The aim of this study was to determine the frequency of positive herds (foci) and seropositive bovine females for brucellosis in the state of Roraima, Northern region of Brazil, as well as to identify risk factors. Data from the Agency of Agricultural Protection in the state, collected from its four microregions during the January 2007 to July 2009 period, were used. During this period, 387 herds were examined, and 9,087 adult bovine female sera were submitted to the serological diagnosis of brucellosis. For risk factor analysis the multiple logistic regression was used. A herd was considered focus when presented at least one seropositive animal. Of the herds investigated, 106 (27.4%) had at least one seropositive animal, and of the animals examined, 369 (4.1%) were seropositive. Risk factors identified were: herd size larger than 51 animals (odds ratio = 1.87; p = 0.015) and pasture rental (odds ratio = 2.20; p = 0.003). It is suggested that efforts must be concentrated on the intensification of heifer vaccination in the State of Roraima in order to reach a prevalence value compatible with actions of test and sacrifice of animals.
Brucella abortus; bovine; frequency; risk factors; epidemiology (control)