With one quarter of the global tuberculosis cases found in India, a first of its kind survey has shown among all TB patients tested, MDR-TB rate was 6.19% with 2.84% among new and 11.60% among previously treated TB patients.

Any isoniazid resistance among new and previously treated TB patients was 11.06% and 25.09%, respectively. Any drug resistance among new TB patients was 22.54%, with 36.82% among previously treated TB patients and 28.02% among all patients.

Results of this largest and first-ever National Drug Resistant Survey conducted by any country in the world also showed there was negligible rifampicin mono-resistance in the survey and isoniazid resistance was invariably associated with rifampicin resistance. Any pyrazinamide resistance was 6.95% and 8.77% among new and previously treated TB patients, respectively. Among MDR-TB patients, additional resistance to any fluoroquinolone was 21% and any second line drug resistance was 3.84%. Among MDR-TB patients, XDR-TB rate was 1.3%.

A total of 5280 sputum smear-positive pulmonary TB patients (3240 new and 2040 (previously treated) diagnosed at the designated microscopy centres (DMCs) of RNTCP were enrolled in the survey.

There were wide variations in the state-wise levels of drug resistance, highlighting that national level estimates tends to mask the local and focal epidemics that need to be addressed with specific interventions, the survey has said.

With a population of 1.32 billion, India has the highest burden of tuberculosis (TB) and drug-resistant TB (DR-TB) in the world.

The Survey has recommended setting up and strengthening drug resistance surveillance including using state of art next generation sequencing. This will provide the programme with the trends of drug resistance, transmission patterns and mapping of hot spots in different states for better understanding of molecular epidemiology for TB surveillance  and strengthening epidemiologic intelligence for specific interventions based on local epidemiological profile.

India has more new tuberculosis (TB) patients annually than any other country globally, contributing to 27% of the worldÂs TB burden. About 2.79 million TB patients are estimated to be added annually. The Revised National Tuberculosis Control Programme (RNTCP) notified around 1.94 million TB patients in 2016.

As per the Global TB Report 2017, worldwide approximately 4.1% of new TB patients and 19% of previously treated TB patients have multidrug resistant-TB (MDR-TB), i.e. TB resistant to at least two of the first-line drugs  isoniazid and rifampicin. Extensively drug-resistant TB (XDR-TB), defined as MDR-TB with additional resistance to at least one fluoroquinolone and one second line injectable drug, has been reported by 123 countries.

The proportion of XDR-TB among MDR-TB patients is 6.2% worldwide. The estimated number of MDR/rifampicin resistant (RR)-TB in India is 147 000, accounting for one fourth of the global burden of MDR/RR-TB.

India initiated the programmatic management of drug resistant TB (PMDT) in 2007 to address the emerging problem of drug resistant-TB (DR-TB), and the national PMDT scale-up was achieved by March 2013. The treatment success rate among MDR-TB patients in India is consistently about 46% and the death rate is around 20%, as against the global level of treatment success rate of 52% and death rate of 17%. High rates of treatment failure and deaths are associated with fluoroquinolone resistance in the Indian cohort of MDR-TB patients.