India is facing an acute shortage of tuberculosis drugs that could threaten the decades-long battle against the deadly disease.

The lives of thousands of tuberculosis patients in India, who accounts for one-fifth of the total number of tuberculosis cases in the world, are at risk due to a severe shortage of drugs and suitable medication, according to AFP.

Short supply of pediatric doses has forced clinics in India to turn away sick children while others are forced to split adult pills to approximate children’s dosages.

G. R. Khatri, the former head of India’s Central TB Division, called the pediatric shortages “disastrous”, reports Wall Street Journal.

Due to the shortages in anti-tuberculosis drugs such as Rifampicin and Streptomycin, patients have no choice but to stop taking medication. As a result, they develop drug-resistant tuberculosis, which is not treatable.

Doctors said overcrowding in congested houses has also contributed to the accelerating rate of transmission of the highly infectious disease, reports AFP.

More than 1.5 million people currently receive free drugs at 13,000 Indian government centers nationwide, as part of a partnership with the World Health Organization to beat TB. But the shortages could reverse decades of progress against the disease.

“The huge gains we’ve made in reducing TB are at risk,” said Bobby John, who heads New Delhi-based NGO Global Health Advocates.

Tuberculosis remains the biggest infectious-disease killer of adults in India. The disease killed 300,000 people in India in 2011 from 340,000 people in 1990.