Related Experiment Video
Updated: Feb 4, 2026

Key Elements of Photo Attraction Bioassay for Insect Studies or Monitoring Programs
Published on: July 26, 2018
Princess PrEP program: the first key population-led model to deliver pre-exposure prophylaxis to key populations by
Nittaya Phanuphak1, Thanthip Sungsing1, Jureeporn Jantarapakde1
1PREVENTION, Thai Red Cross AIDS Research Centre, 104 Rajdumri Road, Pathumwan, Bangkok 10330, Thailand.
Abstract:
Background No data are available on the feasibility of pre-exposure prophylaxis (PrEP) delivered by trained key population (KP) community health workers. Herein we report data from the KP-led Princess PrEP program serving men who have sex with men (MSM) and transgender women (TGW) in Thailand.
Methods:
From January 2016 to December 2017, trained MSM and TGW community health workers delivered same-day PrEP service in community health centres, allowing clients to receive one PrEP bottle to start on the day of HIV-negative testing. Visits were scheduled at Months 1 and 3, and every 3 months thereafter. Uptake, retention and adherence to PrEP services and changes in risk behaviours over time are reported.
Results:
Of 1467 MSM and 230 TGW who started PrEP, 44.1% had had condomless sex in the past 3 months. At Months 1, 3, 6, 9 and 12, retention was 74.2%, 64.0%, 56.2%, 46.7% and 43.9% respectively (lower in TGW than MSM at all visits; P<0.001), with adherence to at least four PrEP pills per week self-reported by 97.4%, 96.8%, 96.5%, 97.5% and 99.5% of respondents respectively (no difference between MSM and TGW). Logistic regression analysis identified age >25 years, being MSM and having at least a Bachelors degree significantly increased retention. Condomless sex did not change over the 12-month period (from 47.2% to 45.2%; P=0.20). New syphilis was diagnosed in 4.9% and 3.0% of PrEP clients at Months 6 and 12 (cf. 7.0% at baseline; P=0.007). Among PrEP adherers and non-adherers, there were one and six HIV cases of seroconversion respectively, which resulted in corresponding HIV incidence rates (95% confidence interval) of 0.27 (0.04-1.90) and 1.36 (0.61-3.02) per 100 person-years.
Conclusion:
Our KP-led PrEP program successfully delivered PrEP to MSM and TGW. Innovative retention supports are needed, especially for TGW and those who are young or with lower education levels. To scale-up and sustain KP-led PrEP programs, strong endorsement from international and national guidelines is necessary.
Related Concept Videos
Conservation of Small Populations
Key Techniques in Microbiology
Key Elements for Plant Nutrition
What is Population Genetics?
Population Growth
What are Populations and Communities?

