Ciência e Tecnologia Veterinária

Seroepidemiology of Ovine Brucellosis in East and West Shewa Zones of Oromia Regional State, Central Ethiopia

Abstract

Endrias Zewdu Gebremedhin

Background

A seroepidemiological study of ovine brucellosis was carried out in Ada’a-Liben, Ambo and Fentale districts of Central Ethiopia from November 2010 to May 2012. A cross-sectional two stage cluster sampling method was used in order to collect 1119 sera samples from 227 flocks. Additionally, a questionnaire survey was conducted to collect information about risk factors. Modified Rose Bengal Plate Test (mRBPT) and Complement Fixation Test (CFT) were used as screening and confirmatory tests, respectively. A logistic regression was used to compute the odd ratios associated with potential risk factors.

Results

Overall, the results revealed that 16.74% (95% Confidence interval [CI]: 11.85, 21.63) and 3.57% [95% CI: 2.49, 4.66] of the tested flocks and animals, respectively, had antibodies against Brucella sp. by CFT. The highest animal level seroprevalence was recorded from Fentale district (4.97%) followed by Ada’a-Liben (3.0%) and Ambo (2.09%) districts. Univariable logistic regression analysis of potential risk factors revealed that district, breed, still birth and neonatal losses were significantly associated with brucella seroprevalence at both individual animal and flock level (P<0.05). Multivariable logistic regression model revealed history of still birth as an independent predictors of seropositivity at individual animal level (adjusted Odds ratio [aOR]=2.55, 95% CI: 1.19, 5.45; P=0.016). Of the variable offered to the multivariable model (district, history of still birth and neonatal losses), none of them were found to be independent predictors of flock level seropositivity (P>0.05).

Conclusions

Ovine brucellosis is endemic at moderately high prevalence in the study areas. History of still birth was significantly associated with ovine brucellosis. Further epidemiological studies that include isolation, biotyping and molecular identification of Brucella sp. and education of people are suggested for better control.