(P491) Prevalence and incidence of sexually transmitted infections among adolescents and young adults in rural KwaZulu-Natal, South Africa

Background

Adolescents and young adults (AYA) in South Africa (SA) have a high burden of HIV and curable sexually transmitted infections (STIs). Integrated sexual and reproductive health (SRH) services, including STI testing and sexual health promotion, may decrease both transmissible HIV and the prevalence and incidence of STIs.

Methods

The Isisekelo Sempilo trial [NCT04532307] was a 2x2 factorial randomized controlled trial conducted March 2020-August 2022 in a randomly selected sample of 16-29-year-olds from a population surveillance area in rural KwaZulu-Natal, SA. Participants were randomized to four arms: 1) enhanced Standard of Care: study-organized adolescent youth friendly services (AYFS) for integrated sexual health and differentiated HIV prevention; 2) SRH: baseline STI testing with referral to AYFS; 3) peer navigator: needs assessment, tailored sexual health promotion, condom provision, and facilitation of AYFS attendance; 4) combined SRH and peer navigator. Participants in all arms were offered STI testing at 12 months with self-collected specimens for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis using Cepheid GeneXpert.



Results

Prevalence of any STI at baseline was 179/800 (22.4%). At 12 months, prevalence of any STI among those willing and able to provide specimens (936/1281, 73%) and with complete results (927/936, 99%) was 209/927 (22.6%): 163/927 (17.6%) chlamydia, 54/927 (5.8%) gonorrhea, and 44/931 (4.7%) trichomoniasis. Twelve-month STI prevalence did not significantly differ between arms with and without the peer navigator intervention (aOR adjusted for sex, age, and location: 0.77, 95%CI 0.57-1.05, p=0.10) or SRH intervention (aOR 0.74, 95%CI 0.56-1.06, p=0.12). Among those with STI testing at both timepoints, 52 (14.5%) of 358 participants who tested negative at baseline acquired a new STI by 12 months, and 38/467 (8.1%) were diagnosed with the same STI at baseline and 12 months. The proportions of new and repeat infections did not differ between arms with and without the peer navigator intervention (p=0.40 and p=0.38, respectively).



Conclusion

AYA in rural SA have high STI prevalence and incidence, despite peer navigation and access to SRH through AYFS. More intensive interventions such as repeat screening, expedited treatment, and partner notification services may be needed to reduce STI prevalence and incidence in this setting.