Syphilis (congenital) case definition

This document contains the case definition for Congenital syphilis which is nationally notifiable within Australia. This definition should be used to determine whether a case should be notified.

Page last updated: 01 July 2015

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Inclusion of a syphilis-related stillbirth where this was previously a note for the ‘Laboratory definitive evidence’ section.

Laboratory Definitive Evidence

Inclusion of detection of Treponema pallidum specific IgM in the child.

Inclusion of a nucleic acid amplification (NAA) test as a means of direct demonstration of Treponema pallidum.

Removal of the serological criterion for proof of treatment in point 4. This is also reflected in the last sentence of the ‘Clinical evidence’ section.

CDWG May 2015 CDNA June 2015 1 July 2015


Confirmed Case: ‘Laboratory Suggestive and Clinical evidence’ moved to define a Probable Case.

Probable Case: Structure and content of ‘Probable Case’ section amended to be consistent with Case Definition style guide and comprise Laboratory Suggestive and Clinical evidence.

Lab Definitive evidence: Extensive rework of section including: removal of specific reference to treponemal IgM assays; inclusion of requirement that NAT and other tests be corroborated; broadening of the specimen sites which might get tested; adding criteria allowing for the persistence of antibody in infants to count as definitive.

Lab Suggestive evidence: Reworking of section including: removal of specific reference to IgM assays; removing NAT from a non-sterile site (now definitive evidence if corroborated); adding seropositivity in either child or mother.

Clinical Evidence: Structure and content of ‘Clinical Evidence’ section amended to be consistent with Case Definition style guide. ‘Asymptomatic infection’, ‘Foetal death in utero’ and ‘Stillbirth in a foetus greater than 20 weeks gestation’ removed from criteria, but accounted for in the notes; details of clinical evidence also removed; rewording of the clause defining inadequate maternal treatment; moving laboratory evidence into appropriate sections.

CDWG O-O-S January 2010 CDNA 29 September 2010 1 January 2011
1.0 Initial case definition (2004).      
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Both confirmed cases and probable cases should be notified,including syphilis-related stiilbirth.1

Confirmed case

A confirmed case requires laboratory definitive evidence.

Laboratory definitive evidence

Mother and child both seropositive by a treponemal specific test2


One or more of the following:

Direct demonstration of Treponema pallidum by any of the following: nucleic acid amplification (NAA) test, dark field microscopy, fluorescent antibody or silver stain - in specimens from lesions, nasal discharge, placenta, umbilical cord, cerebrospinal fluid (CSF), amniotic fluid or autopsy material


Detection of Treponema pallidum specific IgM in the child


The child’s serum non-treponemal3 serology titre at birth is at least fourfold greater than the mother's titre.

Probable case

A probable case requires laboratory suggestive evidence AND clinical evidence.

Laboratory suggestive evidence

Direct demonstration of Treponema pallidum as described under laboratory definitive evidence (above), but without serological confirmation in the child.


Child seropositive on non-treponemal testing in the absence of IgM testing


A reactive CSF non-treponemal test (VDRL or RPR) in a child.


A child who remains seropositive by a treponemal specific test at 15 months of age, which is confirmed either by another, different reactive treponemal specific test or a reactive non-treponemal test, in the absence of post-natal exposure to Treponema pallidum , including the non-venereal subspecies Treponema pallidum subsp. pertenue (Yaws) or subsp. endemicum (Bejel, endemic syphilis).

Clinical evidence

1. Any evidence of congenital syphilis on physical examination


2. Any evidence of congenital syphilis on radiographs of long bones


3. An elevated CSF cell count or protein (without other cause)


4. The mother is seropositive in the perinatal period AND has no documented evidence of adequate treatment4.

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1. A stillbirth where the foetal death has occurred after a 20 week gestation or in a foetus which weighs greater than 500g should be counted as clinical evidence towards a case where laboratory suggestive or definitive evidence exists.

2. Treponemal specific tests are:

Treponema pallidum immunoassays, Treponema pallidum haemagglutination assay (TPHA), Treponema pallidum particle agglutination assay (TPPA), Fluorescent Treponemal Antibody Absorption (FTA-Abs) and various IgM assays including 19S-IgM antibody test, or IgM immunoassay. IgM assays should not be used for screening purposes.

Treponema pallidum-specific rapid immunochromatography (ICT) assays for use as point-of-care tests are now becoming available, but their performance has not yet been fully established. Positive ICT results should be confirmed with a second treponemal specific assay.

3. Non-treponemal tests are the agglutination assays Rapid Plasma Reagin (RPR) and Venereal Disease Research Laboratory (VDRL). Any positive sera should be tested by serial dilution to provide an end-titre. Non-treponemal tests may be used to monitor efficacy of treatment. Mother and child sera should be collected contemporaneously and tested in parallel and cord blood should not be used for the investigation of congenital syphilis.

4. Treatment is considered adequate if

  • a stage-appropriate penicillin-containing regimen was used 30 days or more prior to delivery AND
  • all antenatal and delivery pathology investigations were performed and results verified AND
  • there is no evidence of reinfection.

4.1 Treatment with macrolides alone during pregnancy in penicillin-allergic women is no longer regarded as adequate therapy as resistance to macrolides in T. pallidum is increasingly common and may arise during therapy.

4.2 Although the risk of congenital syphilis is much higher in early-stage disease, in the presence of untreated syphilis the birth of an unaffected child does not guarantee that subsequent children will not be affected.

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