Impact of a community-wide HIV test and treat intervention on population-level tuberculosis transmission in rural Uganda


BACKGROUND: HIV and TB are linked epidemics. We tested whether a community-wide universal HIV testing and treat strategy would reduce population-level TB transmission in the SEARCH trial.
METHODS: SEARCH was 32-community cluster-randomized trial conducted in rural Uganda and Kenya from 2013-2017 (NCT:01864603). Intervention communities received population-level HIV test and treat; control communities received enhanced standard-of-care. We measured incident TB infection in a nested cohort of children and adults ages (>5 years) in in 4 intervention and 5 control communities (8 and 10 parishes, respectively) in Eastern Uganda. All people in the cohort had a negative tuberculin skin test (TST) at baseline (induration <10mm or <5 mm among PWH); the cohort was enriched with PWH. Incident TB infection (primary outcome) was defined as TST conversion from negative to positive one year after baseline TST (2015-2017). Incident TB was compared between arms, adjusted for sampling and participation, and parish-level drivers of incident TB infection and accounting for clustering using Targeted Maximum Likelihood Estimation.
RESULTS: The TST negative cohort was comprised of 3,242 persons in the intervention and 4,125 persons in the control arms; 2,922 (39.7%) were children (5-11 years) and 4,445 (60.3%) youth and adults (ages 12+ years). Within the cohort 53.3% were women, and PWH comprised 16.6% of adults, 1.1% of children. One-year cumulative incidence of TB infections was 16% in the intervention and 22% in the control; the population-level intervention reduced risk of incident TB infection by 27% (aRR of 0.73; 95% CI: 0.58-0.93, one-sided p=0.007). The effect was largest among children aged 5-11 years (Figure 1).
CONCLUSIONS: A universal HIV test and treat intervention reduced incident TB infection, a marker of population-level TB transmission. Investments in community-level HIV interventions have direct impacts on HIV and broader population-level benefits, including reductions in TB.

Figure 1: