The Natural History of Rectal Gonococcal and Chlamydial Infections: The ExGen Study. (6th August 2021) - Barbee, Lindley A
Abstract: Background: The duration of rectal gonococcal and chlamydial infection remains unknown. This basic epidemiologic parameter is needed to understand transmission dynamics. Methods: We conducted a prospective, longitudinal, observational cohort study of 140 men who have sex with men (MSM) at risk of gonorrhea and chlamydia acquisition. For 48 weeks, enrolled men collected rectal swabs (Aptima multi-test kit) at home and responded to an electronic survey about sexual behavior and health conditions weekly. Swabs remained untested until participants completed the study. We used Kaplan-Meier estimates to determine the median duration of infection, censoring infections for treatment, loss to follow-up, and end-of-study. We used log-rank test to compare duration of infection by human immunodeficiency virus (HIV) status, history of infection with gonorrhea or chlamydia, and coinfection with the other pathogen. Results: 140 enrolled MSM contributed 70.5 person-years of follow-up. Eighteen men had 20 incident rectal gonococcal infections, which persisted for 2–23 weeks; 30% were censored for treatment. The estimated median duration of rectal gonorrhea was 9 weeks (95% confidence interval [CI]: 3–12 weeks). Twenty-four men experienced 32 rectal chlamydial infections, persisting between 2 and 42 weeks; 60% were censored. The estimated duration of rectal chlamydia was 13 weeks (95% CI: 6 weeks–undefined). There were no differences in the duration of rectal gonorrhea or chlamydia by HIV status, history of chlamydia/gonorrhea, or coinfection. Conclusions: On average, rectal gonorrhea and chlamydial infections last 2–3 months, although some infections persisted for 6–11 months. Further understanding into predictors of persistence is needed. Abstract : Using weekly at-home, self-collected rectal Nucleic Acid Amplification Tests over a 48-week study period, we estimated the duration of rectal gonorrhea and chlamydia to be 9 and 13 weeks, respectively, in a cohort of Men who have Sex with Men at risk of sexually transmitted infections.