By Carina Elfving
A Canadian man who was adherent to his pre-exposure prophylaxis (PrEP) to prevent HIV recently tested positive for the disease (N Engl J Med 2017;376[5]:501-502).
This report suggested that contracting HIV-1 is possible despite adherence to PrEP if a person is exposed to a virus that is resistant to either one of the components of PrEP: emtricitabine (FTC; Emtriva, Gilead) or tenofovir disoproxil fumarate (TDF; Viread, Gilead), or both.