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Updated: Feb 26, 2026

An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings
Published on: March 30, 2014
Medication adherence, condom use and sexually transmitted infections in Australian preexposure prophylaxis users
Luxi Lal1, Jennifer Audsley, Dean A Murphy
1aThe Burnet Institute bDepartment of Infectious Diseases, The Alfred Hospital cDepartment of Infectious Diseases, Monash University dThe Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria eDepartment of Gender and Cultural Studies, University of Sydney fCentre for Social Research in Health, University of New South Wales, New South Wales gMelbourne Sexual Health Centre hCentral Clinical School, Monash University iSchool of Population Health and Preventive Medicine, Monash University jPrahran Market Clinic kNorthside Clinic lThe Centre Clinic, Victoria, Australia mUniversity of Colorado Anschutz Medical Campus, Colorado, USA nVictorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Victoria, Australia oGladstone Institutes pUniversity of California-San Francisco qSan Francisco AIDS Foundation, San Francisco, California, USA. *Luxi Lal and Jennifer Audsley equal first authors. †John De Wit and Edwina Wright equal final authors.
Objective:
HIV preexposure 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:
Multisite, 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 (TFV/FTC) 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 testing. We present a 12-month interim analysis.
Results:
A total of 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 100 person-years) of any STI was 43.2 and 119.8 at months 0-3 and 3-12, respectively [incidence rate ratio 2.77 (1.52, 5.56)]. Adherence to PrEP medication was high by all measures, including 6 month TFV/FTC levels in dried blood spot.
Conclusion:
We found a significant reduction in condom use and an increase in STIs over the first 12 months of follow-up. High medication adherence rates occurring with a decline in condom use and a rise in STIs, suggest that prevention, early detection and treatment of STIs is a chief research priority in the current era of HIV PrEP.
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