Abstract
Chlamydia trachomatis (CT) is the most common sexually transmitted bacterial infection globally, significantly affecting adolescent girls and young women (AGYW) in South Africa. This study investigated CT prevalence and genotypic diversity among 298 AGYW from Cape Town and Johannesburg, revealing an overall prevalence of 29.5%. Prevalence was higher in Cape Town (41.6%) compared to Johannesburg (17.4%; P < .0001). Genetic analysis identified 34 sequence types, including 15 novel variants. Longitudinal data highlighted frequent reinfections or persistent infections despite treatment. These findings underscore the importance of addressing CT's genetic diversity for improved reproductive health strategies and vaccine development.