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

Summary

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.

Timeline

Start

2018-10-10

Primary completion

2020-08-17

Completion

2020-08-17

Publications

• Results Peuchant O, Lhomme E, Martinet P, Grob A, Baita D, Bernier C, Gibaud SA, Le Hen I, Le Naour E, Trignol-Viguier N, Lanotte P, Lefebvre P, Vachee A, Girard T, Loubinoux J, Bebear C, Ghezzoul B, Roussillon C, Kret M, de Barbeyrac B; CHLAZIDOXY Study Group. Doxycycline versus azithromycin for the treatment of anorectal Chlamydia trachomatis infection in women concurrent with vaginal infection (CHLAZIDOXY study): a multicentre, open-label, randomised, controlled, superiority trial. Lancet Infect Dis. 2022 Aug;22(8):1221-1230. doi: 10.1016/S1473-3099(22)00148-7. Epub 2022 May 9.
• Results Rank RG, Yeruva L. Hidden in plain sight: chlamydial gastrointestinal infection and its relevance to persistence in human genital infection. Infect Immun. 2014 Apr;82(4):1362-71. doi: 10.1128/IAI.01244-13. Epub 2014 Jan 13.
• Results Kong FY, Tabrizi SN, Fairley CK, Vodstrcil LA, Huston WM, Chen M, Bradshaw C, Hocking JS. The efficacy of azithromycin and doxycycline for the treatment of rectal chlamydia infection: a systematic review and meta-analysis. J Antimicrob Chemother. 2015 May;70(5):1290-7. doi: 10.1093/jac/dku574. Epub 2015 Jan 29.
• Results Kong FY, Hocking JS. Treatment challenges for urogenital and anorectal Chlamydia trachomatis. BMC Infect Dis. 2015 Jul 29;15:293. doi: 10.1186/s12879-015-1030-9.
• Peuchant O, Lhomme E, Kret M, Ghezzoul B, Roussillon C, Bebear C, Perry F, de Barbeyrac B; and the Chlazidoxy study group. Randomized, open-label, multicenter study of azithromycin compared with doxycycline for treating anorectal Chlamydia trachomatis infection concomitant to a vaginal infection (CHLAZIDOXY study). Medicine (Baltimore). 2019 Feb;98(7):e14572. doi: 10.1097/MD.0000000000014572.

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