When Indian street-food seller Kumar Pal first began treatment for multidrug resistant tuberculosis two years ago, he quickly spiralled into depression and gave up hope of living.

Weighing just 35 kg, shunned by his relatives and friends and in extreme pain due to the side effects of a cocktail of medicines, 40-year-old Pal spent weeks in bed.

"I stopped taking the medicines. I was certain that I was going to die anyway. I worried about how my wife would manage with four children," said Pal, sitting in his two-roomed home in the maze of lanes in Sunder Nagari slum in northeast Delhi.