Chlamydia Trachomatis (CT) is the most common bacterial STI. It is most common in those <30, and is often asymptomatic.
It is simple to test for and to treat. Previous infection does not give immunity and re-infection can occur.
- It is the most common bacterial STD
- 10% of sexually active adults aged 15-25
- Accounts for 40% of Non-Gonococcal urethritis in men
- It is highly infectious – and will infect in >50% of exposures – i.e. if you have intercourse with an infected individual on only one occasion, your risk of contracting chlamydia is >50%
- Urethritis (frequency and dysuria on micturition)
- Testicular pain
- 50% of cases are asymptomatic
- Reactive arthritis
- 80% of cases are asymptomatic
- Vaginal discharge
- Post-coital (after sex) bleeding
- Intermenstrual bleeding
- Lower abdominal / pelvic pain
- Infection tends to occur in the endocervical canal
- May acquire infection from the mother – resulting in conjunctivitis and pneumonia.
- Can affect the throat, eye and anus
- o Epididymitis
- o Rectal infection: Proctitis
- o Reiter’s disease – aka Reactive Arthritis
- Rare, as chlamydial infection usually diagnosed before it progresses this far
- Reactive arthritis is an autoimmune reaction that occurrs in reponse to bacterial infection – usually chlamydia, and also common atfer gastroenteritis
- Consists of the triad of:
- Oligoarthritis – “can’t bend the knee”
- Conjunctivitis – “can’t see”
- Urethritis – “can’t pee”
- Salpingitis – infection of the fallopian tubes
- Neonatal conjunctivitis
- Typically presents at 2-4 weeks
- Treated with oral erythromycin (syrup)
- Rarely causes blindness in the developed world. In Africa, a different strain is more prevalent, which is much more likely to result in blindness
- LCR and PCR – about 90% sensitive
- These gene amplification tests are also sometimes referred to as NAAT (Nucleic acid amplification).
- ELISA – about 40% sensitive
Typically gonorrhoea is also tested for on the same sample
- Age <30 and sexually active – opportunistic screening
- New partner in the last 12 months
- Have had STI in past 12 months
- Parter with STI
- Is at risk of complications of STI, e.g.:
- Before IUD insertion
- before termination of pregnancy
- Symptoms or signs suggestive of chlamydia
- Patient request for sexual health check
- Men – first void (of the day) urine sample, and/or urethral swab.
- Women – usually cervical swab, but an additional 20% of cases can be identified with urethral swab. Urine samples are notoriously inaccurate in females.
- Taking a swab from a female – this is slightly different from the technique for gonorrhoea. Again, take a sample whilst using a speculum. There are two different swab sizes, and the larger should be used, unless the os is too small to allow passage, in which case the smaller swab (also used for male urethral sampling) may be used. The swab should go inside the cervical os, and then be rotated completely 3x.
- Urethral swab – the disease does not normally exist only in the urethra, however, if it is present in the endocervical region, there is a chance it may also be present in the urethra
- Throat swabs, anal swabs and eye swabs can all be sent for NAAT if chlamyida is suspected
- Doxycycline – 100mg/12 hours PO for 7 days OR
- This, and other tetracycline are contra-indicated in pregnancy
- Azithromycin – 1g single dose PO
- Advise no sexual contact for 7 days after treatment
- Advise no sex with partners from the last 6 months until partners have been tested (and treated if required)
- Advise about contact tracing
- Trace partners for the last 6 months
- Offer treatment to all sexual contacts
- Provide written information factsheet
- In Australia – notify the state or territory health department (notifiable disease)
Advised at one week and again at 3 months.
Follow-up at one week to ensure:
- Partner tracing has occurred, or offer support for this
Test of cure (TOC) is not routinely recommended, unless:
- Patient is pregnant, OR
- Rectal chlamydia
Perform repeat NAAT testing 4 weeks after finishing treatment if indicated
- Although not an official ‘screening’ program, the NHS promotes free chlamydia and gonorrhoea testing in the R U Clear campaign.
- Eligible to under 25’s
- Text (SMS) details to the service, and they send out a pack in the post
- ‘Pee in the pot’ and send it back
- Results sent out via SMS text messaging
- Although urethral swab (men) and endocervical swab (women) is the best way of detecting chlamydia, the urine test is deemed accurate enough in an environment of such high prevalence of STD.
- In Australia:
- It is recommended to screen all sexually active people aged 15-29 annually for chlamydia (+/- gonorrhea)
- There is no ‘official’ screening programme – instead it is recommended that health professionals (especially GPs) opportunistically offer screening to those aged 15-29 when they present for whatever reason
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy
- Australian STI guidelines - Chlamydia