Background Information

Aetiology

Chlamydia is caused by the infection of the obligate intracellular bacterium Chlamydia trachomatis

Epidemiology

Chlamydia is the most commonly reported curable bacterial STI in the UK

Risk factors include:

• <25 y/o
• New sexual partner
• >1 sexual partner in the last year
• Lack of consistent condom use

Clinical Features

Genital Infection

Chlamydia is asymptomatic in ~70% of women and ~50% of men

Extra-Genital Infection (Less Common)

Complications

Possible complications include:

• PID – in women (see the Pelvic Inflammatory Disease (PID) article)
• Epididymo-orchitis – in men (see the Epididymo-Orchitis article)
• Reactive arthritis
• Fitz-Hugh syndrome (peri-hepatitis)

Chlamydia infection in pregnancy is associated with adverse outcomes, including:

• Increased risk of premature rupture of membranes, pre-term delivery, and low birth weight in the infant
• Increased risk of intra-partum pyrexia and late post-partum endometritis
• Infections of the eyes, lungs, nasopharynx, and genitals in the neonate (much more serious compared to adults)

Diagnosis

Screening

According to the National Chlamydia Screening Programme (NCSP), the following should be offered a chlamydia test:

• Partner with chlamydia or symptoms of chlamydia infection
• All sexually active women <25 y/o (to be tested yearly and after having sex with a new partner)
• All sexually active women <25 y/o who attend a sexual health service / contraception service / termination of pregnancy service

Chlamydia Testing

Test of choice: NAAT

Sample collection methods:

• Male: first pass urine (alternative: urethral swab)
• Female: vulvovaginal swab (alternative: endocervical swab or first pass urine)

Management

Refer ALL patients to GUM clinic / local specialist for management.

General Advice

Abstain from all sexual activity until 7 days after they and their partner(s) have completed treatment

Pharmacological Management

• 1st line: oral doxycycline 100mg BD for 7 days
• 2nd line: oral azithromycin 1g OD for 1 day followed by 500mg OD for 2 days
• 3rd line: oral erythromycin

Management in Pregnant Patients

• Discuss with GUM and specialist
• Safe antibiotic options include: azithromycin, erythromycin, amoxicillin
• Test of cure is routinely needed in pregnant patients

Partner Notification

Partner notification period:

• If symptomatic men → notify all partners within the past 4 weeks (1 month) (or most recent partner if more than 4 weeks ago)
• If all other patients (i.e. asymptomatic men and women) → notify all partners within the past 6 months

Management of sexual contacts:

• Any sexual partner who tests positive for Chlamydia trachomatis should receive treatment
• Offer full STI screening, including HIV testing (and hepatitis B screening and vaccination if indicated)

Follow Up

Test of Cure

Test of cure is NOT routinely recommended.

Exceptions:

• Pregnant patients
• Poor compliance
• Persistent symptoms

Test of cure should be performed at least 3 weeks after completion of treatment.

Repeat Testing

Indications:

• Offer to all <25 y/o diagnosed with chlamydia, 3-6 months after completion of treatment
• Consider if >25 y/o who are at high risk of re-infection

References