HIV pre-exposure prophylaxis (PrEP) programmes in Africa reach young women at risk of sexually transmitted infections (STIs). We evaluated curable STI prevalence, incidence and risk factors among women initiating PrEP.
From August to December 2022, sexually active women aged 16–30 years from 15 South African sites, and one site each in Eswatini, Kenya, Malawi, Uganda and Zambia were enrolled into the INSIGHT cohort and offered oral emtricitabine/tenofovir PrEP with follow-up at 1, 3 and 6 months. At each visit, STI symptoms were assessed and treatment provided based on syndromic management or diagnostic testing. Diagnostic tests included nucleic acid amplification for Chlamydia trachomatis and Neisseria gonorrhoeae, the rapid OSOM for Trichomonas vaginalis at enrolment and month 6, and serological testing for syphilis at enrolment using rapid plasma reagin with confirmatory Treponema pallidum particle agglutination. Prevalence and incidence of each STI were calculated, and predictors assessed using multivariable regression.
Of 3087 participants offered daily oral PrEP with a median age of 23 (IQR 21–27), 3011 had STI results and 30.9% had one or more STIs, with 15.7% reporting symptoms. The prevalence of C. trachomatis, N. gonorrhoeae, T. vaginalis and syphilis was 20.8%, 6.8%, 6.0% and 4.4%, respectively. The incidence of one or more STIs (C. trachomatis, N. gonorrhoeae or T. vaginalis) was 49.3/100 person-years (95% CI 45.3 to 53.4) with 12.7% reporting symptoms. The incidence of C. trachomatis was 30.6/100 person-years (95% CI 27.5 to 33.7), N. gonorrhoeae 10.8/100 person-years (95% CI 9.0 to 12.6) and T. vaginalis 11.5/100 person-years (95% CI 9.7 to 13.4). An incident STI diagnosis was associated with low alcohol use (adjusted incidence rate ratio (aIRR) 1.3; 95% CI 1.0 to 1.6) and moderate alcohol use (aIRR 1.4; 95% CI 1.1 to 1.8), and having an STI diagnosed at enrolment (aIRR 1.8; 95% CI 1.5 to 2.1).
The high prevalence and incidence of STIs among African women initiating PrEP, most of whom did not report symptoms, highlights the need for aetiologic testing to detect STIs, guide treatment and reduce reproductive health sequelae and risk of transmission.
clinicaltrials.gov NCT05746065.