Association of HIV and <i>Mtb</i> infection among household contacts in East and Southern Africa

<sec><title>BACKGROUND</title>Understanding the association of HIV and antiretroviral therapy (ART) status with <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>) transmission dynamics is crucial, particularly in the context of universal ART access.</sec><sec><title>METHODS</title>This cross-sectional analysis included adults with microbiologically confirmed pulmonary TB (medium/high Xpert MTB/Rif) and their household contacts (≥10 years) from Mozambique, Zimbabwe, and Tanzania (2021-2023). Mixed-effects logistic regression assessed associations between TB patients' HIV/ART status and household interferon-gamma release assay (IGRA) positivity.</sec><sec><title>RESULTS</title>A total of 1,923 household contacts of 907 persons with TB were analysed. A third of persons with TB were diagnosed with HIV at the time of TB diagnosis. Overall, 46% of household contacts were IGRA positive at baseline. Household contacts exposed to ART-treated people living with HIV (PLHIV) exhibited high IGRA positivity levels compared with those exposed to PLHIV not on ART (adjusted odds ratio [aOR] 1.88; 95% confidence interval [CI]: 1.17-3.02). Odds for contacts of ART-treated PLHIV was similar to the odds observed in contacts of HIV-negative individuals (aOR 2.21; 95% CI: 1.45-3.36).</sec><sec><title>DISCUSSION</title>In a selected population of people with TB with a medium to high bacillary burden measured by Xpert MTB/Rif, PLHIV while on ART exhibited increased <i>Mtb</i> transmission, comparable with the levels of HIV uninfected.</sec>.