Sero-prevalence of camel brucellosis and the associated public health risks in Kereyu pastoral area of Oromia Region, Ethiopia

Abstract

Camel brucellosis has been reported in almost all camel-rearing countries in Africa and Asia. A cross sectional study was carried out with the objective of estimating sero-prevalence of brucellosis among camels and identify risk factors associated with sero-positivity to Brucella infection in Kereyu pastoral area of Oromia Region of Ethiopia. A total of 324 sera were collected randomly from apparently healthy camels in Fentale district, East Shewa zone of Oromia Region, Ethiopia. Data related to risk factors such as sex, age, herd size, and herd composition were collected and camel herders were interviewed to assess their awareness about brucellosis on the sampling day. The Rose Bengal plate test (RBPT) was used as a screening test and those RBPT-positive serum samples were further confirmed by complement fixation test (CFT) and competitive enzyme-linked immunosorbent assay (c-ELISA). Out of the collected sera, 21.0% (68/324, 95% CI: 16.4 - 26.2) were positive by the RBPT and of the RBPT-positive samples, 29 (9.0%, 95% CI: 5.9-12.3) and 31 (9.6%, 95% CI: 6.5- 13.0) sera samples were positive by CFT and c-ELISA, respectively. Based on c-ELISA, the animal-and herd-level prevalence in the study area were 9.6% (95% CI: 6.5-13.0) and 35.4% (95% CI: 23.1-43.5), respectively. While sex, age and livestock composition had no significant effect on the prevalence of camel brucellosis (p > 0.05), herd size was the major risk factor for the presence of the disease. Accordingly, camels kept in large herds were 4 times higher at risk for Brucella infection than camels kept under small herd size (OR = 4.024; 95% CI: 1.667-9.716; p < 0.005). Out of 65 camel herders interviewed, 64 had no awareness about the zoonotic importance of brucellosis. This study demonstrated that brucellosis has a moderate occurrence in the study area and may pose health risks to the public. Therefore, there is a need for implementation of better management practices such as regular testing of all animals, typing of infecting strains, culling of positive animals and increasing public awareness on brucellosis.