Evaluation of a community-based aetiological approach for sexually transmitted infections management for youth in Zimbabwe: intervention findings from the STICH cluster randomised trial

BACKGROUND: Young people are at high risk of sexually transmitted infections (STIs). We report STI testing uptake, prevalence and incidence within a community-based integrated HIV and sexual and reproductive health service for youth, being evaluated in a cluster randomised trial in Zimbabwe. METHODS: This paper reports the intervention findings of the cluster randomised trial whereby STI testing was offered to all service attendees (16–24 years) in 12 intervention clusters over 12 months between October 5, 2020, and December 17, 2021, in Zimbabwe. Testing for Chlamydia trachomatis [CT] and Neisseria gonorrhoeae [NG] was offered to males and females with results available in one week and follow-up of test-positive clients by telephone. Trichomonas vaginalis [TV] testing was offered to females only with same day results and treatment. Youth testing positive for any STI were offered partner notification slips and free treatment for partners. This trial was registered with ISRCTN Registry, ISRCTN15013425. FINDINGS: Overall, 8549/9891 (86.1%) eligible youth accepted CT/NG testing. Prevalence of CT and NG was 14.7% (95% CI 13.6–15.8) and 2.8% (95% CI 2.2–3.6) respectively. Combined prevalence of CT, NG or TV in women was 23.2% (95% CI 21.5–25.0). After adjusting for cluster, age and sex, the odds of NG were increased in those living with HIV (aOR 3.14, 95% CI 2.21–4.47). The incidence rate among those who initially tested negative for CT or NG was 25.6/100PY (95% CI 20.6–31.8). CT/NG treatment uptake was 924/1526 (60.6%). TV treatment uptake was 483/489 (98.8%). A partner returned for treatment for 103/1807 clients (5.7%). INTERPRETATION: Our findings show high acceptability of STI testing among youth. STI prevalence was high particularly among females and youth with HIV, underscoring the need for integration of HIV and STI services. FUNDING: 10.13039/501100000265MRC/10.13039/501100000269ESRC/10.13039/501100000278DFID/10.13039/501100000272NIHR (MR/T040327/1) and 10.13039/100010269Wellcome Trust (206316/Z/17/Z).