Syphilis (Treponema pallidum)
Syphilis is caused by the Gram-negative spirochete Treponema pallidum. Trans-placental infection can occur at any stage of pregnancy, during any stage of maternal disease.
Syphilis is caused by the Gram-negative spirochete Treponema pallidum. Trans-placental infection can occur at any stage of pregnancy, during any stage of maternal disease.
See NZSHS guidelines on Syphilis in Pregnancy for detailed information on the approach to diagnosis, treatment and follow-up (Pages 20-26 and Table 3, page 23.)
Indications
Evaluation of Newborn for syphilis is indicated if:
Maternal syphilis not treated, inadequately treated or treatment inadequately documented
Maternal syphilis has been treated but with inadequate follow up OR without demonstration of expected 4-fold drop in non-treponemal antibody titre (RPR titre)
Maternal syphilis in pregnancy treated with a non-penicillin regimen (e.g., erythromycin or ceftriaxone)
Maternal syphilis treatment completed <30 days prior to birth
Final RPR titre >1:4
Or if any of the following clinical features are present:
Osteochondritis/periostitis
Snuffles, haemorrhagic rhinitis
Condylomata lata
Bullous lesions
Plantar/palmar rash
Mucous patches
Unexplained enlarged placenta
Nephrotic syndrome (rare, usually at 2-3 months of age)
Nonspecific signs of congenital infection for which syphilis testing should be considered include:
Hepatomegaly +/-splenomegaly (NB splenomegaly alone does not occur with congenital syphilis but can with congenital CMV)
Jaundice
Non-immune hydrops fetalis (NB also check for parvovirus)
Generalised lymphadenopathy
CNS signs, elevated cell count or protein in CSF
Haemolytic anaemia, DIC, thrombocytopenia
Pneumonitis
IUGR; failure to thrive
Initial investigations
Full clinical examination (rash, mucosal lesions, hepatomegaly, nasal discharge, bony tenderness, eye lesions)
Infant blood: syphilis serology (minimum 1mL, plain red tube)
Maternal blood: syphilis serology (paired in time with infant and processed at the same lab to allow for direct comparison of RPR)
NB: Testing of infant serum alone is not adequate for screening because these tests may be non-reactive when mother is positive. Mother's serology must be performed and reviewed in all suspected cases.
Further investigations may include the following depending on clinical situation and initial investigations:
Placenta histopathology and syphilis (T. pallidum) PCR
Syphilis (T. pallidum) PCR from lesions and/or nasal discharge if present. Discuss with microbiology lab first, use flocked viral swab .
Infant blood: Full blood count, LFTs, urea, creatinine, electrolytes
Infant CSF: Request VDRL, cell count and differential, protein and glucose. Discuss with paediatric I.D. first – the need for this will depend on the level of risk of infection and timely availability of serology results
Long bone X-Rays (osteochondritis and periostitis)
Ophthalmologic examination (interstitial keratitis)
Formal audiologic examination (sensorineural hearing loss)
Chest X-ray (cardiomegaly)
Neuroimaging
Treatment
Symptomatic infants require treatment as soon as possible after investigations are complete, with a 10-day course of Benzylpenicillin (dosing as per NZ Formulary/ NZSHS syphilis in pregnancy guideline.
All cases of congenital syphilis (confirmed and probable as per ESR case definition) must be notified to public health by treating paediatric or neonatal teams. This can be done using the ESR case questionnaire.
Paediatricians/neonatologists are also asked to notify cases to NZPSU for surveillance.
Isolation
Gloves should be worn for handling all babies with suspected congenital syphilis.
Moist open lesions of skin and mucous membranes, secretions and possibly blood are contagious until 24 hours of penicillin treatment has been completed.
Follow-up
Discuss with Paediatric Infectious Disease Team for treatment advice and follow-up.
For proven/highly probable or asymptomatic possible syphilis Paediatric review is indicated at 6 weeks, 3 months, 5-6 months and 12-18 months of life with repeat RPR.
Follow-up may still be indicated in situations where an infant is at risk but “congenital syphilis is less likely.” See Table 3, NZSHS Syphilis in pregnancy guideline.
For outpatient referrals in the Starship region:
Send an electronic referral to Paediatric Infectious Diseases and ensure that the mother's full information is included in the referral: NHI, maternal serology results and treatment details
Give family a laboratory form for repeat blood tests prior to discharge and instruct them to complete these the week prior to first clinic appointment
Cases outside the Starship region should be referred to local General Paediatric services for follow-up.