A laboratory worker sorts tuberculosis test samples at a clinic for transmittable diseases funded by Medecins Sans Frontieres.

Johannesburg - Researchers have identified a new strain of tuberculosis in 17 patients in the Eastern Cape that is totally resistant to all current drug regimes.

When an earlier study of extreme drug-resistant (XDR) TB in the Eastern Cape showed that patients weren’t responding to treatment, epidemiologists at Stellenbosch University decided to investigate.

The Eastern Cape cases are the first to be identified in South Africa, which is the fourth country to report totally drug-resistant (TDR) TB. It was discovered in India last year, in Italy in 2003 and in Iran in 2009.

What they found was an emerging strain of TB that has shown resistance to at least 10 anti-TB drugs currently in use in the health sector.

According to Professor Tommy Victor, from Stellenbosch University’s Division of Molecular Biology and Human Genetics, the World Health Organisation and many experts think the name “totally drug-resistant”, which is currently used in scientific literature, is not appropriate.

They believe there may be a cure for TDR among some of the new drugs being developed, or medication not in use any more.

“We really are facing bacteria that has become increasingly resistant, and there are now some bacteria that are hyper-resistant, irrespective of the definition,” said Victor, who co-authored the study.

In the scientific paper, published in the Emerging Infectious Disease Journal this month, they used molecular techniques to study cultures of the tuberculosis bacterium of just under 400 multi-drug resistant (MDR) TB patients in the Eastern Cape. Among these, a large number were pre-XDR and XDR, and 17 cases of TDR emerged.

There are about 18 000 new MDR cases diagnosed each year, and there might be more TDR cases in South Africa, said Victor, explaining that 17 cases had emerged from only 400 MDR samples tested.

A shortcoming of the study, acknowledged by the authors, is that they studied only the cultures from the infected patients, and don’t have any data on patient outcomes.

Although a related study on the Eastern Cape group showed that patients responded quite badly to even the fiercest treatment.

– Health-e News