India faces critical challenge as WHO lists rifampicin-resistant TB as major threat

The World Health Organization (WHO) has updated its 2024 Bacterial Priority Pathogens List (BPPL), designating rifampicin-resistant tuberculosis (TB) as a critical threat. This is the first time it has been included in the category, highlighting its severe impact, particularly in low- and middle-income countries like India.

India carries a significant burden of drug-resistant TB (DR-TB). The BPPL, which identifies 15 families of antibiotic-resistant bacteria, is designed to guide the development of essential treatments to combat antimicrobial resistance (AMR). The list, last released in 2017, groups these bacteria into critical, high, and medium categories based on their threat levels.

For India, this development is significant. According to the WHO’s Global TB Report 2023, India has the highest DR-TB burden in the world, with an estimated 110,000 new cases emerging annually. However, in 2022, only 64,411 cases were diagnosed and reported, highlighting a gap in detection and reporting.

DR-TB occurs when TB bacteria become resistant to at least one of the first-line anti-TB drugs, such as rifampicin (R) and isoniazid (H). The rifampicin-resistant variant of Mycobacterium TB has been categorised as critical due to its ability to transfer resistance genes, the severity of infections it causes, and its significant global burden, particularly in low- and middle-income countries.

To address this challenge, the Indian government issued guidelines in 2018 mandating that all notified TB cases be checked for resistance to rifampicin. The WHO emphasises the importance of bacteriological testing through methods such as sputum smear microscopy, culture, lateral flow urine lipoarabinomannan (LF-LAM) assays, or rapid molecular diagnostics. These tests are crucial for detecting resistance to both first-line and second-line anti-TB drugs and ensuring appropriate treatment.

However, according to the India TB Report 2023, only 51% of the 24.2 lakh patients notified to the National TB Elimination Programme in 2022 were bacteriologically tested. Furthermore, only 76% of these patients were tested for rifampicin resistance.

“Drug-resistant TB is a major public health challenge in India, and the inclusion of the rifampicin-resistant strain in the 2024 BPPL holds significance. Beyond rifampicin, it is critical to identify the resistance profile to prescribe the appropriate treatment,” said Dr Vikas Oswal, National technical expert, National TB Elimination Programme.

In December 2022, the WHO updated its Consolidated Guidelines on Tuberculosis (TB), Module 4: Treatment – Drug-Resistant Tuberculosis Treatment. The update recommended using a 6-month treatment regimen composed of bedaquiline, pretomanid, linezolid (600 mg), and moxifloxacin (BPaLM) instead of the 9-month or longer (18-month) regimens for MDR/RR-TB patients. India is yet to implement this recommendation.

“On the treatment side, new regimens recommended by the WHO, such as BPaL, can cure patients in a shorter duration with fewer pills and side effects. Patients on these regimens have had treatment success rates similar to those with drug-sensitive TB. By making this regimen available to all DR-TB patients in India, we can significantly improve their quality of life and the country’s chances of defeating DR-TB,” said Dr Oswal.