*3.1.2 Treatment of urogenital and extra-genital infections due to* C. trachomatis

In this section, the management of chlamydia and LGV will be discussed in detail.

#### *3.1.2.1 General approach to chlamydia disease and treatment options*

The key to the management of chlamydia starts with clinical suspicion. Patients who have chlamydia disease may present with urinary symptoms and might be misdiagnosed as urinary tract infections. Also, patients who experienced sexual assault or sexually active adolescents may be reluctant to give the right information or may be unaware of the situation. Therefore in case of doubt about chlamydia, clinicians should immediately initiate diagnostic methods and send appropriate clinical specimens to the laboratory for testing. Moreover, co-infection with other STIs including gonorrhea, HIV, and syphilis must be investigated [49]. Early appropriate antibiotic therapy is important and the patient's age, pregnancy status, access to medication, and treatment compliance should all be taken into account. In case of severe PID, consultation with obstetrics/gynecology and in case of ocular involvement consultation with ophthalmology should be performed. In order to prevent reinfection, patients should be informed about safe sex practices and the necessity of partner management. Finally, a patient-based follow-up test strategy should be determined after the completion of treatment [45].

For treatment purposes, chlamydia is mainly categorized into two forms according to the anatomical site involved. Oropharyngeal and lower genital tract involvement (cervicitis/urethritis/epididymitis/anorectal infection) are defined as uncomplicated disease, whereas upper genital tract involvement [salpingitis/endometritis/pelvic inflammatory disease (PID), Fitzhugh-Curtis syndrome] is defined as a complicated disease.

The laboratory diagnosis of chlamydia has significantly improved as a result of the switch from culture-based to molecular-based testing procedures [50]. Because of its high sensitivity, high specificity, and convenience to be utilized on a variety of clinical specimen types, nucleic acid amplification testing (NAAT) is the most efficient method [45, 51, 52]. Unfortunately, NAAT may not always be available in every facility and patients who are at risk for STIs may sometimes be unlikely to return for test results; therefore, WHO recommends consideration of a syndromic approach (to detect and treat patients with STIs based on particular symptoms and signs, which are indicators of infection) in these situations [43, 53]. Also when administering singledose or multidose regimens to patients, medicine should be given with the first dosage being closely monitored on-site and in the clinic [43].

Doxycycline 100mg, orally, twice a day for 7 days (or delayed release 200 mg tablet, once a day for 7 days) is the recommended regimen for non-pregnant adults and adolescents with uncomplicated chlamydia involving cervical, urethral, rectal, and oropharyngeal sites. Oral azithromycin 1 g single-dose is the alternative treatment regimen for uncomplicated chlamydia. Previously, single-dose azithromycin had been another preferred option due to its high efficacy against *C. trachomatis,* better adherence due to once-daily usage, and similar adverse effect profiles. However, mounting evidence suggests that azithromycin has a lesser rate of microbiologic cure than doxycycline especially in treating rectal and oropharyngeal infections, and currently, it is accepted as the alternative treatment option [45].

According to a meta-analysis and a Cochrane systematic review that included men with urogenital chlamydia, a 7-day course of doxycycline achieved higher success rates than single-dose azithromycin regimens [54, 55]. Furthermore, as shown by two randomized, double-blind clinical trials and several nonrandomized studies doxycycline regimen may be 20% more effective than azithromycin in managing rectal *C. trachomatis* infection in both women and men who have sex with men (MSM) [54, 56–59].
