Diagnosis of Cattle Brucellosis by PCR and Serological Methods: Comparison of Diagnostic Tests

Brucellosis is one of the most widespread zoonotic diseases globally. This chronic, contagious disease mainly transmitted from cattle, sheep, goats, pigs and camels through direct contact with blood, placenta, fetuses or uterine secretions or through consumption of contaminated raw animal products such as unpasteurized milk or cheese. Brucellosis is endemic in Iran. The aim of this study was to compare the molecular and serological tests for detection of brucellosis. In a cross-sectional study, the blood specimens were collected from 92 unvaccinated cattle during the time period September 2014 to July, 2015.. The serum samples were aliquoted and stored at −20°C until tested. The brucellosis diagnosis was established by indirect ELISA (iELISA), Rose Bengal, 2ME, Wright and polymerase chain reaction (PCR) method. In this investigation frequency of brucellosis by using Wright, 2ME, Rose Bengal, and iELISA methods were 42.3% (n= 39), 50% (n= 71), 78.2% (n=72), 75% (n=69), 86.2% (n=76), respectively. The specificity and sensitivity of iELISA was higher than the other tests. The 72 positive Rose Bengal samples in PCR were shown to be positive by both genes and 20 negative Rose Bengal samples were shown negative by both samples. Prevention of brucellosis mainly involves education, food quality and personal hygiene. Efforts should be made by responsible authorities. The results of this study showed specificity and sensitivity of indirect ELISA (iELISA) test is more than other methods. So, brucellosis diagnosis using of this test is recommended.