Limitations of the standard agglutination test for detecting patients with Brucella melitensis bacteremia.

The sensitivity of the standard agglutination test (SAT) for detecting brucellosis was determined in 264 Israeli patients from whom a positive blood culture for Brucella melitensis and serology were obtained within ± 1 week. A SAT titer ≥1:160 had a diagnostic sensitivity of 91.7%, whereas raising the cutoff to ≥1:320, as recommended to decrease false-positive rates in endemic areas, reduced the sensitivity to 82.6%. Physicians working in regions endemic for brucellosis should be aware of the limitations of the SAT for detecting patients with the disease.