"Normal TB is really easy to treat, four drugs over six months at a cost of $5 will almost always cure you," says Dr Udwadia.
But, he adds, if patients are given the wrong drugs or incorrect doses, or are irregular with their medication, the TB bacteria becomes resistant to the drugs.
This drug-resistant TB takes far longer - up to two years - and thousands of dollars to treat. It requires many more drugs - 250 injections and 15,000 pills, to be precise.