As you may already know, PrEP is a way for people who don’t have HIV but who are at very high risk of getting it to prevent HIV infection by taking a pill every day.
The man was on Truvada, a highly effective PrEP (containing tenofovir and emtricitabine) which was known to lower the chances of getting HIV by 92 percent.
In his presentation, Dr. David Knox noted the patient was a 43-year-old gay man, a regular at the Maple Leaf clinic who regularly got tested for HIV. In April 2013, following a suggestion he start PrEP, the man began the regimen. According to Knox, the patient's HIV-positive partner was on antiretroviral therapy with "undetectable" levels. Yet the man also reported “multiple acts of anal receptive sex with casual partners without the use of condoms” occurring within two to six weeks of testing positive for HIV.
The patient insisted he was adherent to his medication and both pharmacy records and dried blood spot analysis indicated “consistent dose-taking in the preceding one to two months, said Knox.
“Failure of PrEP in this case was likely due to the transmission of a PrEP-resistant, multi-class resistant strain of HIV 1,” said Knox.
No doubt, this case will spark more questions and concerns about the efficacy of Truvada.