Pre-exposure prophylaxis (PrEP) discontinuations are common and are associated with subsequent HIV acquisition. The population-level impact of PrEP discontinuations is unknown.
Public health staff routinely asked men who have sex with men (MSM) with newly diagnosed HIV infection about their history of PrEP use as part of partner notification interviews in King County, Washington from 2013-2021. We assessed trends in the proportion of MSM who ever took PrEP and described reasons for PrEP discontinuation.
A total of 1,098 MSM were newly diagnosed with HIV during the study period, of whom 797 (73%) were interviewed, and 722 responded to questions about their history of PrEP use. Ninety-four (13%) reported ever taking PrEP. The proportion of MSM who ever used PrEP before HIV diagnosis increased from 2.3% in 2014 to 26.6% in 2020-2021 (P <0.001 for trend). The median time from PrEP discontinuation to HIV diagnosis was 152 days and median duration on PrEP was 214 days. Common reasons for stopping PrEP included self-assessment as being at low risk for HIV, side effects, and insurance issues. Nineteen men were on PrEP at the time of HIV diagnosis; mutations conferring emtricitabine/tenofovir resistance were identified for 8 (53%) of 15 men with available genotype data.
Over 25% of MSM with newly diagnosed HIV from 2020-2021 had ever used PrEP. Over 50% who discontinued PrEP were diagnosed <6 months after stopping. Strategies to preempt PrEP discontinuations, enhance retention, and facilitate resumption of PrEP are critical to decrease new HIV diagnoses.