Evidence presented to the conference showed that people who had never taken antiretroviral (ARV) medicine were increasingly being infected with HIV that was resistant to common ARVs.

They were probably infected by people who had either stopped taking ARVs or their ARV treatment had failed.

Countries where ARV programmes have been running for a long time were most likely to report drug-resistant HIV.

In parts of Brazil, for example, almost 20 percent of people tested had HIV that was resistant to at least one ARV.

In a study of almost 2 500 people in six African countries, drug resistance was highest in Uganda, which introduced ARVs earlier than the other countries surveyed, including South Africa and Nigeria.

At three Ugandan sites, almost 12 percent of people who had never been on ARVs before were infected with drug-resistant HIV.

Uganda was one of the first African countries to introduce ARVs, but in the mid-1990s some people were treated with one or two ARVs because of the exorbitant costs.

As the HI virus mutates easily, three different ARVs need to be taken at the same time every day for the patient’€™s entire life to prevent drug resistant HIV mutations.

In Uganda, there was most resistance to nevirapine and efavirenz, two of the most common ARVs used in Africa. Nevirapine has also been used for a number of years to prevent mothers from infecting their children with HIV.

PharmAccess, which conducted the African study, estimated that the risk of resistance increased by 38 percent for each year of ARV provision.

PharmAccess’€™s Dr Raph Hamers also reported on a study of young, newly infected Ugandans run last year which showed that over 8 percent had drug-resistant HIV.

A World Health Organisation (WHO) survey identified a number of factors that could drive the spread of drug-resistant HIV in Africa, including patients dropping out of ARV programmes, picking up their medication late and clinics running out of ARVs. ‘€“ Health-e News.