Interpretation of findings and consistency with other studies
TB, infection
INFECTION
Several factors could have contributed to the lack of evidence for impact of the PopART intervention on TB prevalence. First, the TB-specific component of the PopART intervention consisted of systematic TB screening based on TB symptoms. National and subnational TB prevalence surveys have consistently found that a considerable proportion of individuals who have prevalent TB on the day of the survey are identified for diagnostic testing only on the basis of an abnormal X-ray and not based on the TB suggestive symptoms they report [Second, an interim review of the TB symptom screening component of the PopART intervention identified that it was not prioritised by the CHiPs during years 1 to 2 of intervention delivery. Instead, CHiPs focused on offering universal HIV testing and supporting HIV–positive individuals to register for HIV care, because the primary goal of the intervention was to reduce HIV incidence. CHiPs gave more attention to TB symptom screening during years 3 to 4 of intervention delivery, following re-training and enhanced monitoring, but this effort may have been for too short a time to have much impact on population-wide TB incidence and prevalence. Nevertheless, among individuals who participated in the PopART intervention, the percentage who were eligible to provide sputum samples for TB diagnostic testing based on the TB symptoms they reported was around 1%, 1%, and 2%, respectively, across rounds 1 to 3 of intervention delivery in Zambian communities, the proportion who were diagnosed with TB (among all who participated in the intervention) was around 0.08%, 0.08%, and 0.1%, respectively, and in each round approximately 200,000 individuals aged ≥15 years participated. In the third round of intervention delivery in South African communities, the corresponding figures were that around 6% of individuals were eligible to provide sputum samples for TB diagnostic testing based on the TB symptoms they reported, the proportion of all intervention participants who were diagnosed with TB was 0.4%, and around 85,000 individuals aged ≥15 years participated (estimates for rounds 1 to 2 could not be made due to challenges with some aspects of data collection and recording) [Third, we found that TB prevalence was much higher among men than women in the TREATS study communities, consistent with findings from national TB prevalence surveys in Zambia and South Africa [Fourth, by the time of the TREATS TB prevalence survey in 2019 to 2021, HIV testing and ART coverage among HIV–positive individuals was on average similar in communities in the standard-of-care arm (arm C) to those in the PopART intervention arm (arms A and B). In contrast, between mid-2016 and mid-2018, the proportion of HIV–positive individuals who were virally suppressed was on average lower in the standard-of-care arm than in the PopART intervention arms [Fifth, the COVID pandemic disrupted access to TB diagnostic and treatment services during 2020 to 2021, and it also interrupted and delayed the completion of the TB prevalence survey. While this happened across all study communities, it may have reduced the differences among trial arms in terms of TB prevalence.Our findings are consistent with the TREATS co-primary endpoint of the incidence of new infection with 