Information
Editors
Chlamydia
Essentials
- Diagnose and treat the infection in time to avoid the possible complications of prolonged or recurrent infection (pelvic inflammatory disease, infertility, ectopic pregnancy).
- Prevent the spread of the chlamydial infection by examining and treating the sexual partners of the infected patient.
Early symptoms
- The incubation period from chlamydial infection to the possible emergence of symptoms is 1-3 weeks, i.e. longer than in gonorrhoea. The majority of those infected are asymptomatic.
- In men, urethritis is marked by scant, watery (later mucous) discharge from the urethra and dysuria. In women, there is dysuria, pollakiuria and mild leucorrhoea. Cervicitis is a relatively common finding. It is manifested as mucopurulent discharge and oedema or bleeding tendency of the orifice of the uterus.
- Infections of the pharynx and anus are often asymptomatic.
Late symptoms and complications
- In women, prolonged chlamydial infection may result in endometritis and salpingitis. These conditions are not always associated with severe symptoms; the patient may have just slight fever or mild lower abdominal pain. Endometritis may also cause irregular uterine bleeding.
- Pelvic inflammatory disease (PID Pelvic Inflammatory Disease (Pid)) is a late complication sometimes requiring inpatient treatment. Perihepatitis is a rare complication of chlamydial infection.
- Late complications of extensive and, especially, recurrent chlamydial infection also include tubal damage which in turn causes infertility and ectopic pregnancies.
- In men, chlamydial infection is an important cause of epididymitis Testis Pain, whereas the etiological significance of chlamydia in prostatitis is considered small.
- Chlamydial infection can trigger the development of reactive arthritis (uroarthritis, Reiter's disease Reactive Arthritis) in both men and women.
Diagnostics
Clinical symptoms and signs
- Chlamydial infection can be suspected but never diagnosed on the basis of symptoms alone.
- Threshold for testing should be low if the patient has
- another STD or a history of previous chlamydial infection
- numerous sexual partners or a new one
- urinary leucocytosis without bacterial growth
- recurrent urinary tract infections or post-coital bloody discharge (female patient).
Laboratory diagnostics
- A chlamydial infection is detected by a nucleic acid detection test Laboratory Testing for Chlamydia Trachomatis and Neisseria Gonorrhoeae.
- Today chlamydia and gonorrhoea can be analysed on the same sample.
- First-void urine samples are used for chlamydial diagnostics particularly in men. Samples are taken when at least 5-7 days have passed since the potential time of acquirement of infection. The patient has to refrain from voiding for 2 h before urine sampling. The sample will keep at room temperature for up to 30 days.
- As an alternative to first-void urine in men, swab samples may be obtained from the urethra.
- In women, a swab sample obtained from the vagina is more sensitive than first-void urine.
- Depending on the mode of transmission, samples should also be obtained from throat and anus.
- If the patient has conjunctivitis, the sample may also be obtained from conjunctiva.
- First-void urine samples are well suited for testing at home.
- In the laboratory, also the patient him/herself can take the swab from the vagina or anus.
- Chlamydial serology may be useful in chronic infections. High IgG antibody titres are often present in pelvic infections and also in other complications. An isolated positive test indicates that the patient has a history of chlamydial infection.
Post-treatment follow-up and tracing of contacts
- A follow-up specimen should be collected from the anatomic sites where the infection has been detected, a first-stream urine specimen in urethritis, otherwise a mucosal sample 4 weeks after the end of treatment because re-testing too early may produce a false positive result.
- A permanent sexual partner should be simultaneously treated. Treatment can be started immediately after obtaining the sample. At the same time, other possible STDs should be tested for and contact tracing performed.
- The treating physician is required to trace the sexual contacts of their patients. During the follow-up visit, the physician should enquire the index patient whether the person who is the source of the infection and any persons potentially infected have been tested for chlamydia and received treatment as needed. If desired, the attending physician may delegate the screening of sexual partners to a physician responsible for communicable diseases.
- Tracing the contacts of the patient is the most effective way of combating the STDs.
- In association with an induced abortion
- In early pregnancy
- In a patient less than 25 years of age seeking contraception, either on the first visit or on the follow-up visit after 3 months and again after 12 months
- On a follow-up visit related to contraception if there is a new sexual partner or the patient has a history of previous chlamydial infection
References
- White JA, Dukers-Muijrers NH, Hoebe CJ, et al. 2025 European guideline on the management of Chlamydia trachomatis infections. Int J STD AIDS 2025;():9564624251323678. Online ahead of print.
- Centers for Disease Control and Prevention. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae--2014. MMWR Recomm Rep 2014;63(RR-02):1-19. [PubMed]