 to 11.1% (95% CI = 7.7-15.3) in region 2. The apparent prevalence of tuberculosis-positive animals was 0.7% (95% CI = 0.3-1.1) in the state, and the prevalence varied from 0.3% (95% CI = 0.2-0.6) in region 1 to 1.2% (95% CI = 0.3-2.9) in region 2. The risk factors associated with tuberculosis prevalence in Espirito Santo were the number of adult females = 10 (odds ratio [OR] = 2.40; 95% CI = 1.17-5.31) and milking type (milking machine/milking parlor) (OR = 2.88; 95% CI = 1.36-5.86]). The state of Espirito Santo should set up a surveillance system to detect and control bovine tuberculosis, taking into account the importance of dairy farms and animal trade in the state.