STI rates in PrEP users very high, but evidence that PrEP increases them is inconclusive
A study of pre-exposure prophylaxis (PrEP) users presented at the Conference on Retroviruses and Opportunistic Infections (CROI 2017) last week in Seattle, showed that PrEP users had very high rates of sexually transmitted infection (STI) diagnosis – in the order of 20 times higher than among HIV-negative gay men in the general population.
There was also an increase in STI diagnoses from a time point a year before they sought PrEP to the date they started it. And the percentage of men reporting never using condoms for anal sex somewhat increased while they were on PrEP, though never exceeding 10% of all PrEP users.
The evidence that STIs increased further while people were on PrEP was, however, a lot more ambiguous.