Triage Test for All Oral DR-TB Regimen (TRiAD Study)

A Phase 4 operational study to assess the effectiveness, feasibility, acceptability, and cost effectiveness of the GeneXpert MTB/XDR (Xpert XDR; Cepheid) assay for rapid triage-and-treatment of DR-TB-A multi-centre, multi-country prospective cohort study

The TriAD study is a multi-center, multi-country Prospective Pragmatic Cohort study assessing the effectiveness, feasibility, acceptability, and cost-effectiveness of implementing the Xpert MTB/XDR (Xpert XDR; Cepheid) assay for rapid triage-and-treatment with short, all- oral drug resistant tuberculosis (DR-TB) treatment. The proposed study aims to screen approximately 4800 GeneXpert MTB/RIF or Ultra MTB-positive (irrespective of rifampicin resistance status) patients from 9 study sites in South Africa, Nigeria and Ethiopia to enrol 880 rifampicin resistant (RR) and 400 isoniazid mono-resistant (HR) patients over a period of 12-18 months. The Xpert XDR assay, a rapid genotypic test, will be implemented as a reflex test to detect resistance to isoniazid, fluoroquinolones and second-line injectable agents to provide rapid genotypic susceptibility testing for DR-TB detection. Patients that test positive for Mycobacterium tuberculosis with rifampicin resistance will be enrolled in Cohort 1 (n=880). Patients that test positive for Mycobacterium tuberculosis that are rifampicin susceptible with isoniazid mono-resistance will be enrolled in Cohort 2 (n=400). Results from the Xpert XDR assay will be used to guide selection of appropriate, evidence-based, all-oral DR-TB treatment regimens of shortest possible duration. The tuberculosis molecular bacterial load assay (TB-MBLA) will be used as an adjunct to provide bacillary load monitoring over the course of treatment to assess real-time treatment response. Operational research will provide information about the feasibility, acceptability and cost-effectiveness to inform policies and guidelines for programmatic implementation of the triage-and-treat model.