Prevalence and risk factors of Brucella infection in sheep and goats in the Sistan region by PCR method

Brucellosis is an anthropozoonotic disease. In addition to abortion and economic losses for livestock farmers, brucellosis is also important in terms of public health. In this study, the epidemiology and prevalence of Brucella infection in sheep and goats in the Sistan region were investigated by PCR method. A total of 150 animals, including 92 sheep and 58 goats, were selected from different regions of Sistan, including five counties. Blood was taken from the animals through the jugular vein. The variables of counties, age, sex, and species of livestock, and for female animals, history of abortion, and pregnancy status were recorded by a questionnaire. After the separation of serum from blood, the sera were stored at -20°C for further experiments. Then all sera were tested by PCR for detection of Brucella genus and then positive samples were tested for detection of Brucella melitensis. Out of 150 samples, infection with Brucella genus bacteria were detected in 17 (11%) samples. Also, all samples were positive for Brucella belonging to the melitensis species. In the present study, the prevalence of brucellosis in animals that had a history of abortion (57%) was significantly higher than that in animals which did not have such a history (8%) (P=0.003). It was also found that the prevalence of brucellosis in animals less than one year of age, in animals aged 1 to 2 years, and in animals over 2 years of age was 0%, 20% and 23%, respectively, which shows that the prevalence of brucellosis increases with age.