Key Takeaways on Herpes and Newborns
Neonatal herpes is rare but serious; prompt recognition and antiviral treatment improve outcomes. Most babies are born after exposure to maternal or community HSV and do not develop infection. Understanding routes, timelines, and prevention helps caregivers manage risk and seek timely care.
What Is Neonatal Herpes
Neonatal herpes is infection with herpes simplex virus acquired around birth or shortly after. It differs from congenital herpes, which is passed before birth. Transmission is usually from the mother, though community sources can also contribute. Infection is categorized by timing and extent: skin, eye, and mouth disease; encephalitis; or disseminated disease affecting multiple organs. Early recognition and treatment are associated with better outcomes.
Definitions and Clinical Categories
- Neonatal herpes: HSV infection acquired perinatally or in the early neonatal period.
- Congenital herpes: Very rare transmission before birth through the placenta.
- SEM disease: Localized skin, eye, and mouth involvement.
- Encephalitis: Central nervous system infection.
- Disseminated disease: Multiorgan involvement, often including liver and lungs.
How Transmission Occurs
Most neonatal cases arise from exposure to HSV in the birth canal during vaginal delivery. The infant may acquire virus from an active outbreak or asymptomatic shedding. Less commonly, transmission follows procedures involving oral-genital contact or contaminated caregivers' secretions. Factors increasing risk include first-episode maternal infection near delivery, multiple vaginal examinations, use of fetal scalp electrodes, and preterm rupture of membranes.
Risk Factors and Preventable Scenarios
- Primary maternal HSV near term: Highest viral shedding and lack of antibodies.
- Recurrent maternal infection: Lower, but present, risk of shedding.
- Invasive fetal monitoring or instrumentation: Potential microtrauma.
- Prolonged rupture of membranes: Increased exposure time.
Signs and Timing of Illness
Symptoms typically appear within the first four weeks of life, with most cases identified by two weeks. Early-onset disease (0–7 days) is often disseminated or encephalitic and linked to in utero or intrapartum transmission. Classic presentation includes skin vesicles or ulcers, eye redness, mouth ulcers, fever, lethargy, irritability, seizures, or poor feeding. Atypical or late-onset cases can occur, especially from community sources or postnatal contact.
Clinical Features by Category
| Category | Common Manifestations | Typical Onset |
|---|---|---|
| SEM disease | Skin vesicles or ulcers, conjunctivitis, mucositis | Birth to 4 weeks |
| Encephalitis | Seizures, lethargy, irritability, temperature instability, bulging fontanelle | Birth to 4 weeks |
| Disseminated | Fever, poor perfusion, hepatomegaly, coagulopathy, respiratory distress | Birth to 4 weeks |
Diagnosis and Testing
Diagnosis relies on a high index of suspicion and timely testing. Clinicians collect samples from lesions, mucosal surfaces, blood, cerebrospinal fluid, and other sterile sites for PCR and viral culture. A multidisciplinary approach involving pediatrics, neonatology, and infectious diseases supports interpretation. Rapid PCR results can guide therapy. Serology in infants has limited utility because maternal antibodies cross the placenta; paired infant serology or rising antibody titers may help in select cases.
Key Diagnostic Tools
- Swab PCR for skin, eye, mouth lesions.
- Blood PCR and culture.
- Cerebrospinal fluid PCR and cell count.
- Multidisciplinary review when results are indeterminate.
Prevention and Risk Management
Prevention centers on identifying risk factors in pregnancy and planning safe delivery. For women with primary first-episode HSV near delivery, providers often recommend cesarean delivery to reduce exposure risk. Antiviral suppression from 36 weeks may lower shedding and clinical recurrence. Avoid procedures that facilitate viral entry, and practice meticulous hygiene among caregivers to prevent postnatal transmission. These strategies substantially reduce but do not eliminate transmission risk.
Prevention Checklist for Families
- Discuss HSV history and recent symptoms with your obstetric team.
- Follow recommended delivery timing and mode based on clinical factors.
- Begin antiviral suppression in late pregnancy when indicated.
- Limit close contact with active oral or genital sores in caregivers.
- Wash hands thoroughly before holding or feeding the baby.
Treatment and Outcomes
Neonatal herpes is treated with intravenous antivirals, typically acyclovir, for 14–21 days depending on the category and severity. Early therapy is associated with reduced mortality and fewer long-term complications. Supportive care includes respiratory, neurologic, and nutritional support. Outcomes are best when SEM disease is treated promptly, while disseminated and encephalitic cases carry higher risks of neurodevelopmental sequelae. Long-term follow-up may include neurodevelopmental assessments and audiology or ophthalmology evaluation.
Prognostic Factors at a Glance
| Disease Category | Mortality with Treatment | Neurodevelopmental Risk |
|---|---|---|
| SEM disease | Low with treatment | Low if treated early |
| Encephalitis | Low to moderate with treatment | Moderate, may require rehabilitation |
| Disseminated | Higher with treatment | Variable; depends on organ involvement |
Care and Follow-Up
After discharge, families should understand warning signs, medication safety, and follow-up plans. Keep a record of medications, clinic visits, and test results. Coordinate with pediatricians and specialists to monitor growth, development, and medication side effects. Education about transmission and hygiene helps protect the infant and household members. Emotional support and clear communication with the care team reduce uncertainty and promote adaptive coping.