New Delhi,Virander S Chauhan(dna): India is home to the largest number of tuberculosis cases in the world. Of the 8.6 million new TB cases in the world every year, 2.3 million reside in India. More than 3,00,000 Indians perish from the disease each year. The large burden of TB cases makes the containment of the epidemic a national priority.
Accurate and rapid diagnosis forms the cornerstone of any effective TB control programme in the world. But unfortunately, in high TB burden countries like India, there are still deficiencies in case-finding tools which have resulted in a huge number of patients being left undiagnosed. In the developed and industrialised world, notable progress has been made in upgrading the speed and accuracy of diagnostic services. But this progress has not reached the countries where TB is a huge public health problem.
Basic TB control has been established as the most cost-effective intervention in controlling the epidemic. India adopted the World Health Organisation’s (WHO) DOTS strategy in 1997. But DOTS alone is not enough. The fact that the disease, which kills one person every 20 seconds, largely depends on a 125-year-old test, an 85-year-old vaccine and drugs that take six months to cure and haven’t changed in over 40 years is appalling.
The present approaches for prevention, diagnosis and treatment of TB are clearly insufficient. The most commonly used diagnosis method, the microscope, detects only half the cases, leaving out a huge number undiagnosed. The BCG vaccine being used does not offer complete protection for children and provides no protection for adults. Inaccurate tests, incorrect medication and lack of adherence to treatment are major obstacles to the reduction of TB cases in India and have given rise to drug-resistant strains of the disease. Serological (blood) tests for TB have been banned in India but are still being used by private diagnostics providers. More than 73 types of serology kits for TB diagnosis are being marketed and produced, mostly in China and India. The market in India for these tests was estimated at a $15 million a year. There is a strong need for stringent enforcement of the ban to completely remove these tests from the market.
The rise of drug-resistant TB strains in India is a major cause for concern. Multi-drug resistant TB (MDR-TB), which is a form of the disease that is resistant to frontline drugs, and extensively drug-resistant TB (XDR-TB), which is also resistant to some second-line drugs pose as a major public health problem in the country. As per the WHO Global Report on Tuberculosis 2014, India accounts for 64,000 MDR-TB cases out of 300,000 cases estimated globally to occur among the notified pulmonary TB cases annually. This can be attributed to the years of inadequate diagnosis and treatment and these forms are difficult to diagnose and much more expensive to treat.
There are very few laboratories to diagnose MDR-TB accurately. With new diagnostic capabilities, including molecular testing, lab workers can diagnose drug-resistant TB in days instead of weeks. MDR, XDR and extremely drug-resistant (XXDR) TB are essentially laboratory based diagnoses. Despite a population of 1.3 billion, India has only 45 laboratories capable of performing Drug Susceptibility Testing (DST). This works out to an abysmally low ratio of 0.2 labs per million populations. China in contrast, with its comparable population, has 249 DST capable laboratories. The extent of the country’s MDR burden will remain unknown till more labs are not opened.
The Revised National Tuberculosis Control Programme (RNTCP) which falls under the Ministry of Health and Family Welfare has developed an innovative strategy termed the National Strategic Plan (2012-2017) which outlines its vision of Universal Access to Quality Diagnosis and Treatment for all TB suspects in India. Under the NSP, the RNTCP with the support from UNITAID, WHO and STOP TB Partnership initiated the RNTCP TB Xpert Project. The project currently provides services for rapid decentralized diagnosis of MDR-TB. Under the project, sites are also implementing innovative mechanism to adopt PPM models to provide diagnosis of TB and DR-TB from the private sector.
Gene Xpert, Line Probe Assays (LPA), Liquid and Solid Cultures are some of the WHO recommended standard tests for accurately diagnosing TB, and anti-TB drug resistance. In order to engage the private sector, IPAQT (Initiative for Promoting Affordable Quality TB Tests) was rolled out in 2013 and the number of labs/private hospitals in the country offering the WHO-approved tests like GeneXpert, Line Probe Assay (LPA) for diagnosing TB disease at a subsidised price has reached 54. Number of TB cases getting diagnosed using Gene Xpert in private sector went up from 500 to 22,210 after the introduction of IPAQT. However, although this is a welcome move, there is a long way to go given the high TB burden in the country. Private doctors are still not aware about IPAQT and that the WHO-endorsed tests are now available at affordable prices.
There is an immediate need for a magnified focus and increase in funding to develop new tools for diagnosis and treatment and expand the use of under-utilised technologies. Timely and accurate diagnosis lies at the foundation of an effective TB programme and the government should take a proactive approach in providing the facilities to cover the whole affected population as soon as possible.
Dr. Virander Singh Chauhan is a leading expert on TB prevention and control. He is Former Director, International Centre for Genetic Engineering and Biotechnology (ICGEB) and Member UGC. He was awarded the Padma Shree in 2012 by the President, for his contribution in the field of Science and Technology.