Evaluation of Brucellacapt for the diagnosis of human brucellosis

To evaluate the role of Brucellacapt in the diagnosis of human brucellosis, and the correlation with the evolution of the disease.

Twenty-six patients who were admitted to the General Hospital of Albacete (Spain) over a 2-year period and diagnosed with brucellosis were included in the study. One hundred and twenty-three serum samples collected at the time of diagnosis and at intervals during and after treatment were tested by the Coombs test, the standard seroagglutination test (SAT), and Brucellacapt (a new test based on an immunocapture-agglutination technique). To study the specificity of Brucellacapt, sera from 20 patients with other infectious diseases and 20 sera from healthy donors were included in this study.

The sensitivity of the Brucellacapt at the moment of diagnosis was similar to the Coombs test (96 and 100%, respectively), somewhat higher than that of SAT (73%). And the specificity of the Brucellacapt (97.5%) was less than SAT and the Coombs test, that was 100%. The correlation between the classical serological tests and Brucellacapt, showed that titers in Brucellacapt and Coombs test of patients were both similar in a range of 1-2 dilutions. The correlation between Brucellacapt and Coombs (r=0.14) and between Brucellacapt and SAT (r=0.0) did not reach statistical significance. However, the correlation coefficient between Coombs and SAT was r=0.8.

Brucellacapt and Coombs tests showed a similar sensitivity and specificity in the diagnosis of human brucellosis. In addition, as Coombs test, Brucellacapt could help to diagnose patients with long evolution of brucellosis that are not detected with SAT.