What is the recommended treatment for a baby born to a mother with an active Herpes Simplex Virus (HSV) infection?

Treatment for Babies Born to Mothers with Active Herpes Infection

All infants who have evidence of neonatal herpes should be promptly evaluated and treated with systemic acyclovir at a dose of 30-60 mg/kg/day intravenously. 1

Risk Assessment and Management Approach

The management of infants born to mothers with active herpes infection depends on several key factors:

1. Maternal Infection Status

• Primary HSV infection: Highest risk (30-50% transmission rate) 1, 2
• Recurrent HSV infection: Lower risk (0-5% transmission rate) 1

2. Exposure Classification

• Confirmed exposure: Virus isolation from infant or visible lesions
• Suspected exposure: Born through infected birth canal without visible lesions

Treatment Algorithm

For Infants with Clinical Evidence of HSV Infection:

• Immediate IV acyclovir (30-60 mg/kg/day) 1
• Obtain diagnostic samples from:
  • Blood
  • Skin vesicles (if present)
  • Mouth/nasopharynx
  • Eyes
  • Urine
  • Stool/rectum 1
• Continue treatment for 14-21 days depending on extent of disease

For Asymptomatic Infants with High-Risk Exposure:

• Infants born to mothers with primary HSV infection near term:
  • Some experts recommend empiric acyclovir therapy 1
  • Obtain surveillance cultures from mucosal surfaces 1
  • Monitor closely for development of symptoms

For Asymptomatic Infants with Lower-Risk Exposure:

• Infants born to mothers with recurrent HSV lesions:
  • Close clinical monitoring
  • Surveillance cultures may be considered
  • Routine use of acyclovir is not supported by available data 1

Clinical Presentations of Neonatal HSV

Neonatal HSV can present in three forms, each requiring prompt recognition and treatment:

1. Disseminated disease (25% of cases):

   • Appears around 9-11 days of age
   • Involves multiple organs
   • Encephalitis in 60-75% of these infants
   • Vesicular rash in approximately 60% 1

2. CNS disease (35% of cases):

   • Localized to the central nervous system
   • May present with seizures 1, 3

3. Skin, eye, and mouth (SEM) disease (40% of cases):

   • Vesicular rash in approximately 80% of cases
   • Appears around 10-11 days of age 1

Important Considerations

• Early treatment is critical for improved outcomes, particularly for disseminated and CNS disease 3
• Mortality is significantly reduced with prompt antiviral therapy 4
• Long-term neurological follow-up is essential, as only one-third of children with herpes encephalitis have normal development 3
• Consultation with an infectious disease expert is recommended for management of these cases 1

Prevention Strategies

• Cesarean delivery for women with active genital lesions at the time of labor 2
• Maternal suppressive therapy with valacyclovir (500mg twice daily) or acyclovir (400mg three times daily) starting at 36 weeks' gestation can reduce viral shedding and recurrences 2
• Avoid invasive procedures during labor that might disrupt fetal skin integrity (e.g., fetal scalp monitoring) 1

Common Pitfalls to Avoid

• Delayed treatment: Do not wait for confirmation of HSV infection before initiating therapy in symptomatic infants
• Inadequate evaluation: Ensure comprehensive sampling for HSV detection
• Insufficient treatment duration: Complete the full course of antiviral therapy
• Overlooking CNS involvement: Consider HSV in the differential diagnosis for any infant 2-4 weeks of age with seizures 3
• Neglecting long-term follow-up: Neurological monitoring is essential for survivors of neonatal HSV infection

Early diagnosis and prompt treatment are critical factors in improving outcomes for infants with neonatal HSV infection.