High prevalence of STIs among men engaged in transactional sex and alcohol use in western Kenya: important implications for STI prevention interventions.

Objectives: Better data on aetiological prevalence of sexually transmitted infections (STIs) among African men could greatly strengthen STI prevention efforts and convey benefits to women as well. In an ongoing study among men in Kenya, we analysed baseline STI prevalence and individual characteristics associated with STI.

Methods: In Siaya County, Kenya, we recruited men aged 18-39 years who self-reported engagement in transactional sex and alcohol use. We administered a baseline questionnaire to participants and conducted testing for HIV, herpes simplex virus type 2 (HSV-2), Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection. Characteristics associated with bacterial STIs were analysed using logistic regression and we estimated the positive and negative predictive values (PPV/NPV) of syndromic management of these infections.

Results: We enrolled 1500 participants from July 2022 to March 2023. Participant mean age was 27.9 years, 62.2% were married/cohabitating and 53.5% were heavy alcohol users (Alcohol Use Disorders Identification Test-Consumption≥4). Participants reported a mean of 4.2 sexual partners and 3.5 transactional sex partners in the past 3 months. HIV prevalence was 9.5%, HSV-2 was 38.7%, CT was 14.3% and NG was 2.5%. Combined CT and/or NG infection was detected in 16.1% of participants.Compared with participants uninfected, those testing positive for CT and/or NG were younger (p=0.001), had more sexual partners (p=0.027) and transactional sex partners (p=0.039), were less likely to have used a condom at last sex (p=0.015) and were more likely to self-report having an STI besides HIV in the past 12 months (p=0.002). The PPV and NPV for currently experiencing CT and/or NG symptoms were 33.3% and 84.4%, respectively.

Conclusions: Among Kenyan men engaged in transactional sex and alcohol use, STI prevalence was high. These data fill an important gap about STI prevalence and risk factors in African men highlighting the risk of ongoing transmission and the need for targeted prevention programmes and expanded access to testing and treatment.