Abstract

OBJECTIVE: HIV Pre-exposure prophylaxis (PrEP) decreases risk of HIV acquisition however its efficacy is closely dependent on adherence. There is also concern that the preventive effect of PrEP may be offset by risk compensation, notably an increase in condomless anal sex.

DESIGN: Multi-site, open-label demonstration study that recruited people at current or recent risk of HIV infection in Melbourne, Australia.

METHODS: Participants were recruited from three general practice clinics and one sexual health clinic in Melbourne and consented to take daily tenofovir/emtricitabine for 30 months. Sexual practice data, HIV and sexually transmitted infection (STI) test results were collected at baseline and 3-monthly during follow up. PrEP adherence was evaluated by self-report at clinical visits, online surveys, refill-based assessments and dried blood spot (DBS) testing. We present a 12-month interim analysis.

RESULTS: 114 people were recruited. We observed a significant decline in condom use which occurred concomitantly with a significant increase in STIs over the first 12 months of PrEP. Incidence (per 100PY) of any STI was 43.2 and 119.8 at m0-3 and M3-12, respectively (IRR 2.77 (1.52, 5.56)). Adherence to PrEP medication was high by all measures, including six month TDF-FTC levels in DBS.

CONCLUSIONS: We found significant reduction in condom use and an increase STIs over the first 12 months of follow-up. High medication adherence rates coupled with a decline in condom use and a rise in STIs, suggests that prevention, early detection and treatment of STIs is a chief research priority in the current era of HIV PrEP.

Link to publisher’s web site