Usefulness of immunochromatographic detection of antibodies to Mycobacterium tuberculosis as an adjunct to auramine staining for rapid diagnosis of tuberculosis in a low-prevalence setting

A novel immunochromatographic membrane-based assay for the detection of spe cific IgG antibodies to Mycobacterium tuberculosis was evaluated in patient s with active tuberculosis in a low-prevalence population. The sensitivity of the test for detecting active tuberculosis was 41.5% (17/41 patients pos itive); its specificity in a group of patients with other lung diseases was 91.4% (3/35 false positive), while in a group of 47 healthy controls it wa s 100%. The sensitivity of the immunochromatographic test equaled that of a uramine staining, but different subsets of tuberculosis patients were detec ted by the two tests. The suboptimal sensitivity of this immunochromatograp hic test implies that, even though it could be a useful adjunct, it cannot be a replacement for the diagnosis of tuberculosis by other microbiological methods along with clinical and radiological data.