Epidemiological situation of bovine brucellosis in the State of Mato Grosso do Sul, Brazil

A study to characterize the epidemiological status of bovine brucellosis in the State of Mato Grosso do Sul was carried out. The State was divided in three regions: beef cattle Pantanal, beef cattle Plateau, and dairy cattle Plateau. Herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 14,849 serum samples from 1,004 herds were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as clinical signs that could be associated with the brucellosis infection. The serum samples were tested for antibodies against Brucella spp. by the Rose-Bengal test. The herd was considered positive if at least one animal was positive. The prevalence of infected herds in the State was 41.5% [36.5-44.7%]. The prevalence of infected herds in the regions were, respectively: 40.6% [35.8-45.5%] for beef cattle Plateau, 59.0% [52.8-64.9%] for beef cattle Pantanal, and 33.1% [28.4-38.1%] for dairy cattle Plateau. The risk factors (odds ratio, OR) associated with the presence of the infection were: herd size larger than 500 cows (OR = 2.46 [1.81-3.34]), birth of weak calf (OR = 1.20 [0.87-1.65]), and use of artificial insemination (OR = 0.71 [0.50-1.01]).