Seroprevalence and Risk Factors of Caprine Brucellosis in Khartoum State, Sudan

Abstract

A cross sectional study on caprine brucellosis was conducted in April and May 2012 in Khartoum State, Sudan. A total of 307 goats were selected using multi-stage sampling method. The samples were diagnosed using three serological tests; Rose Bengal plate test (RBPT) as screening test, to detect the brucella serpositivity, and then the positive samples were tested by serum agglutination test (SAT) to measure the antibody titers, and confirmed by competitive Enzyme Linked Immunosorobent Assay (c-ELISA). A questionnaire was also applied to obtain information on the owner characteristics, individual animal characteristics, and management practices. The results showed a seroprevalence of 11.4% (35/307) by RBPT. Out of these 35 positive samples 18 (51.4%) were confirmed by SAT with titer more than 50 IU/ml and 17 (48.6%) were confirmed by c-ELISA. Out of 23 variables screened in the univariable analysis using the Chi-square test, only 11 variables were significant with p-value ≤ 0.25. The variables that had a significant association with seropositivity of caprine brucellosis were: locality (X²=9.33, p-value=0.025), owner age (X²=1.64, p-value=0.199), education level (X²=3.55, p-value=0.169), breed (X²=3.52, p-value=0.061), herd size (X²=6.59, p-value=0.037), history of abortion (X²=2.29, p-value=0.130), history of retained placenta (X²=1.51, p-value=0.218), source of feed (X²=5.56, p-value=0.062), animal origin (X²=5.39, p-value=0.020), veterinary services (X²=2.32, p-value=0.127), and fetal membrane disposal (X²=1.46, p-value=0.227). These factors were considered for further analysis using Forward Logistic Regression analysis, and the final model revealed only three variables with p-values ≤ 0.05. There is a significant higher risk (p-value=0.020) within cross breed, cross breeds had a higher prevalence percentage (13.7%) compared to local breeds (6.3%). A significantly (p-value=0.020) higher prevalence of brucellosis was recorded in animal raised on farms (13.3%) than those purchased from outside (2.0%). Similarly, brucellosis seropositivity significantly increased (p-value=0.026) when owners didn't dispose fetal membranes (21.4%) compared to those who disposed fetal membranes (10.9%). VIII The results of this study showed that caprine brucellosis is distributed throughout all localities of Khartoum State, and this may increase the possibility of spread of the disease in the future. Also the risk factors which play a major role in the spread of the disease should be considered when it comes to implement control and prevention strategies.