STI rise not linked with condom use among men using PrEP

PrEP is a highly effective medication that can reduce HIV transmission by up to 99 per cent in people at risk of infection. While the drug is widely regarded as a ‘game changer’ in the fight against HIV, public health experts have questioned whether PrEP use may also lead to an increase in STIs if people reduce their condom use.

Findings published today in the Journal of the American Medical Association (JAMA) analysed data of more than 3000 participants in the Victorian PrEPX Study.  It found that while condom use was not a significant predictor of acquiring an STI when using PrEP, STI risk has increased in the study group – and is associated with having more casual partners and group sex.

Alfred infectious diseases physician and PrEPX Study Principal Investigator, A/Prof Edwina Wright said the findings are important because they highlight where to target education.

“We need to address these findings by engaging in more research to prevent STIs, including vaccines and antibiotics that may prevent STIs,” A/Prof Wright said.

JAMA study lead author, Burnet PhD student Michael Traeger, said the study findings suggest that STI prevention campaigns should not focus solely on condom use, but also on reducing the time to STI diagnosis and treatment through frequent testing.

“It’s important to understand that when people start taking PrEP, they also get tested more frequently, so STIs are more likely to be detected,” Mr Traeger said. “As PrEP uptake increases, identifying individuals most at risk of STIs will become increasingly important.”

Burnet Head of Public Health Professor Mark Stoové said “This study will be part of the evidence that I think will inevitably change guidelines in other jurisdictions to facilitate more frequent, quarterly testing.”

Thorne Harbour Health CEO Mr Simon Ruth said this study highlights that PrEP is more than a pill for HIV prevention.

“It’s a highly effective sexual health strategy that includes quarterly STI testing that interrupts the onward transmission of other STIs.

“We now have an opportunity to further assist gay men in looking after their sexual health by exploring more targeted strategies for those at higher risk of STIs,” Mr Ruth said.

The research published in JAMA used data from almost 3000 participants in the PrEPX Study, which was led by The Alfred hospital, with support from the Victorian Government, and Thorne Harbour Health (formerly the Victorian AIDS Council). Results were collated through the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of STIs and BBVs (ACCESS).