Background
Mycobacterium tuberculosis (Mtb) infection is inferred from positive
Methods
A community-based case-control design was used to systematically screen and identify adults living with HIV (HIV+), aged 35-60 years, who met stringent study criteria, and then longitudinally followed up for repeat IGRA and TST testing. Participants had no history of TB despite living in TB hyper-endemic environments in Cape Town, South Africa with a provincial incidence of 681/100,000. Mtb-specific antibodies were measured using ELISA and Luminex. Findings: We identified 48/286 (17%) individuals who tested persistently negative for Mtb-specific T-cell immunoreactivity (three negative Quantiferon