Officials in Washington State report a local man has contracted HIV while taking PrEP. Not much has been revealed about the unnamed patient, including whether he took the medication consistently, but the Seattle & King County’s Public Health Department reports he was infected with a rare strain of HIV resistant to both medications in Truvada, the drug’s commercial name.
If taken correctly, PrEP can reduce the risk of HIV by 90% (though studies have reported numbers as low as 86% and as high as 99%). Of the hundreds of thousands of people taking PrEP worldwide, there have been only five reported cases of someone testing positive.
Last year, an Australian man participating in a PrEP clinical trial became infected with a drug-resistant strain of HIV.
A Dutch man on PrEP also tested positive in 2017, but doctors theorize his unusually high number of sex partners (50 a month on average), the frequency with which he had condomless sex, and the presence of other STIs in his system may have been unique factors.