؊ (0% and 6%, respectively), and at moderate risk for TB development, i.e., U.S. HIV ؉ TST ؉ controls (14% and 10%, respectively). By contrast, more reactivity was detected in the S.A. HIV ؉ control group at higher risk for TB (25% and 45%, respectively). Our data hold promise that antibody detection against MPT51 and echA1 might have adjunctive value in the detection of HIV ؉ smear-negative TB and might reflect increasing Mycobacterium tuberculosis infection activity in asymptomatic HIV ؉ individuals.