Kirby Institute researchers have found that gay and bisexual men who use crystal methamphetamine during sex (a practice known as chemsex) are more likely to include biomedical HIV prevention strategies when engaging in condomless sex than those who do not use crystal methamphetamine.

Chemsex has traditionally been linked with ‘risky’ sexual behaviours, and for a long time, gay men engaging in chemsex have been thought to be the group most at risk of HIV and other infectious diseases. But this research indicates that this group have embraced recent innovations in HIV prevention, and for the most part, are now engaging in sexual activity without the risk of HIV transmission.

“HIV prevention has been revolutionised in recent years by Treatment as Prevention and PrEP,” says Mohamed Hammoud, who is the lead author of the paper.

Treatment as Prevention (TasP), means that people living with HIV who are on effective antiretroviral treatment are unable to transmit HIV to their partners, due to having an undetectable viral load. PrEP is a daily medication that prevents HIV negative people from contracting the virus.

Among men who had sex without condoms, methamphetamine users were one third more likely to use PrEP or TasP than were other men. “Our research finds that gay men who use crystal methamphetamine to engage in chemsex appear to be better at using PrEP and TasP to prevent HIV risk than are other gay men,” says Mr Hammoud.

The paper analysed responses from the Flux study, which surveyed more than 1,300 gay and bisexual men in 2018; the largest study globally of drug use among this population. The results suggest that crystal methamphetamine use may no longer be a reliable indicator of those at highest risk of HIV and although HIV prevention efforts among these men need to be maintained, similar efforts among other groups of gay and bisexual men may therefore need to be prioritised.

“PrEP and undetectable viral load can protect men from acquiring HIV even when they engage in behaviours that have previously been thought of as high risk. So, it may well be that these men that were previously the highest risk group are now relatively low risk, as long as they maintain their use of these HIV prevention strategies,” says Associate Professor Garrett Prestage, who is the paper’s senior author.