Syphilis

There is currently a syphilis outbreak in WA. For further information on the outbreak visit WA Syphilis outbreak response
WA specific information
Cause
Syphilis is caused by Treponema pallidum, subspecies pallidum.
Clinical presentation

Most people notified with syphilis in WA do not present with symptoms but are diagnosed by syphilis serology, highlighting the importance of offering opportunistic syphilis testing to sexually active people. 

As syphilis can present in many ways, consider syphilis in all patients with unexplained symptoms. 

 

  Stage of syphilis
   Primary Secondary Early latent Late latent Tertiary
Incubation period 9 to 90 days, average 3 weeks 2-24 weeks, average 6 weeks, less than 2 years after infection - - Years
Infectivity High to sexual partners and vertically via placenta to fetus Not transmissible sexually but vertical transmission to fetus possible -
Clinical signs

Ulcer (chancre) at the point of entry - genital, anal or oral

Usually a single painless ulcer with a firm (indurated) base. However, atypical presentations, e.g. multiple ulcers, painful ulcers, are common

Heals spontaneously within weeks even without treatment

Lymph nodes that drain the anatomical site of the chancre may be enlarged, rubbery and non-tender

Fever, malaise, headache and lymphadenopathy

Skin involvement in >90% e.g. rash, hair loss, eyebrow loss, mucous patches (oral and genital), condylomata lata (ano-genital wart-like growths, can be misdiagnosed as genital warts)

Early neurosyphilis

Syphilis acquired in the past 2 years and no symptoms Syphilis acquired more than 2 years ago and no symptoms 

Very rate

Can affect skin, cardiovascular (ascending aortic aneurysm), musculoskeletal (bones, joints) and neurological (dementia, meningitis, nerve palsy) systems

Syphilis complications

Early neurosyphilis can present with visual deficits, tinnitus, deafness, cranial nerve palsy, meningitis

Congenital syphilis can cause spontaneous abortion, stillbirth, severe multi-organ disease and life-long sequalae/disability

STI Atlas (external site)

 

Diagnosis

Diagnosis is usually made with a combination of patient reported symptoms, clinical examination findings, NAAT swab of lesion/s (external site) and syphilis serology. 

Point of care testing (only useful for people with no past history of syphilis) is available in some WA Aboriginal Community Controlled Health Services, hospitals and community health, remote area health and antenatal clinics. All syphilis point of care tests (positive or negative) must be confirmed by syphilis serology on a venous blood sample. 

If there is a clinical suspicion of primary syphilis but serology is negative, ensure a PCR swab for syphilis, herpes simplex virus (HSV) and, if indicated, mpox, has been done and repeat serology after 2 weeks following presumptive treatment.

Pregnant people should be offered syphilis testing at the first antenatal visit, 28 weeks and 36 weeks or at the time of any preterm birth. 

Interpreting syphilis serology

  • See Syphilis Decision Making Tool | ASHM Health (external site), noting that knowledge or previous testing +/- treatment enables accurate interpretation of syphilis serology
  • In patients who have a past history of syphilis (regardless of treatment), treponemal-specific antibodies e.g. TPHA, are usually positive for life
  • The RPR titre indicates disease activity and treatment response. It declines slowly in untreated patients but after treatment usually falls rapidly and often reverts to non-reactive
  • For help with interpreting syphilis serology contact your local public health unit or a specialist
Management

Penicillin is the drug of choice. The effectiveness of penicillin for treating syphilis has been well established and treponemes have not developed penicillin-resistance.

It is essential that syphilis serology, specifically the RPR, is repeated on the day of treatment so the response to treatment can be accurately assessed.

Benzathine benzylpenicillin (Bicillin L-A) is on the Emergency Drug Supply Schedule (Prescribers Bag) (external site).

If you have any difficulty obtaining benzathine benzylpenicillin for syphilis treatment, refer the patient urgently to a specialist sexual health clinic or contact your local public health unit for assistance to obtain this medication.

For additional information see Syphilis Decision Making Tool | ASHM (external site)

Syphilis stage/situation Antibiotic2,3 Important considerations
Early (<2 years duration) syphilis, includes primary, secondary and early latent1

Benzathine benzylpenicillin 2.4 MU (1.8 g) IMI, stat, given as 2 injections containing 1.2 MU (0.9 g) – preferred

OR

Doxycycline 100 mg orally twice a day for 14 days – seek specialist advice if considering this

Seek specialist advice if patient is a child

  • Perform a full STI check-up including HIV serology if not done as part of initial testing.
  • Jarisch-Herxheimer reaction is a common reaction to treatment in patients with primary and secondary syphilis. It occurs 6-12 hours after commencing treatment. Symptoms include fever, headache, malaise, rigors and joint pains which can be controlled with analgesics and rest. Inform patients of to the possibility of this reaction and reassure them that it is not dangerous.
  • 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 3 months (primary syphilis), 6 months (secondary syphilis), 12 months (early latent) or current partner/s (late latent) until the partners have been tested and treated if necessary
  • Contact tracing and presumptive treatment of partners of patient with primary or secondary syphilis where last contact was within 3 months (see contact tracing section for more information)
  • Provide patient information: Syphilis (HealthyWA)
  • Notify WA Health
  • It is a legal requirement to report all reasonable beliefs of child sexual abuse (external site) to the Department of Communities
Late latent syphilis (>2 years duration) or syphilis of unknown duration

Benzathine benzylpenicillin 2.4 MU (1.8 g) IMI, given as 2 injections containing 1.2 MU (0.9 g) weekly for 3 weeks4 – preferred

OR

Doxycycline 100 mg orally twice a day for 28 days – seek specialist advice if considering this

Seek specialist advice if patient is a child
HIV co-infection Discuss with a specialist
Syphilis in pregnancy

Treatment is the same as for non-pregnant patients

Doxycycline is contraindicated

Seek specialist advice if patient is allergic to penicillin as allergy testing is required, and if allergy is confirmed desensitisation to penicillin is required

See above and refer to Syphilis in Pregnancy Guidelines (external site) and contact your local public health unit

Jarisch-Herxheimer reaction may precipitate uterine contractions, preterm labour, and/or abnormal fetal heart rate tracings in pregnant women treated in the second half of pregnancy

Women with early syphilis (< 2 years duration or with an unknown duration of infection) and a pregnancy gestation of greater than 23 weeks who are able to be admitted to KEMH should be admitted for treatment and monitoring for 24 hours where practicable. For women residing remote to KEMH with a diagnosis of early syphilis (< 2years gestation or with an unknown duration of infection), the option of transfer to KEMH for treatment should be considered if the fetus is abnormal on ultrasound and gestation is greater than 23 weeks. For women residing in remote areas diagnosed with early syphilis, but with no known ultrasound abnormalities, it is preferable for women to be treated at the local hospital or clinic, or at a minimum to stay within an area of health care provision for 24 hours

Neurosyphilis (any stage), Tertiary syphilis Seek specialist advice, intravenous treatment required -
Congenital syphilis

Seek specialist advice

Refer to Child and Adolescent Health Service's guideline Syphilis: Investigation and management of the neonate born to a mother with syphilis (external site)

Syphilis testing at the booking, 28 and 36 week visits at a minimum is recommend to prevent congenital syphilis. 

Each case of congenital syphilis must be reviewed within 8 weeks of delivery by the local public health unit for the purpose of health system improvement and preventing future avoidable cases. See WA Guidelines for review of congenital syphilis cases. 

1. If any doubt about the length of infection, treat as late latent disease

2. For treatment of adults and 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. 

3. Seek specialist advice if considering doxycycline treatment because there is less evidence of effectiveness of non-penicillin regimens, and they must be regarded as inferior to penicillin. 

4. If the 2nd or 3rd dose is delayed by more than 3 days, it is recommended to restart the 3 week course

 

Contact tracing
  • Contact tracing (external site) is important to prevent re-infection and reduce transmission.
  • The diagnosing doctor is responsible for initiating and documenting a discussion about contact tracing.
  • Trace back according to sexual history and clinical stage of infection:
    • Primary syphilis: 3 months plus duration of symptoms or last negative test
    • Secondary syphilis: 6 months plus duration of symptoms or last negative test
    • Early latent: 12 months or most recent negative test
    • Late latent syphilis: Test current partner/s. If any doubt as to whether the patient has early latent or late latent syphilis, contact trace as for early latent syphilis.
  • Presumptively treat all sexual contacts from the last 3 months of patients with primary or secondary syphilis regardless of serology with benzathine benzylpenicillin 2.4 MU (1.8 g) IMI, Stat.
  • 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
  • repeat RPR to assess treatment response
  • confirm contact tracing has been undertaken or offer more contact tracing support, and
  • educate about condom use, contraception, HIV PrEP/PEP, Doxy PEP, safe injecting practices, consent, cervical screening and vaccinations for HAV, HBV, HPV and mpox as indicated.

Test of cure is recommended for all patients:

  • repeat RPR 3 monthly after completing treatment until a 4-fold (e.g. 1:16 or 1:4) drop is achieved
  • seek specialist advice if symptoms persist, RPR is rising or has not dropped 4-fold by 12 months

Consider doxycycline post-exposure prophylaxis (Doxy-PEP) in gay, bisexual and other men who have sex with men and transgender women who have recently had multiple STIs, are experiencing a period of heightened STI risk (e.g. attendance at a sex event, or holiday plans involving sexual activity with casual sexual partners), or have partner/s with a uterus (recognising the additional health risks posed by chlamydia, gonorrhoea and syphilis for people with a uterus). Refer to ASHM Doxy-PEP consensus statement (external site) (health professionals) and Doxy-PEP tool (external site) (health consumers).

Last reviewed: 19-09-2024