XDR-TB 'spreading fast'

2008-02-27 12:38

Maria Cheng

London - Drug-resistant tuberculosis is spreading faster than experts previously feared, according to a new report issued on Tuesday by the World Health Organisation.

Rates of drug-resistant TB in some countries topped 20%, the highest ever recorded.

"Ten years ago, it would have been unthinkable to see rates like this," said Dr Mario Raviglione, director of WHO's "Stop TB" department. "This demonstrates what happens when you keep making mistakes in TB treatment."

Though the report is the largest-ever survey of drug-resistant TB, based on information collected between 2002 and 2006, there are still major gaps: data were only available from about half of the world's countries.

In Africa, where experts are particularly worried about a lethal collision between the TB and Aids pandemics, only six countries provided information.

"We really don't know what the situation is in Africa," Raviglione said. "If multi-drug resistant TB has penetrated Africa and coincides with Aids, there's bound to be a disaster." Raviglione said it was likely that patients - and even entire outbreaks - were being missed.

XDR-TB in 45 countries

Experts are also worried about the spread of XDR-TB, or extensively drug-resistant TB, a deadly strain that is virtually untreatable in poor countries.

When an XDR-TB outbreak was identified in Aids patients in South Africa in 2006, it killed nearly every patient infected within weeks. According to the report, XDR-TB has now been found in 45 countries.

Globally, there are about 500 000 new cases of drug-resistant TB every year, about five percent of the nine million new TB cases.

The highest drug resistance rates were in eastern Europe. Nearly a quarter of all TB cases in Baku, Azerbaijan, were drug-resistant, followed by about 20% of cases in Moldova and 16% of cases in Donetsk, Ukraine.

High rates of drug-resistant TB were also found in China and India, which together comprise half of the world's problem.

Some officials said that these new data were probably an underestimate of the problem, with some governments simply failing to report.

Drug-resistant TB arises when primary TB treatment is poor. Countries with strong treatment programmes should theoretically have very little drug-resistant TB.

That is not the case in China, however, where the government reports a 94% TB completion rate.

"There's a huge, gross discrepancy there if they are then reporting 25% of the world's multi-drug resistant TB cases," said Mark Harrington, executive director of Treatment Action Group, a public health think tank.

"They are clearly nurturing a multi-drug resistant TB epidemic and failing to report XDR-TB at all."

With growing numbers of drug-resistant TB patients, there is concern health systems will soon be overwhelmed.

"We are totally off track right now," said Dr Tido von Schoen-Angerer, executive director of Medecins Sans Frontiere's Campaign for Access to Essential Medicines. Last year, only 30 000 multi-drug TB resistant patients were treated.

TB 'a threat to every person'

"The response so far has been completely insufficient, and we will continue to see rising figures until the world wakes up to this emergency," von Schoen-Angerer said.

To curb the outbreak, experts said that new diagnostic tests are needed to identify drug-resistant TB strains faster - current tests take about a month - as well as new drugs.

WHO said that a new diagnostic able to provide results within a day is now being tested in South Africa and Lesotho. If successful, the diagnostic could be introduced across Africa in a few months, though new labs will be needed to run the tests.

Experts hoped the WHO report would spur governments and donors to act. "Multi-drug resistant TB is a threat to every person on the planet," Harrington said. "It's not like HIV where you are only infected through specific actions," he said. "TB is a threat to every person who takes a train or a plane."

- AP