Researchers at the University of California, San Francisco, report in the January 2 edition of the journal AIDS that highly active antiretroviral therapy has reduced the ability of HIV-positive gay men to transmit the virus by 60%.
Analyzing data from a study of more than 530 young HIV-negative gay men conducted between 1994 and 1999, the researchers found the risks for the men of being infected by an HIV-positive partner fell by 60.4% since HAART became widely available. When taking into account that HAART also was allowing HIV-positive men in the city to live longer and potentially expose more people to the virus, the risk per sexual partner fell even further, to 67%. However, the reduced infectivity of the men didn't translate into lowered HIV-infection rates due to a doubling of unprotected anal sex reported by the young men in the study, which negated the gains made through widespread HAART treatment.
'The 60% decline in HIV infectivity we observed following the introduction of HAART suggests that the use of HAART in infected people not only confers clinical benefit but also is an attractive tool for HIV prevention' that will succeed only if accompanied by 'continued emphasis on avoidance of exposure,' the researchers conclude.
