At a glance
- Drug-resistant TB is harder to diagnose, more expensive to treat, and undermines efforts to eliminate TB.
- To address this growing challenge, CDC launched a groundbreaking initiative to enhance drug-resistant TB surveillance and outbreak response through genomic sequencing, paving the way for improved diagnostics, effective treatment, and reduced spread across borders.
A global health crisis unfolds
India has the highest burden of drug-resistant TB in the world, accounting for 27% of the global cases. Drug-resistant TB develops when the antibiotics used to treat TB are misused or mismanaged. The emergence of drug-resistant TB now found in every country poses a significant threat to eliminating TB in the U.S. and worldwide.
Existing surveillance systems face several limitations. These include inadequate data collection, underreporting of cases, inconsistent geographic coverage, outdated technology, lack of real-time data, and limited resources. These factors make it difficult to accurately detect drug-resistant TB, leading to ineffective treatment and fueling the spread of disease. It is critical to strengthen laboratory capacity to identify resistance and expand access to testing. This will help determine if a medicine will be effective against a disease.
Pioneering next-generation sequencing
Genomic sequences are crucial for effectively responding to TB outbreaks. Next-generation sequencing has emerged as a powerful tool for rapidly and accurately detecting mutations associated with drug resistance. However, access to this technology has remained limited in high-burden countries, like India.
Next-generation sequencing provides critical insights into drug resistance patterns, identifies transmission clusters, and evaluates the effectiveness of new treatments.
CDC partnered with India's Ministry of Health and Family Welfare, the Central TB Division, and the National Institute for Research in Tuberculosis (NIRT) in Chennai, India, to establish a next-generation sequencing-based surveillance network and build workforce capacity to detect, respond to, and prevent drug-resistant TB. This project aimed to evaluate the effectiveness of this advanced laboratory method and train the National TB Elimination Program to perform next-generation sequencing, increasing sustainability.
Building a national resource for drug resistance
After successfully introducing and piloting sequencing for drug-resistant TB surveillance in 2020, CDC supported partners to culture and sequence over 2,200 TB samples from 90% of Indian states and 50% of union territories. This effort led to the creation of India's first national drug-resistant TB sequencing database and analytics pipeline, providing invaluable data for tracking and managing drug resistance patterns.
Through this collaboration, CDC also contributed to the development of a national associated with drug-resistant TB, most recently updated in 2024. The catalogue marks the first country-specific reference of its kind, modeling a global catalog for interpreting mutations for resistance to 15 TB drugs. The catalogue also serves as a vital reference for interpreting resistance patterns and guides the development of novel diagnostics and treatment regimens for drug-resistant TB.
This initiative has enhanced the ability to identify drug-resistant TB clusters and understand the geographic distribution of mutations, ultimately informing effective treatment strategies to improve patient outcomes. The introduction of next-generation sequencing has significantly improved the detection and surveillance of drug-resistant TB in India and beyond.
Protecting American communities
India's significant steps to reduce drug-resistant TB are crucial for protecting its nation and preventing the global spread of this highly infectious disease. Over 400,000 people develop drug-resistant TB each year, and 60% of people remain undiagnosed and untreated. This situation creates a significant risk for widespread outbreaks and a potential resurgence of the disease in the U.S.
Since drug-resistant TB can spread through the air and easily cross borders through international travel and migration, global drug-resistant TB threatens to erase decades of U.S. progress in TB control and antimicrobial resistance. By strengthening India's TB efforts, the U.S. stops costly and deadly outbreaks at their source, preventing TB from coming to the U.S. and disrupting American lives and livelihoods.
The average cost to treat TB increases with greater resistance.
The advancements made for drug-resistant TB surveillance in a high-burden country like India represent a critical step forward in global surveillance and elimination. By strengthening laboratory capacities and enhancing program management of airborne drug-resistant TB, CDC accelerates efforts to eliminate TB in the U.S. and worldwide, ensuring a healthier future for all.