Evaluation of a rapid serological chromatographic immunoassay for the diagnosis of pulmonary tuberculosis in Accra, Ghana

Abstract

Advances in serologic assays for tuberculosis (TB) have made serology an attractive surveillance tool. The sensitivity, specificity, and predictive value of these new assays have been well established. We employed an immunochromatographic serodiagnostic test for detecting antibodies (immunoglobulin [Ig] G, IgA, and IgM) specific for mycobacteria-specific antigen 60 (A60) in the serum of suspected TB patients (n=310) attending the Chest Clinic of the Korle-Bu Teaching Hospital, Accra, Ghana. Compared to the gold standard, sputum culture, the performance indexes of the test kit indicated a sensitivity of 80% and a specificity of 98.2%, respectively. The positive predictive value and the likelihood ratios for positive and negative results were 96.6, 44.4, and 0.2%, respectively, when compared to sputum culture. Our results suggest that the serodiagnostic test kit may be a valuable tool for the diagnosis of TB, and can provide simple and satisfactory results, particularly in cases in which TB is clinically difficult to diagnose by the usual clinical and laboratory tests.