A comparative study of agglutination tests, blood culture & elisa in the laboratory diagnosis of human brucellosis

Introduction: Brucellosis is one of the important causes of Pyrexia of Unknown Origin (PUO) in endemic areas. The present study was carried out to compare the diagnostic efficacy of Agglutination tests, Blood culture & ELISA in the diagnosis of human brucellosis in cases of Pyrexia of Unknown Origin. Material & Methods: This descriptive study included 42 patients clinically diagnosed with PUO & were investigated for brucellosis and 42 age and sex matched healthy controls. Statistical analysis was done to determine and compare the sensitivity, specificity, positive predictive value & negative predictive value of the test methods. Results: Among the 42 cases, none of the blood cultures grew any isolate of Brucella. A total of 7 cases were serologically positive by agglutination tests. 13 of the 42 cases of clinically suspected brucellosis yielded positive results with ELISA (8 were positive for IgM antibodies alone by ELISA, 3 cases exhibited IgM and IgG classes of antibodies together and 2 were positive for IgG class of antibodies alone). None of the samples in the control group had any positive observations. Conclusion: ELISA is the most reliable and rapid method for the diagnosis of brucellosis.