Concerns have been raised over claims made by Swiss HIV experts that HIV-positive individuals who are on antiretroviral treatment and who have no sexually transmitted infections (STI’s) carry ‘no relevant risk of transmission’.
The statement, which appeared in the Bulletin of Swiss Medicine, was released on behalf of the Swiss Federal Commission for HIV/AIDS (SFCHA) by four of Switzerland’s leading HIV experts and reflects results from a review of studies pertaining to the rates of transmissions among sero-discordant couples.
The SFCHA announced  that, according to their findings, ‘an HIV-infected person on anti-retoviral therapy with completely suppressed viremia (‘effective ART’) is not sexually infectious, i.e. cannot propagate HIV through sexual contact.’
They acknowledged that while a transmission of HIV could not be completely ruled out, the possibility of it occurring while the HIV-positive partner was on ARV treatment was ‘negligibly small’ as long as in the last six months the viral load had remained undetectable and neither partner had had any STIs.
UNAIDS and WHO have taken the position that an undetectable viral load had not yet been proven to completely eliminate the risk of transmitting HIV,  a position with which Don Baxter, Executive Director of the Australian Federation of AIDS Organisations (AFAO) concurs.
‘While research suggests an undetectable viral load reduces the risk of HIV transmission… (t)he use of viral load in prevention is not a substitute for safe sex,’ Baxter said.
‘It’s also important to realise that the claims made by the Swiss Federal AIDS Commission were highly conditional; they require six months of undetectable viral load, strict adherence to HIV medication and being free of any sexually transmitted infections. So the reduction in transmission risk isn’t something that applies to all people with HIV on treatment.’
Furthermore, the studies examined by the Swiss research team were all based on heterosexual couples. Given that there is higher risk of transmission of HIV through anal as opposed to vaginal sex, it is unclear how relevant the results are to MSM.
Baxter added that, ‘For gay men with more than one sexual partner it would be very difficult to be sure you are always STI-free. For sexually-active gay men in HIV sero-discordant couples – one poz, one neg – using undetectable viral load as a substitute for routine condom use would be a very risky approach.’
Baxter went on to add that, if anything, the study should reinforce the importance of regular testing and early treatment for STIs.
