Periodic presumptive treatment or doxycycline post-exposure prophylaxis for STI control among men who have sex with men in Indonesia (PRYSMA)

Funder
UK Medical Research Council (UKRI2160)

Duration
2025 – 2029.

Sites
Jakarta, Bali, & Bandung, Indonesia

Principal Investigator

Co-investigators

Prof. dr. Pande Putu Januraga (Universitas Udayana, Bali)
Evi Sukmaningrum, PhD (Universitas Katolik Atma Jaya, Jakarta)
Dr Keerti Gedela (Chelsea & Westminster Hospital, UK)
Assoc. Prof. Jennifer van Nuil (OUCRU Ho Chi Minh City)

PRYSMA is a clinical trial in Indonesia comparing two strategies to prevent sexually transmitted infections in men who have sex with men. One strategy uses doxycycline taken soon after sex, and the other uses periodic antibiotic treatment at clinic visits. The study will compare which strategy works best for preventing chlamydia, gonorrhoea, and syphilis, and will also monitor the risk of antibiotic resistance.

Background

Sexually transmitted infections such as chlamydia, gonorrhoea, and syphilis are common worldwide and are rising sharply in many countries, including Indonesia. These infections can cause serious health problems if untreated and also increase the risk of HIV. Men who have sex with men are especially affected, yet many infections go unnoticed because they cause no symptoms and routine testing is often unavailable.

Doctors and researchers are looking for practical ways to reduce these infections. One promising option is doxycycline, an antibiotic that can be taken soon after sex to lower the chance of catching an infection. Another option is a regular clinic visit every few months where antibiotics are given to prevent infection. Both strategies have shown good results elsewhere but have never been tested in Indonesia.

Methods

The PRYSMA study will invite men who have sex with men to join from friendly community clinics in Jakarta, Bandung, and Bali. Participants will be randomly assigned to one of three groups: standard care, doxycycline taken after sex, or periodic clinic treatment every three months. Everyone will receive free sexual health services, counselling, and testing for HIV and syphilis.

Researchers will collect information through interviews, surveys, and laboratory tests. They will also monitor for side effects, track how antibiotics are used, and study whether bacteria become resistant to the drugs. Community groups are directly involved in planning and guiding the study to ensure it meets the needs of those most affected.

Goals

The main goal is to see whether doxycycline after sex or regular clinic treatment is more effective than standard care at preventing chlamydia, gonorrhoea, and syphilis. The study will also find out which approach people find easier and more acceptable to use in daily life.

In the longer term, the results will guide health policy in Indonesia and similar countries. If successful, the findings could shape how clinics and communities work together to prevent sexually transmitted infections, while keeping a close watch on antibiotic resistance.