Multidrug-Resistant HIV-1 Infection despite Preexposure Prophylaxis

Abstract
Preexposure prophylaxis with emtricitabine (FTC)–tenofovir disoproxil fumarate (TDF) has been shown to be efficacious in preventing human immunodeficiency virus type 1 (HIV-1) infection in men who have sex with men and in whom adherence to treatment is high, as measured by levels of tenofovir diphosphate (TFV-DP) in dried blood spots.1 We describe a case of HIV-1 infection despite FTC-TDF–based preexposure prophylaxis.2