Simple measures could prevent spread of drug-resistant TB, study shows

An epidemic of deadly drug-resistant tuberculosis has spread from South African hospitals, but a mix of simple preventative measures could cut the number of future cases in half, according to a study released Friday.

Extensively drug-resistant (XDR) tuberculosis has emerged over the last decade as a major health concern around the world, especially in poorer nations.

While accounting for only a tiny fraction of the nine million new cases of TB reported each year, XDR tuberculosis is on the rise, according to the World Health Organisation (WHO).

The drug-resistant strain is also virtually untreatable, killing well over 90 percent of those infected.

In the absence of a cure, a team of US and South African researchers led by Yale epidemiologist Sanjay Basu has proposed a cost-effective strategy to keep the disease in check.

Their study, intended as a health policy model for developing countries, focuses on the South African town of Tugela Ferry, which reported the earliest, and one of the largest, clusters of XDR tuberculosis in the country.

The disease claimed all but one of the town`s first 53 victims, most of whom died within two weeks of being diagnosed.

All suffered from HIV, and more than two thirds had been in hospital shortly before falling ill, "suggesting that nosocomial" -- hospital-based -- "transmission of XDR tuberculosis might be a driver of this epidemic."

Tuberculosis can be particularly lethal for those with HIV and AIDS, and has reached epidemic levels in developing countries with high HIV infection rates, such as South Africa.

Basu and his colleagues used a mathematical model to calculate that, under current conditions, 1,300 new cases will emerge in the town by 2012.

Wearing masks, shifting to out patient care, improving ventilation and testing for drug resistance would prevent a third of those, they concluded.

Adding HIV treatment and isolation wards for TB patients "could avert nearly half of XDR tuberculosis cases in Tugela Ferry over the next five years," they reported.

But the forced detention of patients with XDR tuberculosis, advocated by some health officials, would only discourage those infected from seeking treatment and aggravate any epidemic, the study says.

In a comment, also published in The Lancet, epidemiologists Travis Porco and Wayne Getz of the University of California endorse the proposal, but caution that the preventative measures outlined are not enough.

They also say that stopping the spread of tuberculosis -- which has been readily curable for more than half a century -- is more than a local problem.

"Multidrug and extensive drug resistance are monsters of our own creation," they write.

"The control of XDR tuberculosis in Africa are national and international responsibilities, and the world community ignores this message at great peril."

Tuberculosis killed 1.6 million people in 2005, according to the WHO. Thirty-seven countries from all regions of the world have reported XDR TB cases as of May 2007.

sections: Nature & Health