Tuberculosis (TB) remains the leading cause of infectious disease deaths, particularly among people living with HIV (PWH). Despite being preventable, TB preventive therapy (TPT) uptake is low in high-burden regions like South Africa, where new guidelines have expanded TPT eligibility and introduced shorter, more effective regimens like 3 months of weekly rifapentine and isoniazid (3HP). As differentiated service delivery models for HIV care have proven effective, there is increasing recognition that decentralising TPT delivery may improve coverage and completion. This study explores whether a community-based TPT delivery strategy can enhance uptake and completion of TPT compared with traditional clinic-based services.
We will conduct a household-randomised, non-blinded, controlled trial. Persons eligible for TPT will be recruited from the TB TRIAGE+Trial study, a community-based household TB screening study. Households containing at least one person eligible for TPT will be randomised 1:1 to either community-based TPT or standard-of-care clinic referral for TPT. At enrolment, all participants will be provided with a 2-week supply of TPT in the community. Participants randomised to the community arm will receive the entire course of TPT in a single dispense (12 weeks of 3HP or 6 months of isoniazid, if 3HP is contraindicated). Clinic-arm participants will be referred to their local clinic for the remainder of their course of TPT and will collect TPT refills on the clinic-determined schedule. Our primary outcome is the proportion of participants who complete a course of TPT. Secondary outcomes include overall adherence to TPT, predictors of adherence with TPT, participant satisfaction with the assigned TPT delivery method and adverse events.
The study and its tools were approved by the Human Sciences Research Councils Research Ethics Committee (approval number: 2/25/10/23), based in Pretoria, Gauteng, South Africa, as well as the University of Washington Institutional Review Board (Study 00018448). Study findings will be shared through the community advisory group and local stakeholder meetings, relevant international and local meetings/conferences and peer-reviewed publications.
NCT06214910. Date and version: 3.0, 30 July 2024.
Tuberculosis (TB) remains a significant public health challenge in many African communities, where underreporting and underdiagnosis are prevalent due to barriers in accessing care and inadequate diagnostic tools. This is particularly concerning in hard-to-reach areas with a high burden of TB/HIV co-infection, where missed or delayed diagnoses exacerbate disease transmission, increase mortality and lead to severe economic and health consequences. To address these challenges, it is crucial to evaluate innovative, cost-effective, community-based screening strategies that can improve early detection and linkage to care.
We conduct a prospective, community-based, diagnostic, pragmatic trial in communities of the Butha Buthe District in Lesotho and the Greater Edendale area of Msunduzi Municipality, KwaZulu-Natal in South Africa to compare two strategies for population-based TB screening: computer-aided detection (CAD) technology alone (CAD4TBv7 approach) versus CAD combined with point-of-care C reactive protein (CRP) testing (CAD4TBv7-CRP approach). Following a chest X-ray, CAD produces an abnormality score, which indicates the likelihood of TB. Score thresholds informing the screening logic for both approaches were determined based on the WHO’s target product profile for a TB screening test. CAD scores above a threshold prespecified for the CAD4TBv7 approach indicate confirmatory testing for TB (Xpert MTB/RIF Ultra). For the CAD4TBv7-CRP approach, a CAD score within a predefined window requires the conduct of the second screening test, CRP, while a score above the respective upper threshold is followed by Xpert MTB/RIF Ultra. A CRP result above the selected cut-off also requires a confirmatory TB test. Participants with CAD scores below the (lower) threshold and those with CRP levels below the cut-off are considered screen-negative. The trial aims to compare the yield of detected TB cases and cost-effectiveness between two screening approaches by applying a paired screen-positive design. 20 000 adult participants will be enrolled and will receive a posterior anterior digital chest X-ray which is analysed by CAD software.
The protocol was approved by National Health Research Ethics Committee in Lesotho (NH-REC, ID52-2022), the Human Sciences Research Council Research Ethics Committee (HSRC REC, REC 2/23/09/20) and the Provincial Health Research Committee of the Department of Health of KwaZulu-Natal (KZ_202209_022) in South Africa and from the Swiss Ethics Committee Northwest and Central Switzerland (EKNZ, AO_2022–00044). This manuscript is based on protocol V.4.0, 19 January 2024. Trial findings will be disseminated through peer-reviewed publications, conference presentations and through communication offices of the consortium partners and the project’s website (https://tbtriage.com/).
ClinicalTrials.gov (NCT05526885), South African National Clinical Trials Register (SANCTR; DOH-27-092022-8096).