Fears Over Drug-resistant Tb in Aids Patients

A form of tuberculosis that does not respond to known drugs has emerged in a rural district of South Africa and is killing people being treated for Aids, scientists have say.

The revelation shocked delegates yesterday at the International Aids Conference in Toronto, where the findings were announced. Multi-drug resistant tuberculosis, or MDR TB, is mainly found in eastern Europe, but there has been an epidemic in New York and cases in the UK. It can be treated but the drugs are expensive and recovery takes a long time.

It was thought there was little MDR TB in Africa but researchers from Emory University school of medicine in Atlanta found 41% of TB patients in a district of KwaZulu-Natal had it. Potentially more alarming was that 10% of them had extensively drug-resistant TB (XDR TB), which does not respond to any drugs.

The Atlanta team surveyed the population of one rural district, where HIV infection is rife and Aids drugs have been made available, to establish whether there was drug-resistant TB, and if so, what proportion of TB cases were involved. They tested 1,540 patients and found that a third (536) had TB. Of those, 41% (221) had MDR TB.

A further 10% - 53 patients - had XDR TB. Doctors found that first-line and second-line TB drugs had no effect on the disease, and 52 patients quickly died.

The tests showed that all but one of the XDR TB patients had a genetically similar strain. It is thought the disease spread to the community from two infected healthcare workers.

The scientists told the conference their surveillance exercise had uncovered "a markedly greater MDR TB prevalence than previously recognised".

All those with XDR TB whose HIV status was known were HIV positive. TB is a major risk for people with HIV because the virus depletes the immune system, making it hard to fight off infections.

The researchers underlined the worrying nature of their findings in Africa for people with HIV who are being given a chance to lead healthy lives on antiretroviral (ARV) drugs. "The convergence of the TB/HIV epidemic with MDR and XDR TB in resource-poor settings is a deadly threat to gains in survival achieved by TB Dots [the TB drug treatment programme] and ARV therapy," they said.