Prevalence and associated risk factors for bovine brucellosis in the State of Pernambuco, Brazil

Abstract

This study was conducted to characterize the epidemiology of bovine brucellosis in the state of Pernambuco, Brazil. The state was divided into three regions, and in each region, approximately 300 properties were randomly sampled. From these selected properties, a pre-established number of animals were randomly selected and blood serum samples were obtained. A total of 3,901 animals were selected from 900 properties. For each selected property, an epidemiological questionnaire was administered to assess the type of farming, the animal husbandry practices and the sanitary practices that could be associated with the presence of brucellosis infection. The testing protocol consisted of screening the samples with a buffered acidified plate antigen test and retesting the positive samples with a complement fixation test (CF). One positive animal was enough to define an infected herd. The prevalence rates of infected herds and animals in the state were 4.5% [3.2; 6.4%] and 1.4% [0.7; 2.7%], respectively. By region, the prevalence rates of infected herds and animals, respectively, were as follows: Zona da Mata, 3.3% [1.8; 6.1%] and 1.7% [0.5; 3.0%]; Agreste, 7.4% [4.9; 10.9%] and 1.9% [0.8; 3.0%]; and Sertão, 1.3% [0.5; 3.5%] and 0.7% [0.0; 1.6%]. Flooded pastures (OR = 2.86 [1.37; 6.42]) and the presence of 13 or more females in the herd (3rd quartile) (OR = 2.65 [1.19; 5.89]) were identified as risk factors. The existence of veterinary care emerged as a protective factor against bovine brucellosis in the state of Pernambuco (OR = 0.24 [0.10; 0.58]).