India has the largest number of tuberculosis (TB) cases in the world, registering 26 percent of of total number. TB is one of the deadliest infectious diseases; two people die every three minutes of TB in the South Asian country.

According to the World Health Organization, 8.6 million people developed TB in 2012 and 1.3 million died of the disease. The rate of new cases has been declining at a yearly rate of two percent over the past decade.

Resistance to drugs is compounding the problem. About 450,000 people contracted drug-resistant (DR) TB in 2012. About half of them live in India, China and Russia. Four-fifths of DR-TB cases are still undetected. There were 170,000 multi-drug resistant (MDR) TB deaths worldwide.

Drug resistant TB can occur as a primary infection or develop during a patient's treatment. India accounted for the greatest increase in MDR-TB with 64,000 new cases in 2012. Here a health worker provides medication to a MDR-TB patient.

A MDR-TB patient in India's northeastern state of Manipur. According to experts DR-TB is man-made - an iatrogenic disease, resulting from the improper treatment of TB.

According to Madhukar Pai of the McGill International TB Center, drug resistance is caused by implementing wrong drug regimens, low quality drugs, scarce monitoring of treatment adherence, patient movement between providers, adding single new drugs to already failing regimens and inadequate use of drug-susceptibility testing.

India provides free TB treatment through the Revised National Tuberculosis Control Program (RNTCP), which reaches 1.5 million patients. But about half of those infected with TB go to the private sector, which is not involved in TB control, experts say.