Congenital Herpes Simplex Virus

Summary

Congenital HSV, mainly HSV-2, transmitted perinatally, rarely in utero or postnatally. Neonates may develop vesicular skin/eye/mouth lesions, CNS disease, or disseminated sepsis-like illness. Diagnosis uses viral culture or PCR, treatment is IV acyclovir, and prevention includes maternal antivirals and cesarean delivery for active lesions.

Epidemiology

 Congenital herpes simplex virus (HSV) infection occurs in approximately 1 in 3,000–10,000 live births. Most cases are caused by HSV-2, though HSV-1 can occasionally be implicated.

Pathogenesis and Transmission

 Transmission of HSV to the neonate can occur in three ways:

• Intrauterine (transplacental) infection: Rare, often associated with severe outcomes including fetal demise.

• Perinatal infection: The most common route, occurring during vaginal delivery from a mother with active genital lesions, particularly if primary maternal infection occurs near term (~30% transmission risk).

• Postnatal infection: Rare, through direct contact with active lesions (e.g., cold sores).

Clinical Manifestations

 HSV infection in neonates presents in three primary forms:

1. Skin, Eye, and Mouth (SEM) Disease:

• Vesicular mucocutaneous lesions

• Keratoconjunctivitis and potential chorioretinitis

2. Central Nervous System (CNS) Disease:

• Meningoencephalitis presenting with fever, lethargy, irritability, poor feeding, seizures, and bulging fontanelle

• Temporal lobe involvement may result in hemorrhage and edema

• Vesicular lesions may or may not be present

3. Disseminated Disease:

• Resembles sepsis, with multi-organ involvement (liver, CNS, lungs, heart, adrenal glands, kidneys, gastrointestinal tract)

• Vesicular lesions may appear late

Intrauterine HSV infection (~5% of cases) can lead to fetal demise, preterm birth, low birth weight, microcephaly, hydrocephalus, microphthalmia, chorioretinitis, and vesicular skin lesions

Diagnosis

• Mother: Usually clinical diagnosis based on lesions and history.

• Fetus: Ultrasound may detect CNS abnormalities.

• Newborn:

• Viral culture from skin, conjunctiva, oropharynx, nasopharynx, or rectum

• PCR for HSV DNA in blood or cerebrospinal fluid

Treatment

• Mother and newborn: Intravenous acyclovir or oral valacyclovir.

• Supportive care in neonates: Management of fluid/electrolyte imbalances, septic shock, seizures, and secondary infections.

Prevention

• Maternal antiviral therapy (acyclovir) starting at 36 weeks in women with known HSV history

• Cesarean delivery for women with active genital lesions or prodromal symptoms
  
  

Clinical Considerations

• HSV should be suspected in infants up to 6 weeks of age with vesicular skin lesions, persistent fever despite negative cultures, or signs of meningitis, encephalitis, or sepsis.

• Early recognition and treatment are critical to reduce morbidity and mortality.