HIV study warning

The number of new HIV infections in serodiscordant couples could quadruple over the next 10 years if people begin following advice from the Swiss Federal Commission for HIV/AIDS, says a researcher from the National Centre in HIV Epidemiology and Clinical Research.

The NCHECR’s Dr David Wilson has drawn into question the conclusions reached by the Swiss study in January of this year, which stated that people with HIV who were receiving effective anti-retroviral treatment could not transmit the virus to their negative partners through sexual intercourse.

Using mathematical modelling based on a population of 10,000 serodiscordant couples, Wilson predicted that there would be a dramatic rise in infections over the next 10 years. It was estimated that there would be 215 female to male transmissions, 425 male to female transmissions and 3524 male to male transmissions in each group of 10,000 couples.

While it is true that the individual risk of HIV transmission per act is fairly small for people on anti-retrovirals, the risk of transmission over large numbers of acts could be substantial, Dr Wilson said.

If the Swiss Commission’s conclus-ions were adopted at a community level and resulted in reduced condom use it would be likely to lead to substantial increases in infection.

President of the Australasian Society for HIV Medicine Dr Jonathan Anderson said it was still unknown whether anti-retrovirals caused a drop in viral loads in semen or vaginal and anal fluids.

Anti-retrovirals can complement consistent condom use but replacing condom use with medications may end in disaster, Dr Anderson said.

People who are diagnosed with HIV infection tend to reduce their number of new sexual partners, use condoms more consistently and disclose their status to their current partner or partners. We are concerned that there may not be the same behaviour if people believe themselves to be non-infectious.

This sentiment was echoed in a statement co-authored by AFAO, NAPWA, the Australian Society for HIV Medicine and the NCHECR which stated, there are no data to suggest that a population HIV prevention strategy based solely or predominantly on the use of antiretrovirals and associated with a reduction in condom use, will lead to fewer people becoming infected in the Australian and New Zealand populations, especially in the context of rising rates of sexually transmitted infections.