Men and Women Have an Equal Oropharyngeal and Anorectal Chlamydia trachomatis Bacterial Load: A Comparison of 3 Anatomic Sites.

ABSTRACT

BACKGROUND: The Chlamydia trachomatis bacterial load could have impact on transmission and sequelae. This is the first study providing comparison of C. trachomatis load at 3 anatomic sites estimated by cycle quantification (Cq) values. METHODS: Data from 7900 C. trachomatis-positive samples were included (2012-2018). Cq value was used as an inversely proportional measure for C. trachomatis load. Multivariable linear regression analyses assessed differences in mean Cq values. RESULTS: Vaginal swabs had the lowest Cq values (31.0) followed by urine (32.5), anorectal swabs (34.0), and oropharyngeal swabs (36.8) (P < .001). Men and women had similar oropharyngeal (36.4 vs 37.3; P = .13) and anorectal (34.2 vs 33.9; P = .19) Cq values. Men (32.2) and women (30.7) aged <25 years had lower urogenital Cq values than men (32.8) and women (31.9) aged ≥25 years (P < .001). HIV-positive patients had higher urogenital Cq values than HIV-negative patients (33.8 vs 32.6; P < .03). CONCLUSIONS: Men and women have a similar C. trachomatis load at extragenital locations arguing for similar transmission potential and clinical relevance. Older patients and HIV-coinfected patients had lower C. trachomatis load, suggesting exposure to previous C. trachomatis infections potentially leading to partial immunity reducing load.