How drug resistant TB threatens to spread across the globe

ITV News has travelled across the world to report on the growing global threat of the spread of deadly drug-resistant 'super bugs'.

In the second of our three-part series, we investigate the battle to contain and overcome resistant TB in South East Asia.

The class of children at a school in an isolated rural Thai community are coming to terms with an unusual new reality.

While they learn each day, their parents are actually patients.

They are being treated here for not only TB (tuberculosis) but multi drug resistant TB, their disease having developed to make many strong drugs ineffective.

The disease's bacterial infection mainly affects the lungs, though it can impact on any part of the body, including the tummy glands, bones and nervous system.

And it's transmittable, spreading through inhaling tiny droplets from the coughs or sneezes of an infected person.

Without isolation these parents could easily pass it onto family, friends and then far beyond.

It means the people coming to this tiny TB clinic are a very real threat to the world's ambition to eradicate TB by 2035.

With the drug resistance strain infecting almost half a million people and growing, the global ambition looks more and more likely to fail.

The danger comes less from the patients in isolation here, but from those yet to be diagnosed.

Dr Michele Vincenti-Delmas, director of TB at the Shoklo Malarial Research Unit, told ITV News the threat in the outside world is very real.

"If (people) aren't diagnosed and transmitting, if they don't get the treatment early, it's not good, it can spread," she said.

The challenge at the clinic is to tackle the fifth of patients who have built up resistance to the drugs that can help them.

The patients come emaciated and weak.

There are 19 under treatment for whom the regular TB drugs did not work.

One told ITV News he panicked when he found the drugs were not working.

"I wasn't scared at first because I thought it was normal TB," he said. "When I found out it was drug resistant TB I became scared and very anxious."

Dr Vincenti-Delmas said bad treatments or contamination are to blame for developing the dangerous immunity.

"(They've) been treated before, but not completely, stopped, started again, (been given) not good drugs," she said.

"(Then) there is a mutation from himself, from his bacteria or he gets contaminated by someone who already has it."

Those with resistance are put onto so-called "second line", stronger drugs.

But these carry severe side effects.

One elderly patient has gone deaf because of the treatment.

"I just want to get better. I want to be cured," he told ITV News.

The second line treatment takes two years, and even then there is no guarantee patients will respond.

Thailand is battling one of the highest rates of TB.

But the growing spread of the disease is a global concern.