Nieuwe aanpak is nodig in de strijd tegen chlamydia

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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.

Another interesting question is how we can control Chlamydia on a population level. “The clinical and public health relevance of widespread case finding by testing for asymptomatic Chlamydia infections is under debate”¹, Nicole says. ”There is no practice-based evidence that population prevalence of CT nor the number of serious complications can be reduced by age-based screening programmes or by widespread testing for chlamydia in asymptomatic persons. We need to weigh benefits and harms of large-scale testing of asymptomatic women. Most infections will never lead to serious complications, and there is a risk of overtreatment because the infection may already have spontaneously cleared. Also, importantly there is a risk of antibiotic resistance in bacteria other than CT”.

According to Nicole, the future of Chlamydia control is not in mass testing of asymptomatics. We need to shift our focus from attempting to reduce the infection at the population level, to identifying and providing comprehensive sexual health care for women who are at increased risk of complications. Herein is more targeted testing (e.g. in people who meet the diagnostic criteria [see CSH]) combined with effective management strategies, including optimal treatment and partner notification, and prevention, such as behavioural counselling and information, a way forward¹.