A new Australian study published in The Lancet Infectious Disease Journal has shown that rates of Sexually Transmitted Infections (STIs) among users of Pre-exposure prophylaxis (PrEP), which prevents HIV, stabilised rather than increased following implementation of the oral medication.
Largest Study of Its Kind
The study, which is the largest of its kind globally, followed bacterial STI diagnoses in 70%, or 22,730, of Australian PrEP users between 2016 and 2019.
According to Michael Traeger, a PhD candidate at the Melbourne-based Burnet Institute and one of the authors of the study, the data suggest that “over four years of PrEP implementation in Australia, rates of STIs such as chlamydia and gonorrhoea have mostly stabilised among people who use PrEP.”
He went on to say that the data supports the conclusion that “PrEP implementation in Australia has not led to exponentially increasing STI rates, and that PrEP users are tested for STIs frequently.”
Initial Concerns Were STI Rates Might Spike
ACON’s HIV and Sexual Health Division Acting Director, Karl Johnson, welcomed the study’s findings. He said, “Today in NSW we have excellent biomedical technologies available which are contributing to a significant decrease in new HIV notifications.
“This includes PrEP, undetectable viral load, and comprehensive sexual health testing. This latest research only adds to the community benefit of these tools and bodes well for continued, robust engagement.”
Johnson noted that there were initial concerns globally that STI rates might spike following the introduction of PrEP. “Instead,” he said, “rates of STIs in PrEP users have remained mostly stable with some mild fluctuations across the four-year study lifetime.”
Slight Increase In Syphilis
However, the study registered a slight increase in the incidence of syphilis.
Traeger said part of the increase could be “driven by more condomless sex between gay and bisexual men living with HIV and PrEP users over time, as syphilis has historically been more common among men living with HIV in Australia.”