Comparison of the sensitivity and specifity of modified Rose Bengal and ELISA test in the diagnosis of brucellosis

Brucellosis is a zoonotic disease and is one of the major health problems in our country. Considering its nonspecific symptoms, diagnosis of this disease is often made by laboratory methods. The purpose of the present study was to compare the sensitivity and specificity of ELISA and a relatively new modified Rose Bengal test in the diagnosis of brucellosis.

In this cross-sectional study, blood samples were taken from 162 patients who had been diagnosed by an infectious disease specialist as suspected brucellosis. We used clot tube for serum preparation and anticoagulant tube to prevent coagualation. Serum was used for modified Rose Bengal test and ELISA tests and blood with anticoagulant was used for PCR test, as a gold standard test.

The results of this study showed that modified Rose Bengal test had high sensitivity (94%) and relatively good specificity (70%), compared to PCR. In addition, ELISA test for IgG specific to Brucella antigen also had the same sensitivity and specificity as the modified Rose Bengal test (sensitivity 94% and specificity 71%). In contrast, ELISA test for IgM specific to Brucella antigen, showed high (84%) specificity, but low (65%) sensitivity.

The results of this study showed that the sensitivity and specificity of the modified Rose Bengal test were similar to those of ELISA test for IgG and could be a good alternative to this expensive and complex test in the diagnosis of brucellosis.