Comparison of serologic screening tests for brucellosis.

Area of Science:

• Medical Microbiology
• Immunodiagnostics
• Infectious Diseases

Background:

• Brucellosis remains a significant global public health concern.
• Accurate and efficient diagnostic screening tests are crucial for timely diagnosis and treatment.
• Existing serological tests for brucellosis vary in sensitivity and specificity.

Purpose of the Study:

• To evaluate the diagnostic performance of slide agglutination test (SAT), microagglutination test (MAT), and card agglutination test (CAT) for human brucellosis.
• To compare these screening tests against the gold standard tube agglutination test (TAT).
• To determine the most effective screening strategy for brucellosis diagnosis.

Main Methods:

• Two reference laboratories conducted comparative analyses of SAT, MAT, and CAT against TAT.
• A total of 1,253 serum samples were tested across both laboratories using TAT.
• Specific sample sizes were tested for SAT (1,270 and 1,261), CAT (1,155), and MAT (187) in conjunction with TAT.

Main Results:

• Sensitivities compared to TAT (≥160) were: SAT (97-100%), CAT (90%), MAT (88%).
• Specificities were: SAT (88-89%), CAT (98%), MAT (88%).
• CAT and MAT demonstrated higher specificity, particularly valuable in low-prevalence populations.

Conclusions:

• Card agglutination test (CAT) and microagglutination test (MAT) are recommended as preferred screening tests for human brucellosis due to their high specificity.
• The choice between CAT and MAT depends on testing volume and frequency.
• All reactive samples from CAT and MAT screening should be confirmed using the tube agglutination test (TAT).