Prospective cohort study of HIV post-exposure prophylaxis for sexual assault survivors

There is a lack of standardized programs for HIV counselling and post-exposure prophylaxis (PEP) in the setting of sexual assault. We conducted an 18-month prospective cohort study assessing universal HIV counselling for all sexual assault survivors presenting to 18 Ontario Sexual Assault Treatment Centres. HIV PEP was universally offered to those at risk of HIV infection (high risk or unknown risk) presenting < or =72 h after the assault, using Combivir one pill and Kaletra three capsules twice a day for 28 days. Those who accepted HIV PEP were monitored via a schedule of frequent follow ups. The primary outcomes were acceptance and completion rates, and their predictors were determined using multivariable logistic regression. Adverse events (AE) were categorized using a standardized toxicity grading system. Of the 900 evaluable participants eligible for PEP, 798 (69 at high risk and 729 at unknown risk) were offered treatment. Acceptance rates were 66.7% (n=46) and 41.3% (n=301) for participants at high risk and unknown risk, respectively. Participants at high risk were 2.2 times more likely to accept PEP than those at unknown risk (adjusted odds ratio 2.2; 95% confidence interval 1.2-4.0; P=0.01). Overall, 23.9% high-risk (n=11) and 33.2% unknown-risk participants (n=100) completed PEP (P=0.20). Predictors of acceptance and completion included assault by a stranger and participant anxiety. AEs were common, with 77.1% of participants reporting grade 2-4 symptoms. A province-wide standardized program of universal HIV counselling and offering of PEP to sexual assault survivors with frequent follow up was successfully implemented and feasible.