On Monday, India added the first new drug in 50 years to its existing cocktail of free medications prescribed under its public health programme to treat the extensively drug-resistant tuberculosis (XDR TB), which defies cure. But adding a new drug, in this case the World Health Organisation-approved bedaquiline, will not stamp out XDR TB unless the health ministry comes down hard on doctors who treat people symptomatically and prescribe TB drugs without diagnosis.
Adding the new drug, however potent, will treat the infection for a while, but at a cost. Even without bedaquiline, treating XDR TB involves giving the patient a cocktail of 12-15 drugs and daily injections that cause toxic side effects. Even when this expensive drug is given for free, many patients stop treatment midway because it needs to be taken daily for 20 months or more, and is too toxic. According to WHO data, globally, less than half of all patients who start MDR-TB therapy are treated successfully.
Like with all microbial resistance, the tuberculosis bacterium develops resistance when the medicines used to treat TB are misused or mismanaged; when patients stop taking medicines before the full course of treatment; when doctors prescribe the wrong medicines, dose or duration; when people do not take their TB drugs regularly; or when a person is directly infected.
Bacteria can evolve very fast — sometimes, in a matter of days — to sidestep the action of a new antibiotic. So, unless unregulated providers are stopped from prescribing wrong drugs and doses, XDR TB cases will continue to rise and it will not be long before the TB bacterium develops resistance to bedaquiline.
India accounts for an estimated 2.2 million of the 8.6 million new cases of tuberculosis that occur globally each year; and the disease kills about 270,000 people annually in India. With the private sector accounting for almost 80% of outpatient care and 60% of inpatient care, where 40% of care is provided by informal and unqualified providers, the challenge before the health ministry is immense. How well it manages will determine how efficiently India fights back the incurable TB.