Chlamydia is the most common bacterial sexually transmitted disease (STD) worldwide and in the Netherlands, caused by the bacterium Chlamydia trachomatis (CT). When a woman is infected, in most cases (70% to 80%) she does not notice it. This increases the chance of infecting someone else with Chlamydia. Also, a woman without symptoms can later develop pelvic inflammatory disease, which is treatable with antibiotics, and may result in serious complications as ectopic pregnancy and tubal infertility.

FemCure

Following the insight, halfway through the last decade, that CT not only infects the vagina, but also the anus, the study FemCure was started. "The anal infection usually goes unnoticed, because in clinical and public sexual health care practice, we don't routinely test women anorectally. Because the anal infection is common, we wanted to gain more insight into its clinical and public health impact to inform best practical control strategies”, says Nicole Dukers-Muijrers who coordinated the study.

Treatment

The FemCure study showed that the antibiotic Doxycycline proved highly effective to eradicate the bacterium at all anatomic sites (genital, anorectal and oral). The study also showed high treatment failure (>20%) for anal CT when treated with azithromycin (routine care) and showed that self-contamination (i.e., where Chlamydia migrates between the anal and vaginal site) may play an important role in the persistence of Chlamydia in a previously treated woman.  “These findings may have implications for our clinical and public sexual health care strategies, such as treating Chlamydia with doxycycline, and irrespective of anatomic site of infection, because women with vaginal chlamydia in most cases will have an (undiagnosed) anal Chlamydia”, Nicole explains.