XDR-TB poses a huge risk to HIV positive individuals, says Dr Karin Weyer, Director for TB Research at the Medical Research Council.
TB is the main killer of HIV positive people. So far, all HIV-positive individual co-infected with XDR-TB have died within a short period.
None of the combination antibiotic drugs traditionally used to treat TB or multi-drug resistant (MDR) TB are curing the patients.
Two new anti-TB drugs have been imported but it will take a number of months before their efficacy against XDR TB is established.
Weyer has also warned that the two new drugs will have to be tightly controlled as ‘we have reached the end of the line’ as far as treatment was concerned.
Doctors’ mis-prescribing of TB drugs was one of the major reasons for the XDR-TB outbreak, she said.
Many doctors had used second line TB drugs reserved for patients with MDR TB for ailments such as pneumonia without checking whether patients also had TB.
Other reasons for the development of drug resistance were the lack of supervision, monitoring and support of patients on TB treatment, according to World Health Organisation expert Mario Raviglione.
People with MDR TB are resistant to at least two drugs from among the first-line anti-TB drugs, while those with XDR also have resistance to three of the second-line anti-TB drugs.
Dr Lindiwe Mvusi, TB director in the national Department of Health, said health care professionals were being trained on the use of TB drugs and monitoring of patients.
However, experts and activists have expressed concern that South Africa’s response has not been urgent enough and that MDR-TB has for years developed unchecked in provinces with weak TB control programmes. The strain of XDR TB found in Tugela Ferry recently was first identified in the late 1980s.
But Mvusi defended her programme, saying: ‘The response has been to the best of our ability and urgent, taking into consideration that it takes a long time to confirm the diagnosis and the laboratory capacity to conduct these additional tests.’
It takes an average of three months to confirm drug resistant TB as cultures have to be grown in laboratories then exposed to different TB drugs to establish drug resistance.
South Africa’s TB cure rate has been a matter of grave concern for some time. The national cure rate stood at a dismal 50,8 percent in 2004.
The latest information from health districts countrywide reveal cure rates as low as 12 percent in the Nkangala district in Mpumalanga, 18% in KwaZulu-Natal’s Uthungula district and 20% in the Northern Cape’s Frances Baard district.
KwaZulu-Natal has the worst TB cure rate in the country (40%), followed closely by the Eastern Cape (41%).
The national health department currently has 303 confirmed XDR-TB cases, of which 263 are in KwaZulu-Natal and 10 in the Eastern Cape. So far the Western Cape has no confirmed cases.
South Africa has the fifth highest number of TB cases in the world. Cases have quadrupled from 61 486 in 1998 to 279 260 in 2004, mostly driven by the HIV epidemic.
Mvusi said additional staff needed to be recruited to deal with the increased patient numbers and that there was a shortage of hospital beds in which to isolate XDR TB patients, particularly in KwaZulu-Natal.
Patients suspected of having MDR and XDR TB are supposed to be treated in separate wards while laboratory tests are conducted. Once diagnosed, they are to be isolated in TB hospitals or designated wards with special infection control measures.
However, in a number of hospitals visited by Health-e coughing patients with undiagnosed TB were being treated in the general medical wards next to gravely ill HIV positive patients.
Patients with chronic coughs were wearing surgical masks while in some settings staff had also been supplied with special masks.
Weyer said the worrying aspect of XDR-TB was its rapid transmission to HIV positive individuals and the high mortality rate once they were infected.
‘Treatment is very limited or in some instances there are no options,’ she added.