Clinical Research Directory

Azithromycin Compared With Doxycycline for Treating Anorectal Chlamydia Trachomatis Infection Concomitant to a Vaginal Infection

Chlamydia trachomatis is the most commonly reported bacterial sexually transmitted infection (STI), especially among young women. Up to 75% of C. trachomatis infected women are asymptomatic. If untreated, C. trachomatis infection can cause sequelae such as pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility. C. trachomatis can also cause anorectal infections, which are typically asymptomatic. Among women with urogenital chlamydial infection, around 36-91% also had concurrent anorectal chlamydial. Notably, there was no association with anal intercourse in the studies that reported it. However, guidelines do not recommend routine anorectal testing, but restricted testing in people who are in high-risk groups, report anal sexual behavior, or have anal symptoms, i.e., on selective indications. This is in contrast to urogenital testing, which is a routine procedure in STI care services. The anal transmission of C. trachomatis in women may occur by autoinoculation from the vagina due to the close proximity of the vagina and the anus. C. trachomatis could lead to a persistent infection in the lower gastrointestinal tract, suggesting the potential role of autoinoculation of cervical chlamydial infection from the rectal site. Such (repeat) urogenital infections could lead to reproductive tract morbidity. Recommended treatments for C. trachomatis infections are a single 1g dose of azithromycin or 100mg of doxycycline 2 times a day for 7 days. Although these two regimens are equivalent for urogenital infection, no study has compared the effectiveness of these two treatments on anorectal infection. If rectal C. trachomatis is a hidden reservoir influencing transmission rates, and considering the potential complications of cervical infections, providing further evidence of the need for effective rectal treatments among women is highly relevant.