Comparison of serological methods for the diagnosis of brucellosis in water buffalo

Brucellosis is zoonotic and contagious disease caused by the genus Brucella. In buffalo, the disease mainly occurred by Brucella abortus and Brucella melitensis and causes significant economic losses including abortion, loss in milk production and low fertility rates in animals. In this study, serum samples from 320 slaughtered water buffaloes were collected from Ahvaz abattoir during 2014-2015. The collected sera were analyzed for the presence of antibody against brucella by two commercial ELISA kits (IDEXX and ID vet), Wright and Rose Bengal methods and the results were analyzed by Cochran and Mc Nemar test. The results showed that the seroprevalence of brucellosis with Wright method was 1.56%. Significant difference was seen between IDEXX (P0.05). Agreement between Rose Bengal and Wright methods with IDEXX and ID vet ELISA kits was moderate and Kappa statistic for these associations were 0.43 and 0.48 respectively, but agreement between Rose Bengal method with Wright method was very good and Kappa statistic for these association was 1. Agreement between IDEXX and ID vet ELISA kits was very good and Kappa statistic for this association was 0.86. This research showed that the sensitivity of ELISA is more than Rose Bengal and Wright methods, but according to the strategy of disease control in Iran, it is recommended that this method is designed for practical use by determining the cut-off point of the test.