Syphilis, congenital
2026 Case Definition

Background

An infection of a stillbirth, neonate, or older child with T. pallidum contracted via transplacental transmission or, more rarely, exposure to genital lesions during birth. Congenital syphilis is commonly asymptomatic but may present with early or late signs and symptoms which are often non-specific.

Clinical Criteria

• A liveborn infant or child aged less than 2 years with any of the following signs or symptoms where there is not another more likely cause^*:
  • Rhinitis (i.e., copious nasal secretions, “syphilitic snuffles”)
  • Skin rash (e.g., maculopapular, consisting of small dark red-copper spots that is most severe on the hands and feet or vesicular rash – pemphigus syphiliticus); the skin rash can be associated with desquamation/sloughing
  • Condylomata lata
  • Pseudoparalysis of an extremity due to osteochondritis or periostitis
  • Nonimmune hydrops or edema; nephrotic syndrome
  • Conjugated or direct hyperbilirubinemia
  • Cholestatic jaundice or cholestasis
  • Hepatosplenomegaly
  • Other nonspecific signs/symptoms such as those listed below may provide supportive clinical evidence:
    • Lymphadenopathy
    • Fever
    • Mucocutaneous lesions
    • Pneumonia/pneumonitis
    • Hemolytic anemia or thrombocytopenia during the first 8 weeks after birth
    • Another clinical sign or symptom documented by a clinician to be consistent with a diagnosis of congenital syphilis

OR

• An older child (greater than or equal to 2 years of age) with any of the following signs or symptoms where there is not another more likely cause^*:
  • Interstitial keratitis
  • Nerve deafness
  • Anterior bowing of shins
  • Frontal bossing
  • Mulberry molars
  • Hutchinson teeth
  • Saddle nose
  • Rhagades
  • Clutton joints

^*Given that congenital syphilis is a multisystemic condition with varying presentations, this list is not exhaustive, and signs and symptoms of congenital syphilis may be nonspecific.

Other Fetal Death/Stillbirth Criteria

• A fetal death/stillbirth that occurs either:
  • at or after 20 weeks of gestation, OR
  • in which the fetus weighs greater than or equal to 350 grams.

Laboratory Criteria

Confirmatory Laboratory Evidence:

Meets at least one of the following criteria in an appropriate specimen^†:

• Direct detection of T. pallidum by darkfield microscopy in a specimen that was both not obtained from the oropharynx and not potentially contaminated by stool, OR
• Direct detection of T. pallidum by IHC staining in a specimen that was both not obtained from the oropharynx and not potentially contaminated by stool, OR
• Direct detection of T. pallidum by nucleic acid amplification test (e.g., PCR, LAMP) or a diagnostically equivalent molecular method in any specimen.

Presumptive Laboratory Evidence:

• A current (i.e., a test performed in the context of this index presentation) reactive blood-based nontreponemal antibody test (i.e., VDRL, RPR, point-of-care, or equivalent nontreponemal method) collected from an infant or child.

Supportive Laboratory/Radiographic Evidence:

Meets at least one of the following criteria in an infant or child, with no other identifiable causes for these abnormalities:

• In a lumbar puncture without visibly blood-contaminated cerebrospinal fluid (CSF)^‡, a reactive CSF VDRL test or an elevated CSF leukocyte^§ (white blood cell, WBC) count, OR
• A blood-based nontreponemal antibody test titer at least fourfold higher than the maternal blood-based nontreponemal antibody test titer in specimens collected during the immediate postnatal period (i.e., within 7 days), OR
• Evidence on radiographs of long bone abnormalities consistent with congenital syphilis.

Note: The categorical labels used here to stratify laboratory evidence are intended to support the standardization of case classifications for public health surveillance. The categorical labels should not be used to interpret the utility or validity of any laboratory test methodology.

^†An appropriate specimen is defined for each test type in the CDC Laboratory Recommendations for Syphilis Testing or equivalent guidance documents.

^‡For the purposes of the syphilis surveillance case definition, visibly blood-contaminated CSF is defined as a CSF red blood cell (RBC) count of greater than or equal to 500 RBCs/µL or, in the absence of an available CSF RBC count, CSF that is described as bloody in appearance in a medical record.

^§Suggested parameters for abnormal CSF WBC count may be found in the most recent CDC STI Treatment Guidelines or equivalent CDC clinical management guidelines. Whenever possible, the treating clinician should be consulted to interpret the CSF values for the specific patient.

Epidemiologic Linkage

• A stillborn infant, liveborn infant, or child born to a woman with untreated or inadequately^** treated syphilis at delivery.

^** Inadequate treatment for a non-pregnant woman is any treatment given that differs from the recommended or alternative treatments listed in the CDC STI Treatment Guidelines or equivalent CDC clinical management guidelines. Inadequate treatment in pregnancy is anything other than completion of a recommended regimen, in accordance with the CDC STI Treatment Guidelines or equivalent CDC clinical management guidelines, initiated 30 or more days before delivery.

Vital Records Criteria

• A fetal death in which syphilis is specified on the Report of Fetal Death as the cause of, or a condition contributing to, fetal death.

Probable

• A liveborn infant or child who meets epidemiologic linkage criteria,

OR

• A liveborn infant or child who meets presumptive laboratory evidence AND the suspected or most likely source of exposure is in utero AND either:
  • Meets clinical criteria, OR
  • Meets supportive laboratory/radiographic evidence,

OR

• A fetal death or stillbirth that meets other fetal death/stillbirth criteria AND either:
  • Meets epidemiologic linkage criteria, OR
  • Meets vital records criteria.

Confirmed

• A liveborn infant or child who meets confirmatory laboratory evidence AND the suspected or most likely source of exposure is in utero, OR
• A fetal death or stillbirth that meets other fetal death/stillbirth criteria AND meets confirmatory laboratory evidence.

• Syphilis (Treponema pallidum) | 2026 Case Definition