Congenital Syphilis
Introduction to Congenital Syphilis
Congenital syphilis is a severe, potentially life-threatening infection that occurs when the spirochete Treponema pallidum is transmitted from a mother to her fetus during pregnancy or at birth. It remains a significant global health concern, particularly in resource-limited settings.
Key points:
- Caused by vertical transmission of Treponema pallidum
- Can occur at any stage of pregnancy, but risk is highest in early maternal infection
- Can lead to severe multisystem complications, stillbirth, or neonatal death
- Preventable with timely diagnosis and treatment of maternal syphilis
- Incidence varies globally, with higher rates in low- and middle-income countries
Pathophysiology of Congenital Syphilis
The pathophysiology of congenital syphilis involves several key processes:
- Maternal infection:
- Primary infection: local inoculation and replication of T. pallidum
- Secondary infection: hematogenous and lymphatic dissemination
- Latent and tertiary stages: persistent infection with periodic bacteremia
- Transplacental transmission:
- Occurs as early as 9-10 weeks gestation
- Risk increases with gestational age
- Higher transmission rates in early maternal infection
- Fetal infection:
- Widespread spirochetemia in the fetus
- Direct invasion of fetal organs and tissues
- Inflammatory response leading to tissue damage
- Placental effects:
- Villitis and vascular changes
- Reduced placental blood flow
- Potential for fetal growth restriction
- Immune response:
- Fetal production of IgM antibodies
- Transfer of maternal IgG antibodies
- Development of immune complexes
The interplay of these factors determines the severity and manifestations of congenital syphilis, which can range from asymptomatic infection to severe multisystem disease.
Clinical Manifestations of Congenital Syphilis
Congenital syphilis can present with a wide spectrum of clinical manifestations, which are often classified as early (appearing in the first 2 years of life) or late (appearing after 2 years of age):
- Early congenital syphilis:
- Prematurity and low birth weight
- Hepatomegaly and splenomegaly
- Jaundice and unconjugated hyperbilirubinemia
- Skin manifestations:
- Maculopapular rash
- Desquamation, especially on palms and soles
- Petechiae and purpura
- Mucous patches
- Condyloma lata
- Snuffles (rhinitis with blood-tinged discharge)
- Lymphadenopathy
- Osteochondritis and pseudoparalysis (Parrot's pseudoparalysis)
- Pneumonia alba
- Nephrotic syndrome
- Neurological manifestations:
- Meningitis
- Hydrocephalus
- Cranial nerve palsies
- Hematological abnormalities:
- Anemia
- Thrombocytopenia
- Leukocytosis or leukopenia
- Late congenital syphilis:
- Hutchinson's triad:
- Interstitial keratitis
- Hutchinson's teeth (peg-shaped, notched incisors)
- Eighth nerve deafness
- Skeletal abnormalities:
- Frontal bossing
- Saddle nose
- Saber shins
- Clutton's joints (symmetric, painless synovitis of knees)
- Neurological sequelae:
- Intellectual disability
- Seizures
- Juvenile general paresis
- Tabes dorsalis
- Cardiovascular syphilis:
- Aortic regurgitation
- Coronary ostial stenosis
- Hutchinson's triad:
The clinical presentation can be highly variable, and some infants may be asymptomatic at birth but develop symptoms later. A high index of suspicion is crucial for early diagnosis and treatment.
Diagnosis of Congenital Syphilis
Diagnosis of congenital syphilis involves a combination of maternal history, clinical examination, and laboratory investigations:
- Maternal screening:
- Serological testing during pregnancy (ideally in the first trimester and third trimester)
- Nontreponemal tests: RPR (Rapid Plasma Reagin) or VDRL (Venereal Disease Research Laboratory)
- Treponemal tests: FTA-ABS (Fluorescent Treponemal Antibody Absorption) or TPPA (Treponema pallidum Particle Agglutination)
- Neonatal evaluation:
- Physical examination for signs of congenital syphilis
- Serological testing:
- Nontreponemal test (RPR or VDRL)
- Comparison of infant's titer with maternal titer
- Treponemal test (if nontreponemal test is reactive)
- Cerebrospinal fluid (CSF) analysis:
- Cell count and protein
- VDRL test on CSF
- Complete blood count
- Liver function tests
- Direct detection methods:
- Dark-field microscopy of lesions or body fluids
- PCR for T. pallidum DNA
- Imaging studies:
- Long bone radiographs
- Chest X-ray
- Cranial ultrasound
- Other investigations:
- Ophthalmologic examination
- Auditory brainstem response
Diagnosis can be challenging due to the transplacental transfer of maternal antibodies. The CDC provides specific criteria for the diagnosis and evaluation of congenital syphilis, which should be followed for accurate case classification and management.
Management of Congenital Syphilis
Management of congenital syphilis involves prompt treatment of the infant and appropriate follow-up:
- Antibiotic therapy:
- Aqueous crystalline penicillin G:
- Preferred regimen: 50,000 units/kg IV every 12 hours (first 7 days of life) or every 8 hours (after 7 days of life)
- Duration: 10 days
- Alternative: Procaine penicillin G, 50,000 units/kg IM daily for 10 days
- For penicillin-allergic patients: Desensitization and treatment with penicillin is recommended
- Aqueous crystalline penicillin G:
- Supportive care:
- Management of specific complications (e.g., respiratory support, treatment of seizures)
- Fluid and electrolyte management
- Nutritional support
- Monitoring:
- Serial nontreponemal antibody titers (at 3, 6, and 12 months)
- CSF examination (if initial CSF was abnormal)
- Repeat long bone radiographs (if initially abnormal)
- Management of specific manifestations:
- Ophthalmologic treatment for interstitial keratitis
- Hearing aids or cochlear implants for sensorineural hearing loss
- Neurodevelopmental follow-up and early intervention
- Treatment of mothers and partners:
- Appropriate antibiotic therapy based on stage of syphilis
- Partner notification and treatment
- Long-term follow-up:
- Regular developmental assessments
- Monitoring for late manifestations
- Annual ophthalmologic and audiologic examinations
Treatment should be initiated promptly in all infants with confirmed or probable congenital syphilis. Close follow-up is essential to ensure adequate response to therapy and to monitor for long-term sequelae.
Prevention of Congenital Syphilis
Prevention of congenital syphilis primarily focuses on screening and treating pregnant women and their partners:
- Prenatal screening:
- Universal serological screening at the first prenatal visit
- Repeat screening at 28-32 weeks and at delivery in high-risk populations
- Treatment of maternal syphilis:
- Penicillin G is the only known effective antimicrobial for preventing maternal transmission
- Treatment regimen depends on the stage of syphilis and gestational age
- For penicillin-allergic patients, desensitization is recommended
- Partner management:
- Identification and treatment of sexual partners
- Counseling on safe sexual practices
- Public health interventions:
- Health education and awareness campaigns
- Accessible and affordable testing and treatment services
- Integration of syphilis screening with other antenatal care services
- Surveillance and reporting:
- Mandatory reporting of syphilis cases to public health authorities
- Monitoring of congenital syphilis rates to assess prevention efforts
- Post-exposure prophylaxis:
- Treatment of exposed infants based on maternal treatment status and infant evaluation
- Research and development:
- Improved diagnostic tests, especially point-of-care tests
- Vaccine development (currently in early stages)
Effective prevention requires a comprehensive approach involving healthcare providers, public health systems, and community engagement. The World Health Organization (WHO) has set targets for the elimination of mother-to-child transmission of syphilis, emphasizing the importance of integrating syphilis prevention with other maternal and child health programs.
Congenital Syphilis
- What is the causative agent of congenital syphilis?
Treponema pallidum - How is congenital syphilis transmitted?
Transplacental transmission from an infected mother to the fetus - What percentage of untreated maternal syphilis cases result in congenital syphilis?
Approximately 40% - Which trimester of pregnancy carries the highest risk of fetal infection?
First and second trimesters - What is the most common symptom of early congenital syphilis?
Rhinitis ("snuffles") - What type of rash is characteristic of congenital syphilis?
Copper-colored, maculopapular rash on palms and soles - What is Hutchinson's triad in congenital syphilis?
Interstitial keratitis, Hutchinson's teeth, and eighth cranial nerve deafness - Which long bone abnormality is commonly seen in congenital syphilis?
Osteochondritis at the metaphysis - What is the preferred diagnostic test for congenital syphilis?
Darkfield microscopy of lesion exudate or tissue - Which serologic test is most specific for syphilis?
Fluorescent treponemal antibody absorption (FTA-ABS) test - What is the drug of choice for treating congenital syphilis?
Penicillin G - How long should infants with congenital syphilis be treated with parenteral penicillin?
10 days - What is the appropriate follow-up interval for serologic testing in treated infants?
Every 3 months until nonreactive or 4-fold decline in titer - Which organ is most commonly affected in early congenital syphilis?
Liver (hepatomegaly) - What is the term for syphilitic inflammation of the nasal mucosa and cartilage?
Syphilitic rhinitis or "snuffles" - What is the most common radiographic finding in congenital syphilis?
Periostitis - How does congenital syphilis affect the central nervous system?
It can cause meningitis, hydrocephalus, and cranial nerve palsies - What is the significance of a positive VDRL test in cerebrospinal fluid?
It indicates neurosyphilis - Which hematologic abnormality is common in congenital syphilis?
Anemia - What is Parrot's pseudoparalysis in congenital syphilis?
Painful swelling of long bones causing decreased movement of extremities - How does congenital syphilis affect the teeth?
It causes Hutchinson's teeth (notched incisors) and mulberry molars - What is the name for the characteristic frontal bossing seen in congenital syphilis?
Olympian brow - Which eye finding is associated with late congenital syphilis?
Interstitial keratitis - What is the term for linear cracks around the mouth in congenital syphilis?
Rhagades - How does congenital syphilis affect the spleen?
It causes splenomegaly - What is the significance of a positive RPR test in a newborn?
It may indicate passive transfer of maternal antibodies or active infection - How long can IgG antibodies from the mother persist in an uninfected infant?
Up to 15 months - What is the appropriate treatment for infants born to mothers adequately treated for syphilis during pregnancy?
A single dose of benzathine penicillin G - Which cranial nerve is most commonly affected in congenital syphilis?
Eighth cranial nerve (vestibulocochlear) - What is the prognosis for infants treated early for congenital syphilis?
Generally good, with most symptoms resolving within weeks to months
