RESEARCH ARTICLE x g d

Full list of author information is available at the end of the articleBackground Single-dose azithromycin has been recommended over a week-long doxycycline course as treatment for genital chlamydial infection, primarily because of concern about lack of adherence for the longer doxycycline course. However, the assumed superiority of azithromycin has been questioned [1]. In 2002, a meta-analysis concluded that azithromycin and doxycycline were equally effica-cious in treating urogenital chlamydial infection (with ef-ficacies of 97 % and 98 % respectively) [2], but a 2014 meta-analysis found a greater disparity, with efficacies of 94.3 % for azithromycin and 97.1 % for doxycycline [3]. For rectal infection, the difference may be greater: another sys-tematic review estimated treatment efficacies of 82.9 % for azithromycin and 99.6 % for doxycycline [4], with different delivery mechanisms being suggested as a possible reason for the difference [5]. Additionally, background use of tetracyclines but not macrolides has been found to be associated with lower chlamydia prevalence [6]. It has recently been proposed that autoinoculation (the inoculation of a site with infective bodies from an-other site on the same individual) of chlamydia from the gastrointestinal (GI) tract to the genital tract is possible in women, and that the GI tract may be a niche for persistent infection [7-9]. Mice orally infected with chlamydia de