Serological Diagnosis of Brucellosis

Aim: To present a review and to describe the most widely used laboratory tests for serology diagnosis of brucellosis along with their pros and cons.

Methods: Review the recent literature on brucellosis serology diagnostic tests. The choice of the testing strategy depends on the prevailing brucellosis epidemiological situation and the goal of testing.

Results: The 'gold standard' for the diagnosis of brucellosis is isolation and identification of the causative bacterium, a member of Brucella sp. Isolation of Brucella sp. requires high security laboratory facilities (biological containment level 3), highly skilled personnel, an extended turnaround time for results and it is considered a hazardous procedure. Hence brucellosis is generally diagnosed by detection of an elevated level of antibody in serum or other body fluid. This is a presumptive diagnosis as other microorganisms and perhaps environmental factors can also cause increased antibody levels.

Conclusion: A large number of serological tests for brucellosis have been devised over the 100+ years since its initial isolation, starting with a simple agglutination test and progressing to sophisticated primary binding assays available today. However, no test devised to date is 100% accurate so generally serological diagnosis consists of testing sera by several tests, usually a screening test of high sensitivity, followed by a confirmatory test of high specificity.