Prevalence and Factors Associated with Cattle Brucellosis in Animal Herds of the Namibe Province in Angola

Abstract

Brucellosis is considered to be one of the most neglected zoonosis worldwide. In Angola data about brucellosis has not been consistently reported to the World Organization for Animal Health. Therefore, the aim of this study was to estimate the seroprevalence of bovine brucellosis and to identify the risk factors associated with this disease. A seroepidemiological survey was undertaken on 1344 cattle from 192 herds between February and December 2012. The testing for brucellosis was performed using the Rose Bengal test (RBT) for serum analysis and a questionnaire was administered to local farmers. After a descriptive approach, Chi-Square Tests of Independence and Spearman correlations were used, followed by logistic regressions tests in order to determine the odds ratio and confidence interval of risk factors associated with brucellosis. Overall, the seroprevalence of brucellosis in animals and herds was 14.96% (CI95%: 4.20-25.71) and 40.10% (CI95%: 29.14-51.06), respectively. A positive correlation was found between the proportion of animals infected per herd and the average number of abortions in those facilities = 0.531, p< 0.001). The risk factors associated with brucellosis seroprevalence were: inadequate facilities for isolation of infected animals (OR = 6.66; CI95%: 1.16-38.34); purpose of production other activity (social representation and economic power) than meat (OR = 3.13; CI95%: 1.07-9.19); abortions (OR = 3.98; CI95%: 1.92-8.28); female infertility and neonatal mortality (OR = 3.07; CI95%: 1.42-6.65). Our data shows that brucellosis prevails in the Namibe province as 40.10 % of farms are infected. The number of abortions is clearly correlated with the number of herds infected. Local veterinary authorities have a fundamental role in what concerns not only the disease control and surveillance but also in the development and implementation of farmers’ educational programmes.