Feasibility of tuberculosis drug-induced liver injury screening under programme settings in Southern India.

BACKGROUND: Anti-TB drug-induced liver injury (AT-DILI) is an important treatment-related adverse event. The National TB Elimination Programme (NTEP) recommends baseline liver function testing (LFT), but systematic follow-up monitoring remains fragmented. OBJECTIVE: To assess the operational feasibility of implementing a screening cascade among persons with TB (PwTB) at high risk for AT-DILI within routine NTEP services. METHODS: Co-designed implementation research was conducted in three districts of Tamil Nadu between July and December 2025 among adults with drug-sensitive tuberculosis (TB). Persons at high risk were identified using predefined criteria. Feasibility was assessed in implementation terms, focusing on coverage of risk assessment, adherence to the screening cascade, and timeliness of follow-up testing and clinical action. RESULTS: Of 2,258 PwTB, 52.3% (n = 1,158) were at risk for AT-DILI. Among them, 71.2% (n = 840) underwent baseline LFT testing and 53.9% (n = 637) completed follow-up LFT within 30 days. Eighteen PwTB developed AT-DILI (1.5% incidence under programme conditions) reflecting burden with incomplete follow-up rather than true population burden. CONCLUSION: Implementation of an AT-DILI screening cascade within routine NTEP services was partially feasible. Risk identification was operationally achievable, but baseline and follow-up testing remained suboptimal. Gaps in follow-up monitoring and documentation highlight the need for strengthened supervision, accountability, and system support before wider scale-up.