Control of bovine brucellosis from 1998 to 2009 in the State of Mato Grosso do Sul, Brazil

Abstract

This study used disease prevalence as an indicator to assess the effectiveness of the bovine brucellosis vaccination program implemented by the state of Mato Grosso do Sul. The state was divided into three regions: Pantanal, Planalto Sul, and Planalto Norte. For each region, a predetermined number of properties was sampled; in each, blood samples were collected from randomly selected cows aged at least 24 months. Sera from animals were subjected to a protocol that called for serial testing, with screening and confirmation using the buffered acidified antigen and 2-mercaptoethanol tests, respectively. In each property, a questionnaire was completed in order to identify risk factors associated with the disease. The overall prevalence rates of infected herds and infected animals in the state were 30.6% [27.4; 34.0] and 7.0% [5.6; 8.7], respectively. The regional prevalence rates of infected herds and infected animals were 39.1% and 8.9%, respectively, in Pantanal, 25.3% and 6.1% in Planalto Sul, and 32.1% and 6.4% in Planalto Norte. Bovine brucellosis in the state is associated with the purchase of breeding animals, herd size, and beef and mixed types of enterprise. Thus, Mato Grosso do Sul should reassess its vaccination program in order to improve its effectiveness. The state must also increase education and supervision to encourage producers to test breeding animals for brucellosis before introducing them to their properties.