Case-control study on risk factors associated with brucellosis in aborted cattle of Jimma zone, Ethiopia

Brucellosis is one of the most important causes of abortion in cattle resulting in significant economic losses and public health concerns in the developing countries. A case-control study was conducted from October 2016 to October 2017 to investigate risk factors of brucellosis in aborted cattle in Jimma zone. During the study period, 141 cases and 282 controls were selected to assess and compare the presence of anti-Brucella antibodies between cases and controls. Cattle that had experienced abortion were defined as cases, whereas controls were cattle that had no record of abortion. Sera samples were collected from both cases and control cattle groups for laboratory tests (serological test). The existence of the anti-Brucella antibodes in serum samples was first tested by the Rose Bengal Plate test, and the all positive samples were confirmed using the complement fixation test. An overall of 4.02% seroprevalence of brucellosis was recorded in the study areas. Antibody against Brucella organism was higher among cases (6.38%) than controls (2.84%). Multivariable logistic regression analysis identified age (OR 14.16, CI= 2.91-28.84), breed (OR 5.36, CI= 1.76-11.33), herd size (OR 11.82, CI= 1.31-16.17) and species composition (OR 5.10, CI=1.49-13.43) as risk factors (p < 0.05) for Brucella seropositivity. This study documented the occurrence of cattle brucellosis in study areas. Thus, applicable control methods and creating public awareness on the zoonotic transmission of brucellosis should be conducted. Moreover, further study considering more causes should be carried out to identify the specific causes of abortion in cattle for the preparation of the appropriate vaccine.