Predictors and frequency of STIs among MSM on PrEP in Kiambu County, Kenya

Document Type



Population Health (East Africa)


Men who have sex with men (MSM) face a high burden of sexually transmitted infections, hence form a vital target population for public health response. The primary objective of this study was to determine the frequency and predictors of selected sexually transmitted infections among men who have sex with using pre-exposure prophylaxis (PrEP) in Kiambu County.
An analytical cross-sectional study design was and MSM currently using PrEP were enrolled. Venue-based sampling was adopted and a sample size of 157 respondents was included in the survey. A total of 4 key informant interviews were conducted and 3 focus group discussions comprising 11, 8 and 7 members respectively provided additional information regarding PrEP use and sexually transmitted infections (STI). Data was analyzed using Stata version 17.
STI prevalence was 37.5%, with the highest rates observed for co-morbidities of chlamydia and gonorrhoea at 47.9%, and genital warts at 31.3%. Other prevalent STIs included chlamydia (10.4%), chlamydia with genital warts (4.2%), syphilis (4.2%), and gonorrhea (2.1%).. Missing to take PrEP was not significantly associated with STI prevalence [p=0.093]. However, the regression analysis indicated significant associations between STI prevalence and the type of sexual typologies for combined anal, oral and bisexual sex, (p=0.022), similar to anal and bisexual (p=0.008) and anal and oral (p=0.011). Failing to notify one’s partner of testing positive for an STI also had a significant association with STI prevalence [p=0.013].
The study concluded that STI prevalence among MSM on PrEP was associated with sexual typologies of anal, oral, and bisexual sex, and failing to notify one’s partners after turning positive for an STI.
The study recommends the Ministry of Health and partners reach MSM on PrEP with health services geared to lower the STI transmission rates and with persistent messaging encouraging continuous condom use and sharing of best strategies for and importance of partner notification.

Publication (Name of Journal)

African Journal of Health Science