Tuberculosis (TB) is the world's deadliest infectious disease after HIV/AIDS but the fight against the disease is being dealt a double blow.
"[By using substandard drugs to treat TB], in addition to the fact that the patient remains infectious and his treatment results will be really, really poor, you also develop a multi-drug resistant TB which is one of the worst forms of TB that unfortunately we have in this world. And that's much more difficult to treat, it's much more difficult to cure and is much more expensive."
- Dr Luchica Ditiu, the executive secretary of the Stop TB partnership
A new study says developing countries are awash with fake and substandard drugs. And that is making the disease more resistant - and in some cases, virtually impossible to treat.
Virulent new forms of TB are threatening to wipe out a decade of gains made in the treatment of the disease.
Substandard and counterfeit antibiotics are contributing to dangerous new strains that are resistant to some or all of the drugs on the market.
Investigators in the US are reporting alarming findings from the biggest-ever study of its kind.
During this study, researchers collected samples of two frontline antibiotics used to treat TB from pharmacies and local markets in 17 countries.
They found that nearly one in 10 failed to meet basic quality standards and around half of those that failed had no active ingredients at all.
It also showed that most of these substandard drugs came from legitimate manufacturers, but had been poorly made or had corroded in transport. Others appeared genuine, but turned out to be fake.
And it is this misuse, mishandling and mistreatment that is conspiring to make TB more resistant.
"The problem of multi-drug resistant TB is a major issue for TB control overall but also [it] is a general health system problem, it's that [and] also the mixture of different issues relating to the health systems not being adaptable to the patients' needs .... The treatment is quite long ... and many patients stop treatment as soon as they feel good or they go for over-the counter treatments."
- Masoud Dara, from the World Health Organization
Tuberculosis usually affects the lungs and is spread from person to person by coughing and sneezing. Around nine million people fall ill from TB every year - of those, more than 400,000 people have a form of the disease considered multidrug-resistant.
In 2011, 1.4 million people died from TB, although that figure has been falling since 2006.
There has also been another setback in the fight against TB. Scientists had high hopes for a promising new vaccine - the first in almost a century. Trials went well with adults, but had little impact on babies.
Researchers in South Africa selected 2,794 healthy babies, who had been given the standard BCG vaccine. The new vaccine was then given to around half of them while a harmless control drug was given to the others as part of a three year trial.
A total of 39 cases of TB were found in the control group, and 32 in the group with the new vaccine. This showed that there was no significant distinction, and the drug was not the breakthrough that was hoped for.
So, how much of a rise has there been in multi-drug resistant forms of TB? And what impact does it have on fighting the disease?
Inside Story, with presenter Laura Kyle, discusses this with guests: Paul Jensen, the co-author of the study Substandard and Falsified Anti-Tuberculosis Drugs and the president of Pivit Consultancy, which specialises in medical strategy; Masoud Dara, the team leader of the World Health Organization Europe's Tuberculosis programme, and a former manager at Doctors Without Borders; and Dr Luchica Ditiu, the executive secretary of the Stop TB partnership, a physician and researcher.