The proportion of HIV-positive gay and bisexual men having ‘unsafe sex’ falls from 42% to 2% when a nuanced definition of the term is used, Dr Keith Horvath of the University of Minnesota and colleagues report in the Archives of Sexual Behaviour.
“Traditional definitions of sexual risk (condomless anal sex or condomless anal sex with a serodiscordant partner) may not suffice, given the success of biomedical prevention in the absence of condoms,” they say.
Their data come from a cohort of HIV-positive gay and bisexual men living in New York who were recruited to an online intervention to improve adherence to HIV treatment. Of the 401 participants, 281 reported anal sex in the past three months and this group are the focus of this analysis.
The participants’ average age was 38 and they had been diagnosed for an average of 12 years. Over half were black and a third were college-educated. Men had an average of nine sexual partners in the past three months and half reported stimulant drug use.
The traditional definition of ‘risky sex’ is condomless anal sex with a partner who is HIV negative or of unknown HIV status – 42% reported this in the past three months.
Given that undetectable = untransmittable (U=U), a more nuanced definition takes into account viral load. The researchers’ second definition was men with an unsuppressed viral load (over 200) who reported condomless anal sex with a partner who is HIV negative or of unknown HIV status – 6% reported this.
Partners may also be protected by the prevention medication PrEP. The researchers’ third definition was men reported condomless anal sex with a partner who is HIV negative or of unknown HIV status, who was not on PrEP – 25% reported this.
The most accurate definition would take into account both viral load and PrEP. The final definition of unsafe sex was therefore men with an unsuppressed viral load who reported condomless anal sex with a partner who is HIV negative or of unknown HIV status, who was not on PrEP – 2% reported this.
Horvath K et al. Defining Sexual Risk in the Era of Biomedical HIV Prevention: Implications for HIV Research and Practice. Archives of Sexual Behaviour, online ahead of print, 2019.