Alarm bells on HIV-drug resistance - Study raises fears as patients develop immunity to antiretroviral therapy

JOHANNESBURG - The prevalance of HIV-positive people who have developed a resistance to life-prolonging antiretroviral treatment (ART) is a cause for concern for South Africa, scientists warn.

While scientists have known about HIV-drug resistance since 2002, a new study raises fears that the new form of the virus could spread rapidly if not controlled.

A study researching resistance to treatment and published in the latest Lancet Infectious Diseases Journal followed 2 590 participants in six African countries South Africa, Kenya, Uganda, Ghana, Zambia and Zimbabwe.

Findings showed that of the 2 436 participants who remained part of the study until the end, 139 were resistant to antiretrovirals (ARVs) such as nevirapine, tenofovir, zidovudine, efavirenz and lamivudine.

A total of 176 South Africans participated in the research, which showed that two of them had developed resistance to ART. Both had never taken ARVs before.

While drug resistance has been reported recently in people who had begun ART, the new study has sparked fears among scientists that the country could be heading for another severe drug-resistance outbreak similar to the one experienced in 2005.

Six years ago, 52 people died within three weeks after KwaZulu-Natal was hit by an extensive drug-resistant tuberculosis (XDR-TB) outbreak.

Like the HIV drug resistance currently detected, XDR-TB started with one case in 2001 and exploded in 2005, leaving more than 230 people dead a year later.

Dr Dave Spencer, head of the adult antiretroviral programme at the non-profit organisation Right to Care, admitted this week that if primary HIV drug resistance (resistance in people who have never used ARVs) was not controlled, it could become problematic.

'The number of people with primary HIV drug resistance at our clinic at Helen Joseph Hospital is still relatively low, but we are concerned that the numbers will increase in time. Data from Gauteng suggests that the rate of primary resistance is around 5%,' he said.

Right to Care provides clinical care and treatment to people living with HIV. It is estimated that 800 000 people between the ages of 15 and 49 are HIV positive in Gauteng. Of those, 40 000 are likely to have developed drug resistance.

Health Minister Aaron Motsoaledi said government had set up a surveillance centre to monitor HIV drug resistance.

'We can't take our eyes off the ball because if we do, we may find ourselves in a similar situation as with the drug-resistant TB. We need to keep track of what is happening and ensure that people do not default on treatment,' he said.

While there are no official statistics for the population of people infected with HIV in South Africa, experts believe that the resistance rate in people who have never used ARVs is very low.

The scientists' estimations do not stray far from the findings of the study, which found that the overall prevalence of primary resistance in the participating countries was 5.6%. It also revealed that South Africa had the lowest resistance rate (at 1.1%), while Uganda had the highest (at 12.3%).

Researchers attributed the high rate in the East African country to the fact that ART was started earlier there than in the other five countries.

It also highlighted that countries scaling up their ART programmes, like South Africa, were at a greater risk of increased resistance as more people defaulted on treatment, developed resistance and then transmitted HIV-drug resistance to their partners.

Dr Francesca Conradie from the Clinical HIV Research Unit at the University of Witwaters-rand and co-author of the study, said primary HIV-drug resistance was not at the stage where it could be considered an 'emergency' in South Africa. However, she warned that the longer the ARV programme continued, the more drug resistance would develop.

'What we should focus on right now is ensuring that resistance is kept to a minimum by encouraging all those on ARVs to take their medication regularly, continue using condoms and strengthening surveillance systems for detecting transmitted resistance,' she said.

The latest data on HIV-drug resistance are expected to be released on Tuesday when scientists and medical experts meet for the sixth South African HIV and TB Drug Resistance and Treatment Monitoring Workshop in Botswana.

News date: 2011-11-06


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