Diagnostic value of Brucella ELISA IgG and IgM in bacteremic and non-bacteremic patients with brucellosis

The diagnostic value of Brucella ELISA IgG and IgM has been evaluated in patients with brucellosis. Serum samples and blood cultures were collected from 83 patients with brucellosis. The sera were tested by Brucella ELISA for Brucella IgM and IgG antibodies. All 44 controls were negative for IgG and IgM. Brucella melitensis was isolated from blood cultures of 30/83 (36.1%) patients. Among the 30 bacteremic patients, 24 (80%) had an increased IgM titer of > or = 200. Of the 53 non-bacteremic patients, 41 had IgM titer > or = 200, while 22 had IgG titer of > or = 1,600. The ELISA IgM and IgG tests achieved a specificity and sensitivity of 100% and 96% respectively, while the positive and negative predictive values were 100% and 94% respectively. The Brucella ELISA is a reliable and sensitive test in the diagnosis of brucellosis. The test is rapid, easy to perform and can be automated.