neonatal herpes simplex

neonatal herpes simplex
Name	Neonatal herpes simplex
Field	Pediatrics, Neonatology, Infectious disease
Symptoms	Skin lesions, seizures, respiratory distress, lethargy
Complications	Encephalitis, disseminated infection, long-term neurodevelopmental impairment
Onset	Perinatal period
Causes	Herpes simplex virus type 1, Herpes simplex virus type 2
Risks	Maternal primary infection, prolonged rupture of membranes, invasive obstetric procedures
Diagnosis	PCR, viral culture, antigen detection, CSF analysis
Treatment	Intravenous acyclovir, supportive care
Frequency	Rare

neonatal herpes simplex is a perinatal infectious disease caused by herpes simplex virus type 1 and herpes simplex virus type 2 that presents in the first 28 days of life with variable involvement of skin, eyes, mouth, central nervous system, and systemic organs. It remains a major cause of neonatal morbidity and mortality in settings where obstetric screening and antiviral prophylaxis are incomplete. Early recognition and rapid initiation of intravenous antiviral therapy substantially reduce mortality and improve neurologic outcomes.

Signs and symptoms

Neonates typically present with localized cutaneous lesions, systemic sepsis-like features, or focal central nervous system signs. Skin findings often include vesicles, ulcerations, or scabbing concentrated on the face, scalp, or trunk; fevers, poor feeding, and irritability are common systemic signs. Progression to seizures, altered consciousness, or bulging fontanelle indicates central nervous system involvement, while respiratory distress, liver dysfunction, coagulopathy, and disseminated intravascular complications signify systemic spread. Presentation can mimic bacterial sepsis, perinatal asphyxia, or congenital infections such as cytomegalovirus and varicella, necessitating broad differential considerations in neonatal intensive care.

Virology and pathogenesis

Herpes simplex virus (HSV) is an enveloped double-stranded DNA virus of the Herpesviridae family; both HSV-1 and HSV-2 establish latent infection in sensory ganglia after mucocutaneous infection. Vertical acquisition during the intrapartum period allows infection of mucous membranes and skin, followed by local replication and potential neuroinvasion via retrograde axonal transport to dorsal root or cranial nerve ganglia. Host factors including neonatal immature innate immunity, deficient interferon responses, and lower maternal neutralizing antibody titers permit uncontrolled viral replication and hematogenous dissemination to liver, lung, and brain. Viral tropism for neural tissue underlies the predilection for encephalitis, while direct cytopathic effects, immune-mediated inflammation, and coagulopathy contribute to organ dysfunction.

Transmission and risk factors

Transmission occurs primarily during passage through an infected birth canal but may also occur in utero after transplacental spread or postnatally through close contact with caregivers shedding HSV on orolabial or genital mucosa. Highest risk is associated with maternal primary HSV infection near delivery, prolonged rupture of membranes, operative vaginal delivery with fetal scalp electrodes, and maternal lesions or prodromal symptoms at labor. Epidemiologic patterns vary by geography, with differing prevalences of HSV-1 and HSV-2 linked to sexual health practices and screening policies; obstetric guidelines from major institutions inform intrapartum management, antiviral suppression, and decisions regarding cesarean delivery.

Diagnosis

Diagnosis relies on detection of HSV from lesions, blood, cerebrospinal fluid, or other sterile sites using polymerase chain reaction, viral culture, or direct antigen testing. Cerebrospinal fluid analysis with PCR for HSV DNA is essential when central nervous system involvement is suspected; neuroimaging with cranial ultrasonography, computed tomography, or magnetic resonance imaging may reveal temporal lobe abnormalities. Serologic testing of maternal and neonatal antibodies can assist in epidemiologic assessment but is limited in the acute setting. A high index of suspicion is warranted in neonates with sepsis-like illness, seizures, or vesicular lesions; protocols from pediatric hospitals and perinatal centers standardize specimen collection and empiric antiviral initiation pending confirmation.

Treatment and management

Intravenous acyclovir is the cornerstone of therapy, with dosing and duration determined by disease classification—skin, eye, mouth disease versus central nervous system or disseminated disease—followed by oral suppressive therapy in selected cases. Supportive care in neonatal intensive care units addresses respiratory support, hemodynamic stabilization, management of coagulopathy, and seizure control with anticonvulsant regimens. Prevention strategies include maternal antiviral suppression in late pregnancy for women with recurrent genital herpes, consideration of cesarean delivery for active lesions at labor, and strict hygiene practices among caregivers; public health organizations and obstetric societies provide recommendations for peripartum management and newborn evaluation.

Prognosis and complications

Outcomes depend on timing of infection, extent of organ involvement, and promptness of antiviral therapy. Localized mucocutaneous disease generally carries a favorable prognosis with brief antiviral therapy, whereas disseminated disease and HSV encephalitis carry high risks of mortality and long-term neurodevelopmental impairment including motor deficits, cognitive delays, hearing loss, and epilepsy. Survivors of neonatal encephalitis often require multidisciplinary follow-up with neurology, developmental pediatrics, audiology, and physical therapy. Long-term studies from tertiary referral centers and pediatric consortia document persistent morbidity despite antiviral advances, underscoring the need for prevention, early detection, and standardized care pathways.

Category:Neonatal infections