India took a historic step for control and management of multidrug-resistant tuberculosis (MDR-TB) when the Union Health and Family Welfare Minister of Government of India, Dr Harsh Vardhan formally launched the first-ever nationwide anti-TB drug resistance survey (2014-2015) on 6th September 2014 in New Delhi.
This is the largest nationally representative survey on anti-TB drug resistance ever done, covering 100% of the population in India. Never before has any country taken up an anti-TB drug resistance survey of this scale, said Anshu Prakash, Joint Secretary, Ministry of Health and Family Welfare, Government of India.
Globally, China, Brazil and Bangladesh had done anti-TB drug resistance surveys in the past but the number of patients involved and the anti-TB drugs tested for resistance were very few compared to what this nationwide survey envisages. In China and Brazil (in 2006-2007) and Bangladesh (in 2011) surveys, 5 anti-TB drugs were tested for resistance by solid culture method whereas in this Indian survey 13 anti-TB drugs (5 first-line and 8 second-line anti-TB drugs) will be tested by liquid culture method (MGIT 960).
This is the first-ever nationally representative anti-TB drug resistance survey, although some anti-TB drug resistance surveys have been done earlier in India, but at much smaller level and in very small pockets. These small surveys were not really representative at national, state or district levels, informed Dr KS Sachdeva, Additional Director General of Central TB Division, Ministry of Health and Family Welfare, Government of India. He said that, "Five states in India--Orissa, Maharashtra, Gujarat, Tamil Nadu, and Andhra Pradesh had done anti-TB drug resistance surveys earlier in which 2%-3% of new TB cases and 12%-15% of retreatment cases were found to have MDR-TB. But these estimates were not nationally representative of MDR-TB incidence with some states reporting higher MDR-TB cases and some other states reporting lower MDR-TB cases. So undoubtedly we needed to have a nationally representative anti-TB drug resistance survey."
MORE ABOUT THIS FIRST-EVER NATIONAL SURVEY
This national anti-TB drug resistance survey will involve 5214 patients all over the country through 120 TB units. Out of the total 5214 patients, 3233 will be new cases of presumptive MDR-TB and 1991 will be retreatment cases found presumptive for MDR-TB. The survey entails 12,000 liquid cultures, 70,000 tests, establishing 6 new MGIT 960 liquid culture machines, training 600 master trainers and thousands of other staff. Genetic sequencing of isolates to identify associated drug-resistant TB mutations and real-time monitoring system using information communication technology (ICT) are other salient features of this survey.
The survey would provide (i) accurate estimate of MDR-TB; (ii) community level resistance pattern of first and second-line drugs; and (iii) common mutations associated with drug resistance (MDR, pre-XDR, XDR).
Survey results will be used in estimating drug resistance; establishing a surveillance system; designing better regimens based on resistance patterns; genetic sequencing data on common mutations can be used to develop indigenous molecular diagnostics and new drugs; apart from providing other benefits.
Anshu Prakash emphasized that survey results from India will have implications on TB responses not just for our country but also for the entire world as India has highest absolute numbers of MDR-TB and TB patients too.
ANOTHER LANDMARK: DST GUIDED TREATMENT NOW A REALITY
Another major step forward with this survey is that patients diagnosed with drug resistant TB will get treatment as per the report of drug susceptibility testing (DST) done on 13 anti-TB drugs. Dr Jagdish Prasad, Director General of Health Services, Ministry of Health and Family Welfare, Government of India, informed that DST guided proposed regimens are available now after a national consultation of experts.
WHY THIS SURVEY IS IMPORTANT?
Dr Sachdeva said that with 15 odd anti-TB drugs in the Indian market and a large number of patients showing mono- and poly-resistance to anti-TB drugs other than Isoniazid and Rifampicin, there is an urgent need for this type of survey. Currently RNTCP is not addressing resistance patterns other than MDR-TB and XDR-TB and treatment was being provided to those with confirmed MDR-TB and XDR-TB only (instead of DST guided treatment for all). Perhaps outcomes of this national survey will inform the programme to respond adequately to these challenges.
Moreover, resistance patterns have also not been the same. "Globally 9.6% of MDR-TB patients are likely to have XDR-TB and 16.5% of them have resistance to fluoroquinolone drugs (FQ). But in India, although XDR-TB rates among MDR-TB patients are lower than the world average at 4%-7% but level of resistance to fluroquinolone drugs is alarmingly high at 25%-30%. Fluoroquinolone drugs are commonly used for ailments other than TB also such as sore throat, pneumonia, etc. So when people get TB they are likely not to respond to these fluoroquinolone drugs if they have been already exposed to them and become resistant. In such patients we are actually wasting our resources if we are not testing for drug resistance upfront", said Dr Sachdeva.
He also stressed upon the need to address DST for new patients so that new cases of MDR-TB can be diagnosed early and offered suitable treatment based upon the DST results.
MDR-TB BURDEN IN INDIA
India ranks number one accounting for 20% of the TB burden and 25% of the MDR-TB burden at the global level. The mortality associated with MDR-TB is also much higher than drug susceptible TB. With death rates among MDR-TB patients treated under RNTCP in India being 20% as compared to global rate of 14%, the threat of emerging MDR-TB is looming large and needs a multipronged strategy to prevent further spread of MDR-TB. As of now India is able to detect and treat only 40% of the estimated cases of MDR-TB from 122 drug-resistant TB centres across the country. Till June 2014, 447,670 patients presumed to have drug resistance got tested, 53,883 patients received treatment for MDR-TB and 1021 patients received treatment for XDR-TB from RNTCP.
'CLOSE THE TAP': DO NOT FORGET PREVENTION!
Dr Nata Menabde from WHO India said that apart from better diagnostics and treatment regimens, prevention is a critical aspect in reducing MDR-TB burden. Lov Verma, Health Secretary, Ministry of Health and Family Welfare, Government of India, agreed with Menabde that prevention must not be neglected. He said that MDR-TB rates in new TB cases are very alarming and even infants are getting infected with MDR-TB.
CK Mishra, Additional Secretary and Mission Director, National Health Mission, Ministry of Health and Family Welfare, Government of India said that by 2017, rapid molecular tests will be made available in every district of the country.