What are the risks of neonatal herpes simplex virus (HSV) exposure?

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Last updated: April 15, 2025 • View editorial policy

From the Guidelines

Infants exposed to herpes simplex virus (HSV) require immediate medical attention, and treatment typically involves intravenous acyclovir at 20 mg/kg body weight/dose three times daily for 14-21 days, depending on the extent of infection, as recommended by the CDC and the Infectious Diseases Society of America 1.

Key Considerations

  • Neonatal HSV infection can appear as disseminated multiorgan disease, localized disease of the CNS, or disease localized to the skin, eyes, and mouth, with varying presentations and outcomes 2.
  • The risk of transmission from an HSV-infected mother to her infant is significant, occurring primarily through exposure to HSV-infected maternal genital fluids during passage through the birth canal, and can result in severe complications if left untreated 3.
  • Prevention strategies include careful hand hygiene and avoiding contact between the infant and anyone with active herpes lesions.

Diagnosis and Treatment

  • Infants with suspected HSV exposure should be evaluated by a healthcare provider immediately, even if they show no symptoms, and undergo blood tests, spinal fluid analysis, and viral cultures before starting treatment.
  • Acyclovir is the drug of choice for treatment of HSV among infants and children, regardless of HIV-infection status, and should be administered for 21 days for CNS and disseminated disease and for 14 days for skin, eye, and mouth disease 1.
  • Parents should watch for symptoms including skin vesicles, fever, lethargy, poor feeding, seizures, or respiratory distress, and seek medical attention immediately if they occur.

Outcomes and Prognosis

  • Despite treatment, infants with neonatal HSV infection remain at risk for neurologic sequelae, with the most severe neurologic sequelae seen in those with CNS disease 1.
  • A limited percentage of infants with localized skin, eye, or mucus membrane disease might have later neurologic sequelae after apparently successful treatment 1.

From the Research

Infant Herpes Simplex Exposure

  • Herpes simplex virus (HSV) infections in newborns can have severe consequences, including high morbidity and mortality rates 4.
  • The treatment of HSV infections in infants typically involves the use of antiviral drugs, with acyclovir being the primary choice 5, 6, 7.
  • Acyclovir can be administered intravenously or orally, with high-dose acyclovir (60 mg/kg/d) being recommended for the treatment of neonatal HSV infections 5.
  • However, the safety of high-dose acyclovir in infants has not been extensively studied, and it is not currently approved by the US Food and Drug Administration for use in this population 5.
  • Studies have shown that acyclovir is generally well-tolerated in infants, with common adverse events including hypotension, seizure, and thrombocytopenia 5.
  • Oral acyclovir may be used as suppressive therapy after acute treatment completion in specific neonatal populations, reducing long-term adverse neurodevelopmental outcomes and future skin eruptions 4.
  • Despite advances in treatment, neonatal HSV disease continues to have an unacceptably high mortality rate, and further research is needed to improve prevention and treatment strategies 8.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.