Survey of Bovine Brucellosis in Pastoral and Agro-pastoral Production Systems of Borana Zone, Southern Ethiopia and its Public Health Implications

Abstract

A cross-sectional study was carried out to determine the sero-prevalence of bovine brucellosis and associated risk factors as well as to depict its public health implications employing serological and questionnaire surveys. Study subjects were selected by three stage cluster sampling followed by simple random sampling, where individual animals were considered as primary units. A total of 290 blood samples were collected from animals aged 6 months and above comprising 176 females and 114 males. All sera samples were initially screened by Rose Bengal Plate Test (RBPT) and those found positive (n = 17) were re-tested by Compliment Fixation Test (CFT) for further confirmation. Thus, the overall sero-prevalence of brucellosis was 5.9% at 95% CI = [3.2, 8.6] and it ranged from 5.4% (n = 92) in agro-pastoral production system to 6.1% (n = 198) in pastoral production system. The difference between the two production systems revealed no statistically significant difference (p>0.05) although the difference in the prevalence between female 7.4% (n = 176) and male 3.5% (n = 114) subjects was found to be statistically significant (p<0.05). Similarly, statistically significant difference was observed (p<0.05) among age groups, indicating that brucellosis may be associated with an advancing age. Increasing herd size also revealed a corresponding highly significant (p<0.05) association with brucellosis prevalence, implicating that high stocking density may favor the spread of brucellosis in the herd. On the other hand, a history of abortion (p<0.001) and parity (p = 0.05) showed highly significant association with brucellosis prevalence although still birth was not found to be significantly associated with the occurrence of brucellosis. This study has revealed the zoonotic significance of bovine brucellosis in pastoral and agropastoral livestock production systems, which implicated that livestock owners are at a high risk of acquiring the infection and thus improving management and hygienic practices, particularly when handling animals and raising community awareness of the study settings are recommended as critical in curbing the spread of the infection.