Limited awareness of the effective timing of HIV post-exposure prophylaxis among people with high-risk exposure to HIV

The effectiveness of post-exposure prophylaxis (PEP), a major strategy in the battle against HIV, depends on awareness of this modality and its proper timing among high-risk groups. While general awareness of PEP is improving, recently estimated to be 36-47% among men who have sex with men (MSM), PEP implementation remains disappointingly low and may be driven by limited awareness of effective PEP timing window. The level of detailed understanding of PEP timing and effectiveness among populations at risk has not been prospectively assessed to date. We prospectively evaluated, for the first time, actionable awareness regarding effective timing of PEP among a large cohort of individuals tested for HIV following unprotected sexual intercourse. Four hundred participants were assessed between December 2014 and February2016. Overall awareness of the option of PEP was 60% and was significantly higher among male members of the LGBTQ community (755% as compared to 526% among heterosexual males) and those undergoing past HIV testing (671%). However, only 24% of individuals at risk were aware as to the proper timing of effective PEP treatment, thereby leading, in the majority of cases, to missing the window of opportunity for PEP treatment. This study highlights the lack of knowledge as to the specific requirements needed for effective PEP timing. Expanded advertising, better targeting of the heterosexual population, training of family physicians in the field of gender, sexuality, and LGBTQ medicine, may improve effective PEP availability, thereby reducing HIV transmission.