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Chlamydia trachomatis infection



C. trachomatis infection is a common bacterial STI characterized primarily by urethritis in males and endocervicitis in females.
The obligate intracellular bacteria C. trachomatis is responsible for the disease and may be transmitted through oral, vaginal or anal sex.
Disease course
The most common manifestations include urethritis in men and mucopurulent cervicitis, urethritis, and endometritis in women. Disease progression may lead to pelvic inflammatory disease, which in pregnancy results in premature delivery and puerperal and neonatal infections.
Prognosis and risk of recurrence
C. trachomatis infection during pregnancy is associated with an increased risk of perinatal mortality (RR 1.84, 95% CI 1.15-2.94).


Key sources

The following summarized guidelines for the evaluation and management of Chlamydia trachomatis infection are prepared by our editorial team based on guidelines from the Center for Disease Control (CDC 2024), the International Union Against Sexually Transmitted Infections (IUSTI/BASHH 2016), and the U.S. Preventive Services Task Force (USPSTF 2014). ...
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Screening and diagnosis

Indications for screening, IUSTI/BASHH
As per BASHH/IUSTI 2016 guidelines:
Obtain annual C. trachomatis testing for all sexually active patients < 25 years of age.
Consider annual C. trachomatis testing for MSM.
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Diagnostic investigations

NAATs: as per BASHH/IUSTI 2016 guidelines, obtain NAATs (identifying C. trachomatis specific nucleic acid in clinical specimens) for diagnosis, due to their superior sensitivity, specificity, and speed.

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  • Testing for other STIs

Medical management

Management of uncomplicated urogenital infections, general population: as per BASHH/IUSTI 2016 guidelines, use one of the following agents as first-line treatment for uncomplicated C. trachomatis urogenital infections in patients who are not pregnant or breastfeeding:
doxycycline (100 mg PO BID, for 7 days)
azithromycin (1 g PO immediately, for one dose).
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  • Management of uncomplicated urogenital infections (pregnancy or breastfeeding)

  • Management of uncomplicated rectal/pharyngeal infections

  • Management of conjunctival infection

Patient education

General principles: as per BASHH/IUSTI 2016 guidelines, advise patients who test positive for C. trachomatis to abstain from sexual contact for seven days after they and their partners have completed treatment and their possible symptoms have resolved.

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  • Behavioral counseling

Preventative measures

Post-exposure prophylaxis: as per CDC 2024 guidelines, counsel MSM and transgender women who have had a bacterial STI (specifically syphilis, Chlamydia, or gonorrhea) in the past 12 months that doxycycline can be used as post-exposure prophylaxis to prevent these infections. Offer persons in this group a prescription for doxycycline post-exposure prophylaxis (200 mg, not to exceed 200 mg every 24 hours) after shared decision-making, to be self-administered within 72 hours after having oral, vaginal, or anal sex.

Follow-up and surveillance

Testing for cure
As per BASHH/IUSTI 2016 guidelines:
Avoid routine test of cure in patients treated with first-line regimens.
Perform a test of cure in pregnancy, in complicated infections, if symptoms persist, if second-line or third-line regimens have been used, or if non-compliance to therapy or re-exposure of infection is suspected.

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  • Testing for reinfection

  • Contact notification