The impact of a combined TB/HIV intervention on the incidence of TB infection among adolescents and young adults in the HPTN 071 (PopART) trial communities in Zambia and South Africa

Abstract

Background HPTN071 (PopART) was a cluster randomized trial conducted in Zambian and South African (SA) communities, between 2013–2018. The PopART intervention (universal HIV-testing and treatment (UTT) combined with population-level TB symptom screening) was implemented in 14 communities. The TREATS study (2017–2021) was conducted to evaluate the impact of the PopART intervention on TB outcomes. We report on the impact of the combined TB/HIV intervention on the incidence of TB infection in a cohort of adolescents and young adults (AYA) aged 15–24 years. Methods A random sample of AYA was enrolled between July 2018 and July 2019 in 7 intervention vs 7 standard-of-care communities. We collected questionnaire data on risk factors for TB, and blood for measuring TB infection using QuantiFERON (QFT) Plus. AYA were seen at months 12 and 24 with all procedures repeated. Primary outcome was incidence of TB infection comparing intervention and standard-of-care communities. An incident case was defined as a participant with QFT interferon-gamma response of < 0.2 IU/ml plasma (‘negative’) at baseline and a QFT interferon-gamma response of > = 0.7 IU/ml (‘positive’) at follow up. Results We enrolled 4,648 AYA, 2,223 (47.8%) had a negative QFT-plus result at baseline, 1,902 (85.6%) had a follow up blood sample taken at 12 months or 24 months. Among the 1,902 AYA, followed for 2,987 person-years, 213 had incident TB infection giving (7.1 per 100 person-years). TB infection incidence rates were 8.7 per 100 person-years in intervention communities compared to 6.0 per 100 person-years in standard-of-care communities. There was no evidence the intervention reduced the transmission of TB (incidence-rate-ratio of 1.45, 95%CI 0.97–2.15, p = 0.063). Conclusion In our trial setting, we found no evidence that UTT combined with TB active case finding reduced the incidence of TB infection at population level. Our data will inform future modelling work to better understand the population level dynamics of HIV and TB.

Airborne transmission risks of tuberculosis and COVID-19 in schools in South Africa, Switzerland, and Tanzania: Modeling of environmental data

“…Interferon-γ release blood tests (IGRAs) and tuberculin skin tests (TST) are commonly used to diagnose Mtb infection, but school-based surveys are rare. A recent study reported a TB infection incidence rate of 17.1 per 100 person-years among adolescents and young adults in South African communities of a cluster randomized trial [ 63 ]. The prevalence of TB infection among 12 to 18-year-olds is approximately 50% [ 64 ].…”

Comparing patterns of recent and remote Mycobacterium tuberculosis infection determined using the QuantiFERON-TB Gold Plus assay in a high TB burden setting

“…AYP were invited from the community to a health facility (Zambia) or a clinical research site (South Africa) where they were enrolled. Details of the cohort enrollment have been published elsewhere [ 19 ]. The study recruitment period lasted from July 12, 2018 to May 24, 2019.…”

“…AYP were invited from the community to a health facility (Zambia) or a clinical research site (South Africa) where they were enrolled. Details of the cohort enrollment have been published elsewhere [19]. The study recruitment period lasted from July 12, 2018 to May 24, 2019. Study participants aged � 18 years signed an informed consent form prior to enrolment, whilst for participants � 17 years both assent and parental consent were obtained.…”

“…The Tuberculosis Reduction through Expanded Antiretroviral Treatment and TB Screening (TREATS) Study measured the effect of the HPTN 071 (PopART) intervention on several measures of TB burden [17][18][19][20]. TREATS was carried out in 21 communities in Zambia and Western Cape Province, South Africa.…”