Chlamydia

WA specific information

Chlamydia is the most commonly notified STI in WA and Australia.
This is a notifiable infection. Medical practitioners must complete the appropriate notification form for all patients diagnosed with a notifiable STI/HIV, as soon as possible after confirmed diagnosis.
It is a legal requirement to report all reasonable beliefs of child sexual abuse to the Department of Communities.
For treatment of adults and mature minors (aged 14 years or older) with, or who are sexual contacts of, chlamydia under a Structured Administration and Supply Arrangement, see Structured Administration and Supply Arrangement - CEO of Health SASA. This is suitable for use in a health service operated or managed by a Health Service Provider of the WA Department of Health, or contracted entity.
Real time WA and national (external site) notification data.
Free chlamydia testing is available from Get the Facts (external site)
Patient information: Chlamydia (HealthyWA)

Cause

Genital chlamydia infection is caused by some of the subtypes of Chlamydia trachomatis. Other subtypes cause trachoma and lymphogranuloma venereum (LGV).

Clinical presentation

85%-90% of people are asymptomatic so testing is important irrespective of symptoms.

The incubation period for symptomatic penile urethritis in is about 7 to 14 days but may be longer.

Uncomplicated sexually transmitted chlamydia can present with one or more of the following:

Urethral discharge (urethritis) and/or burning sensation (dysuria)
Cervical/vaginal discharge (cervicitis)
Anorectal infection (proctitis) is usually asymptomatic but can present with discharge, painful defecation, disturbed bowel function or irritation
Pharyngeal infection is usually asymptomatic
Conjunctivitis

Untreated sexually transmitted chlamydia can lead to complications including:

Pelvic inflammatory disease (PID) which can present with dyspareunia (pain during vaginal intercourse), intermenstrual or post-coital bleeding, discharge, and in the long-term, tubal infertility and ectopic pregnancy
Epididymo-orchitis presenting as painful testicular swelling (uncommon)
Peri-hepatitis (abdominal pain, fever, tender liver)
Reactive arthritis
Premature rupture of membranes, preterm delivery

Chlamydia transmitted vertically (via birth canal) can cause neonatal conjunctivitis and pneumonitis.

STI Atlas (external site)

Diagnosis

Chlamydia infection is diagnosed by detecting Chlamydia trachomatis from anatomical sites appropriate to the patient’s sexual practices. For example:

If the patient has had receptive anal sex, oro-anal sex, rimming or fingering, collect a rectal swab.
If the patient has had receptive oral sex, take a throat swab.

If the patient presents with a positive self-test result, ensure it is confirmed with a laboratory test.

Site	Specimen	Test	Notes
Penile urethra	First void urine (FVU) - first part of the urine stream, it can be done at any time and does not have to be the first void of the day.	Nucleic acid amplification test (NAAT)	SeeSTI self-testing card (PDF 716KB) for collection instructions
Vagina	Self-obtained lower vaginal swab (SOLVS)	NAAT¹	SeeSTI self-testing card (PDF 716KB) for collection instructions
Cervix	Clinician-collected endocervical swab	NAAT¹	Recommended for patient with symptoms of cervicitis or PID
Rectum	Clinician- or self-collected rectal swab	NAAT¹	SeeSTI self-testing card (PDF 716KB) for collection instructions
Throat	Clinician-collected throat swab	NAAT¹	See page 2 of STI self-testing card (PDF 716KB) for instructions on throat swab collection
Conjunctiva	Clinician-collected conjunctival swab	NAAT¹

1. Dry swab, no transport medium

Management

Offer patient information https://www.healthywa.wa.gov.au/Articles/A_E/Chlamydia

Infection

Antibiotic^{1, 2}

Important considerations

Adults (not pregnant)

Adults (pregnant)

See Australian categorisation system for prescribing medicines in pregnancy (external site)

Uncomplicated genital or pharyngeal (throat) chlamydia

Doxycycline 100 mg orally, 12-hourly for 7 days This is the preferred treatment as it reduces opportunities for M. genitalium to develop resistance to azithromycin and is effective against asymptomatic rectal carriage of C. trachomatis

OR

Azithromycin 1 g orally, as a single dose

Where there is any concern that the patient will not be compliant with doxycycline, azithromycin may be more suitable.

Azithromycin 1 g orally, as a single dose

Perform a full STI check-up including HIV and syphilis serology if not done as part of initial testing
Advise no sexual contact for 7 days after treatment is commenced, or until the course is completed and symptoms resolved, whichever is later
Advise no sex with partners from the last 6 months until the partners have been tested and treated if necessary
Contact tracing and consider presumptive treatment if there has been sexual contact within the past 2 weeks or when the person’s individual circumstances mean later treatment may not occur (see contact tracing section for more information)
Provide patient information
Notify WA Health
It is a legal requirement to report all reasonable beliefs of child sexual abuse (external site) to the Department of Communities

Rectal chlamydia

Doxycyline 100mg orally, twice daily for 7 days; if LGV detected treat for 21 days if symptomatic

OR

Azithromycin 1g orally, then another dose (1g) given 12-24 hours later

Pelvic inflammatory disease (PID)

See PID

Epididymo-orchitis

See epididymo-orchitis

Lymphogranuloma venereum (LVG)

See lymphogranuloma venereum (LGV).

1. For treatment of adults and mature minors (aged 14 years or older) under a Structured Administration and Supply Arrangement, see Structured Administration and Supply Arrangement - CEO of Health SASA. This is suitable for use in a health service operated or managed by a Health Service Provider of the WA Department of Health, or contracted entity

2. Seek specialist advice if patient is a child

Contact tracing

Contact tracing (external site) is important to prevent re-infection and reduce transmission.
All partners should be traced back for 6 months.
The diagnosing doctor is responsible for initiating and documenting a discussion about contact tracing.
Offer testing of exposed anatomical sites to all sexual contacts.
Consider presumptive treatment if there has been sexual contact within the past 2 weeks or when the person’s individual circumstances mean later treatment may not occur.
For empirical treatment of sexual contacts who are adults and mature minors (aged 14 years or older) under a Structured Administration and Supply Arrangement, see Structured Administration and Supply Arrangement - CEO of Health SASA. This is suitable for use by Registered Nurses and Aboriginal Health Practitioners employed by a health service operated or managed by a Health Service Provider of the WA Department of Health, or contracted entity.
See Australasian contact tracing guidelines (external site)

Follow up

Follow up is important to:

confirm patient adherence with treatment and assess for symptom resolution,
confirm contact tracing has been undertaken or offer more contact tracing support, and
educate about condom use, contraception, HIV PrEP/PEP, Doxy PEP (see below), safe injecting practices, consent, cervical screening, and vaccinations for HAV, HBV, HPV and mpox as indicated.

Test of cure is recommended:

for pregnant people,
for rectal chlamydia treated with azithromycin,
if there is doubt about compliance with treatment and advice, or
if symptoms persist

As NAAT can remain positive 3-4 weeks after treatment, repeat testing should be undertaken no earlier than 4 weeks after treatment.

Test for re-infection is recommended 3 months after treatment as re-infection is common and provides an opportunity to repeat tests for syphilis, HIV and HBV after the window period.

Free chlamydia testing is available from https://www.getthefacts.health.wa.gov.au/online-sti-testing