Nearly two months after the Health Ministry set the ambitious target of working towards elimination of tuberculosis by 2025, a study published in The Lancet indicates that India’s TB crisis is set to snowball by 2040 when one in 10 cases could be drug-resistant — both multidrug-resistant TB (or MDR-TB, resistant to more than one of the first-line drugs) and extensively drug-resistant TB (or XDR-TB, also resistant to fluoroquinolones and at least one of the second-line injectable drugs).
Direct transmission will lead to more MDR cases
What is even more alarming is the projection that the increased number of drug-resistant cases will come from direct transmission from infected people to others rather than by strains acquiring resistance to TB drugs during treatment due to inadequate treatment or discontinuation of treatment midway. The study found that “most incident” MDR cases are “not caused” by acquired drug resistance, which will become a “decreasing cause” of drug-resistant TB. The increased availability of drugs to fight drug-sensitive TB has led to the emergence of MDR-TB strains. With an increasing number of MDR-TB cases, there has been a shift in the way people get infected with drug-resistant TB — from strains acquiring drug resistance during treatment to direct transmission of MDR-TB strains from an infected person. The same trend is seen in the case of XDR-TB too. As a result, in high MDR-TB burden countries such as India, improved treatment outcomes in people might only reduce and not eliminate drug-resistant TB. Till 2015, only about 93,000 people with MDR-TB had been diagnosed and put on treatment.
Besides targeting early diagnosis and treatment of those with the disease, India’s TB control programme has identified enhanced interventions to break the transmission cycle of the bacteria in the community. Contact screening of family members and preventive treatment of all children below the age of five who have not developed the disease are already a part of the Revised National Tuberculosis Control Programme, but rarely done. Another important strategy that has to be adopted is making drug-susceptibility testing universal and mandatory. Developing more accurate, cheaper and effective diagnostic tests and improved treatment regimens that are less expensive and of shorter duration will also go a long way in winning the war against the disease.
(Adapted from The Hindu)