Congenital Varicella Zoster Infections
Introduction to Congenital Varicella Zoster Infections
Congenital Varicella Zoster Virus (VZV) infection, also known as congenital varicella syndrome (CVS), occurs when a pregnant woman contracts primary VZV infection (chickenpox) and transmits the virus to her fetus. This rare but serious condition can lead to significant morbidity and mortality in affected infants.
- VZV is a DNA virus of the Herpesviridae family
- Incidence of CVS: Approximately 1-2% when maternal infection occurs in the first 20 weeks of gestation
- Risk is highest when maternal infection occurs between 13-20 weeks gestation
Understanding the pathophysiology, clinical presentation, and management of congenital varicella is crucial for healthcare providers to optimize outcomes for affected infants and provide appropriate counseling to pregnant women.
Transmission of Congenital Varicella Zoster
The risk and consequences of vertical transmission of VZV depend on the timing of maternal infection during pregnancy:
Timing of Maternal Infection
- First trimester (0-12 weeks):
- Low risk of transmission
- Potential for severe embryopathy
- Second trimester (13-28 weeks):
- Highest risk of congenital varicella syndrome
- Peak risk between 13-20 weeks
- Third trimester (>28 weeks):
- Lower risk of congenital syndrome
- Increased risk of neonatal varicella if infection occurs near term
Mechanisms of Transmission
- Transplacental: Primary route for congenital infection
- Ascending infection: Rare, but possible
- Perinatal: Can occur if maternal infection is near delivery date
Risk Factors
- Maternal primary VZV infection during pregnancy
- Lack of maternal immunity to VZV
- Immunocompromised pregnant women
Clinical Manifestations of Congenital Varicella Zoster
The clinical presentation of congenital varicella can vary widely, ranging from asymptomatic infection to severe multisystem involvement:
Congenital Varicella Syndrome (CVS)
Classical features include:
- Cutaneous manifestations:
- Cicatricial skin lesions in a dermatomal distribution
- Hypopigmented or hyperpigmented scars
- Neurological abnormalities:
- Microcephaly
- Cortical atrophy
- Seizures
- Intellectual disability
- Ocular defects:
- Chorioretinitis
- Microphthalmia
- Cataracts
- Optic atrophy
- Limb abnormalities:
- Hypoplasia of limbs
- Muscular atrophy
- Joint contractures
- Other manifestations:
- Intrauterine growth restriction
- Gastrointestinal abnormalities
- Cardiovascular defects
Neonatal Varicella
Occurs when maternal infection is near term:
- Mild disease: If maternal infection is >5 days before delivery
- Severe disease: If maternal infection is within 5 days before to 2 days after delivery
- Clinical features:
- Vesicular rash
- Pneumonia
- Hepatitis
- Encephalitis
Long-term Complications
- Developmental delays
- Learning disabilities
- Visual impairment
- Motor deficits
- Recurrent zoster infections
Diagnosis of Congenital Varicella Zoster
Diagnosing congenital varicella requires a combination of clinical assessment, maternal history, and laboratory investigations:
Maternal Diagnosis
- Clinical presentation of chickenpox during pregnancy
- Serological testing:
- VZV-specific IgM antibodies
- Significant rise in VZV IgG antibodies
- PCR detection of VZV DNA in vesicular fluid or blood
Prenatal Diagnosis
- Ultrasonography: May reveal fetal abnormalities consistent with CVS
- Amniocentesis: PCR detection of VZV DNA in amniotic fluid
- Fetal blood sampling: Rarely performed, can detect VZV DNA or antibodies
Neonatal Diagnosis
- Clinical examination for characteristic features of CVS
- Laboratory investigations:
- PCR detection of VZV DNA in blood, CSF, or skin lesions
- Serological testing for VZV-specific IgM antibodies
- Imaging studies:
- Brain MRI or CT to assess neurological involvement
- Ophthalmological examination
- Skeletal radiographs
Differential Diagnosis
Consider other congenital infections and syndromes, including:
- Other TORCH infections (Toxoplasmosis, Rubella, CMV, Herpes simplex)
- Congenital Zika syndrome
- Fetal alcohol syndrome
- Genetic disorders affecting limb development
Management of Congenital Varicella Zoster
Management of congenital varicella involves prevention, treatment of maternal infection, and care of affected infants:
Prevention
- Vaccination: Recommended for non-immune women before pregnancy
- Avoid exposure: Pregnant women should avoid contact with individuals with active varicella
- Post-exposure prophylaxis:
- Varicella-Zoster Immunoglobulin (VZIG) within 96 hours of exposure for susceptible pregnant women
- Acyclovir may be considered if VZIG is unavailable
Management of Maternal Infection
- Antiviral therapy: Acyclovir or valacyclovir for pregnant women with varicella
- Supportive care: Symptomatic treatment, hydration
- Fetal monitoring: Regular ultrasound examinations
Management of Affected Infants
- Neonatal varicella:
- VZIG administration immediately after birth
- Intravenous acyclovir for 7-10 days
- Congenital Varicella Syndrome:
- Multidisciplinary approach involving neonatologists, neurologists, ophthalmologists, and other specialists
- Symptomatic treatment of specific manifestations
- Early intervention programs for developmental support
- Long-term follow-up:
- Regular developmental assessments
- Ophthalmological examinations
- Neurological evaluations
- Physical and occupational therapy as needed
Counseling and Support
- Genetic counseling for future pregnancies
- Psychosocial support for families
- Education about potential long-term complications and care needs
Future Directions
- Development of more effective prenatal diagnostic techniques
- Research on potential in utero treatments
- Long-term outcome studies of infants with congenital varicella
Congenital varicella zoster infections can have significant implications for fetal and neonatal health, emphasizing the importance of prevention, early diagnosis, and appropriate management strategies. Healthcare providers play a crucial role in educating, screening, and providing comprehensive care to minimize the impact of these infections on maternal and child health.
Congenital Varicella Zoster Infections
- Q: What causes congenital varicella syndrome? A: Maternal varicella-zoster virus (VZV) infection during pregnancy
- Q: During which trimester of pregnancy is the risk of congenital varicella syndrome highest? A: First and early second trimester (before 20 weeks gestation)
- Q: What is the approximate risk of congenital varicella syndrome if maternal infection occurs before 20 weeks gestation? A: 0.4-2%
- Q: What are the classic triad of symptoms in congenital varicella syndrome? A: Skin lesions, neurological defects, and eye abnormalities
- Q: What type of skin lesions are characteristic of congenital varicella syndrome? A: Cicatricial skin lesions in a dermatomal distribution
- Q: What neurological abnormalities may be seen in congenital varicella syndrome? A: Microcephaly, cortical atrophy, seizures, and intellectual disability
- Q: What ocular abnormalities are associated with congenital varicella syndrome? A: Chorioretinitis, microphthalmia, and cataracts
- Q: What limb abnormalities may occur in congenital varicella syndrome? A: Hypoplasia of limbs, especially fingers and toes
- Q: How is congenital varicella syndrome diagnosed prenatally? A: Through maternal history, ultrasound findings, and amniocentesis for VZV PCR
- Q: What is the mortality rate for infants with congenital varicella syndrome? A: Approximately 30% in the first few months of life
- Q: How can congenital varicella syndrome be prevented? A: Vaccination of women of childbearing age before pregnancy
- Q: What is the recommended management for VZV-seronegative pregnant women exposed to varicella? A: Administration of varicella-zoster immunoglobulin (VZIG) within 96 hours of exposure
- Q: Can the varicella vaccine be given during pregnancy? A: No, it is contraindicated during pregnancy as it contains live attenuated virus
- Q: What is neonatal varicella, and how does it differ from congenital varicella syndrome? A: Neonatal varicella occurs when maternal infection is near term, resulting in chickenpox in the newborn
- Q: What is the risk period for severe neonatal varicella infection? A: Maternal infection occurring from 5 days before to 2 days after delivery
- Q: How is neonatal varicella treated? A: With intravenous acyclovir and supportive care
- Q: What long-term complications may occur in survivors of congenital varicella syndrome? A: Developmental delays, learning disabilities, and visual impairment
- Q: How does maternal immunity to varicella affect the risk of congenital infection? A: Maternal immunity significantly reduces the risk of congenital varicella syndrome
- Q: What is the role of PCR testing in diagnosing congenital varicella syndrome? A: It can detect VZV DNA in amniotic fluid or fetal blood
- Q: How does congenital varicella syndrome affect the cardiovascular system? A: It may cause ventricular septal defects and other cardiac abnormalities
- Q: What gastrointestinal abnormalities may be associated with congenital varicella syndrome? A: Gastroesophageal reflux, poor feeding, and failure to thrive
- Q: How does congenital varicella syndrome affect the skeletal system? A: It may cause bone and muscle hypoplasia, especially in limbs
- Q: What is the significance of maternal varicella infection after 20 weeks gestation? A: The risk of congenital varicella syndrome is very low, but the infant may develop herpes zoster in infancy
- Q: How does congenital varicella syndrome affect the urogenital system? A: It may cause hydroureter, hydronephrosis, and genital hypoplasia
- Q: What is the role of serial ultrasound examinations in pregnancies affected by varicella? A: To monitor for signs of fetal infection and structural abnormalities
- Q: How does congenital varicella syndrome differ from fetal varicella infection? A: Congenital syndrome involves permanent malformations, while fetal infection may result in asymptomatic or mild disease
- Q: What is the long-term prognosis for children with congenital varicella syndrome? A: Variable, depending on the severity of organ involvement, with many requiring lifelong multidisciplinary care
- Q: How does maternal shingles (herpes zoster) during pregnancy affect the fetus? A: Maternal shingles does not typically pose a risk to the fetus due to maternal antibodies
- Q: What is the recommended follow-up for infants born to mothers with varicella during pregnancy? A: Close monitoring for signs of infection and developmental assessments
