Syphilis

• Increasing incidence in Aotearoa New Zealand in recent years particularly in Auckland and other North Island District Health Boards
• Most syphilis diagnosed in Aotearoa New Zealand is contracted within this country, however syphilis is also commonly diagnosed in migrants from countries with a high prevalence of syphilis, e.g. Eastern Europe, Southeast Asia, China, South America, Africa, Pacific Islands (especially Fiji)
• Transmission is through
  • Intimate contact with mucocutaneous skin, including vaginal, penile, anal and oral sex. Condoms are not fully protective
  • From mother to baby (mainly transplacental)
• Syphilis is most commonly diagnosed in
  • Men who have sex with men (MSM), however one third of notified cases are currently occurring in heterosexual people
  • Sexual contacts of people with syphilis
• Infectious syphilis is a notifiable condition
• Since 2016, there has been a trend to more cases of congenital syphilis, reflecting the increased incidence in women of reproductive age. Māori and Pacific Peoples are disproportionately affected
• Syphilis in pregnancy carries a very high risk of adverse pregnancy outcomes, and requires urgent specialist management. A New Zealand Sexual Health Society (NZSHS) Syphilis in Pregnancy guideline is available
• Syphilis serology can be difficult to interpret, with potentially significant adverse consequences for the patient if incorrectly managed. Seek specialist advice for assistance in interpreting serology results if unsure

Clinically, the disease has 3 stages; however approximately 50% of people will have no symptoms and will only be diagnosed by serological testing (see latent syphilis below).  Neurosyphilis can occur at any stage of syphilis.

See STI Atlas for images.

• Patient with possible signs or symptoms of syphilis:
  • Genital or anal ulcers
  • Persisting oral lesions in people at risk for sexually transmitted infections (STIs)
  • Sexually active people with any genital symptoms or generalised rash
  • Any rash affecting the palms of the hands or soles of the feet, or that is persistent or unexplained
  • Pyrexia of unknown origin, unexplained persistent lymphadenopathy, unexplained liver function disturbance, alopecia
  • Neurological signs and symptoms including aseptic meningitis, cranial nerve palsies, sudden onset unilateral sensorineural deafness and dementia
  • Ocular symptoms, e.g. uveitis, optic neuritis
• Sexual contacts of people with syphilis
• MSM (at least annually, but ideally with every sexual health check)
• In pregnancy as part of routine antenatal screening. Consider rescreening in later pregnancy. For more detailed guidance, see NZSHS Syphilis in Pregnancy guideline and NZSHS position statement on re-testing pregnant women for syphilis infection or re-infection
• Routine immigration testing
• When doing a routine sexual health check

Note: If patient is a contact of a person with syphilis they will usually need empiric treatment at time of testing. Discuss with sexual health specialist. If patient is asymptomatic and not a syphilis contact, but is concerned about a specific recent sexual event, it is recommended to do a baseline test at time of presentation and do a repeat test 3 months from the time of last sexual intercourse

Symptomatic people and contacts of syphilis should be examined

Testing for syphilis should occur as part of a complete sexual health check

• Diagnosis is by a combination of serology, history and clinical assessment
• Note seroconversion may take up to 3 months after exposure to infection
• If clinical suspicion of syphilis, discuss with a sexual health specialist

EIA – Enzyme immunoassay

TPPA - Treponema pallidum Particle Agglutination Assay

TPHA - Treponema pallidum Hemagglutination Assay

RPR – Rapid plasma reagin

PCR - Polymerase chain reaction

Syphilis serology can be difficult to interpret, with potentially significant adverse consequences for the patient if incorrectly managed. Seek specialist advice for assistance in interpreting serology results if unsure

• In patients with prior treated syphilis, the EIA and TPPA/TPHA tests usually remain reactive for life, although seroreversion can rarely occur
• In approximately 25% of cases, the RPR will become non-reactive (seroreversal) after a number of years even without treatment. Therefore all people without a documented history of treatment should be treated even if they have a non-reactive RPR test
• RPR titres usually drop after treatment but may not change significantly in low-titre infections or in cases of late latent syphilis (serofast)
• A 4-fold (2 dilution) increase in RPR titre after treatment is indicative of re-infection

• Treatment should be given by, or following discussion with, a sexual health specialist
• Patients should have syphilis serology repeated on the day treatment is commenced to provide an accurate baseline for monitoring
• The penicillin formulation used for treatment must be long-acting, i.e. Bicillin L-A (benzathine benzylpenicillin tetrahydrate)

Principle treatment option

•  Intramuscular benzathine penicillin may be painful due to volume and viscosity.  The Bicillin-L-A prefilled syringe should be warmed to room temperature before use. 0.25 mL of lidocaine 2% may be added to each prefilled Bicillin L-A syringe to reduce injection pain
• Jarisch-Herxheimer reaction is a common reaction to treatment in patients with primary and secondary syphilis. It occurs 6-12 hours after commencing treatment, and is an unpleasant reaction of varying severity with fever, headache, malaise, rigors and joint pains, lasting for several hours. Symptoms are controlled with analgesics and rest. Patients should be alerted to the possibility of this reaction and reassured accordingly

 Special Situations

• Advise to abstain from sex for 1 week from the start of treatment and until 1 week after sexual contact/s have been treated
• Initiate contact tracing – see below for details
• Children of women newly diagnosed with syphilis should be tested, if it is possible that the index case acquired syphilis before or during pregnancy
• Infectious syphilis is a notifiable condition
• Consider HIV pre-exposure prophylaxis (PrEP) if infectious syphilis is diagnosed in a male or transgender person who has anal sex with men

• Over 20% risk of transmission per act of unprotected intercourse (for early syphilis)
• Contact tracing is important to prevent re-infection and reduce transmission
• Trace according to sexual history and clinical stage of infection:
  • Primary syphilis: 3 months plus duration of symptoms
  • Secondary syphilis: 6 months plus duration of symptoms
  • Early latent syphilis: 12 months
  • Syphilis of unknown duration where RPR ≥ 1:32: 12 months
  • Late latent syphilis: serological evaluation of current or last sexual contact and serological evaluation of children if index case is female

• Most patients choose to tell contacts themselves; giving written information can be helpful
• Notifying all contacts may not be possible e.g. if there is insufficient information or a threat of violence

Management of sexual contacts

• Contacts should have a full sexual health check, including general examination for signs of syphilis, and should be discussed with a sexual health specialist
• It can take up to 90 days for syphilis serology to become positive after infection, therefore contacts of infectious syphilis from within this time period should be treated empirically regardless of test results.  Repeat serology is recommended in 3 months for those who decline empiric treatment
• Advise contacts to abstain from sex or use condoms until results are available, and for one week from the start of treatment
• If contacts test positive for an STI refer to specific guideline

Referral to or discussion with a sexual health specialist is recommended for:

• All patients with newly reactive syphilis serology
• Concern for possible re-infection or relapse
• Assistance in interpreting serology results if unsure
• Contacts of people with infectious syphilis
• Syphilis in pregnancy

Syphilis serology can be difficult to interpret, with potentially significant adverse consequences for the patient if incorrectly managed. Seek specialist advice if unsure.

• 100% have had follow up serology tests by 6 months

Just the facts

Healthy Sex