Comparison of PCR and conventional serological methods for detection of Brucella spp. in ovine and caprine blood serum

Document Type: Original Articles


1 DVM graduated, Faculty of veterinary medicine, university of Zabol, Zabol, Iran

2 Department of food hygiene and quality control, Faculty of Veterinary medicine, University of Zabol, Zabol, Iran

3 Department of Pathobiology, Faculty of Veterinary Medicine, University of Zabol, Zabol, Iran

4 Sistan and Baluchestan provincial veterinary service, Iranian veterinary organization, Zahedan, Iran

5 MSc in Genetics, stuff in Faculty of Veterinary Medicine, University of Zabol, Zabol, Iran


Brucellosis is an anthropozoonotic disease. Infection of livestock with Brucella is endemic in most parts of Iran. Sistan and Baluchestan is bordered to the east by Afghanistan and Pakistan countries. The high prevalence of brucellosis in livestock in the eastern neighboring countries can cause transmission of the disease to within this province. This research was conducted to determine the prevalence of brucellosis in small ruminants in the Sistan region of Iran. Comparison of serological and molecular tests for detection of brucellosis was also another aim behind this research. Blood samples were taken from 150 randomly selected sheep and goats and sera were separated. All sera were analyzed by serological (Wright and 2-ME) and molecular (Polymerase Chain Reaction (PCR)) tests. Serological tests were carried out according to the instructions of the Iranian Veterinary Organization The degree of agreement between serological tests and PCR was determined by kappa value. In this study, 17 cases (11.3%) were identified positive by PCR method. Wright and 2-ME tests had the highest agreement with PCR respectively in Titers ≥2/80 and ≥2/40. The results of this study show that the prevalence of brucellosis in sheep and goats of Sistan region is more than most other parts of Iran and this is important in terms of public health. It is suggested that brucellosis vaccination coverage in livestock be increased in this area and people in Sistan region must be notified about methods for preventing brucellosis. Also, further studies to compare conventional serologic tests with gold standard test are recommended.