Neonatal herpes is a serious infection affecting newborns, caused by the herpes simplex virus (HSV). It can develop within a baby’s first six weeks of life, often resulting from the virus passing from a parent to the infant. Unlike mild HSV infections in older children and adults, the virus is potentially life-threatening for newborns. Early identification and treatment are important for improving outcomes.
How Babies Acquire Herpes
Babies can acquire the herpes simplex virus through several routes, primarily during birth. The most common, perinatal transmission (about 85% of cases), occurs when the baby passes through the birth canal and comes into contact with active HSV lesions or infected secretions. Both herpes simplex virus type 1 (HSV-1), commonly associated with oral cold sores, and herpes simplex virus type 2 (HSV-2), often linked to genital infections, can cause neonatal herpes.
Intrauterine transmission (about 5% of cases) happens when the virus crosses the placenta to infect the fetus during pregnancy. This can lead to congenital herpes, sometimes resulting in severe complications like skin lesions, eye issues, or neurological damage present at birth. The risk of transmission is highest when a pregnant individual acquires a new herpes infection late in pregnancy, especially during the third trimester. This is because the body has not had sufficient time to develop antibodies against the virus, which would otherwise pass to the baby and offer some protection.
Postnatal transmission (about 10% of cases) occurs after birth through direct contact with an active herpes lesion. This can happen if a caregiver with a cold sore or herpetic whitlow (a herpes infection on the finger) kisses or touches the baby. Infants are particularly vulnerable to postnatal transmission if their parent has never had an HSV infection or had their first infection late in pregnancy, as they lack protective antibodies.
Symptoms and Effects in Infants
Neonatal herpes symptoms often appear within the first four to six weeks of life. The signs can be subtle and non-specific, making early recognition challenging. The infection is categorized into three forms based on affected areas.
Skin, Eyes, and Mouth (SEM) disease accounts for about 45% of cases. This localized infection presents with fluid-filled blisters on the skin, around the eyes, or inside the mouth. If untreated, it can progress to more severe forms, potentially causing permanent eye damage or vision loss.
Central Nervous System (CNS) disease affects about 30% of infected infants. This involves the brain and spinal cord, leading to symptoms such as lethargy, irritability, poor feeding, seizures, and unstable temperature. Even with treatment, CNS disease can result in long-term neurological complications, including developmental delays, intellectual disability, cerebral palsy, or epilepsy.
Disseminated disease occurs in about 25% of cases. This widespread infection affects multiple internal organs like the liver, lungs, and adrenal glands, often resembling sepsis. Infants may exhibit non-specific symptoms such as fever, respiratory distress, jaundice, and bleeding issues. This form carries a significant mortality rate, and survivors often experience long-term neurological consequences.
Prevention and Management
Preventing neonatal herpes involves several strategies for pregnant individuals. They should inform healthcare providers about any history of herpes, including cold sores or genital herpes. For those with recurrent genital herpes or a new infection during pregnancy, antiviral medication (e.g., acyclovir or valacyclovir) may be recommended from 36 weeks gestation until delivery. This suppressive therapy reduces the likelihood of an outbreak around birth, lowering transmission risk.
If a pregnant individual has active genital herpes lesions or symptoms of an impending outbreak at labor onset, a Cesarean section (C-section) is recommended. This prevents the baby from contacting the virus in the birth canal. Postnatal prevention includes urging anyone with active cold sores or other herpes lesions to avoid direct contact with newborns, especially kissing. Caregivers should wash hands thoroughly before handling the baby and cover any active lesions.
When neonatal herpes is suspected or diagnosed, immediate hospitalization and intravenous antiviral medication, such as acyclovir, are necessary. Treatment duration varies by disease classification: SEM disease usually requires 14 days, while CNS or disseminated disease requires a minimum of 21 days. Early initiation of antiviral therapy significantly improves outcomes and reduces morbidity and mortality. After initial intravenous treatment for CNS or disseminated infection, a baby may receive oral suppressive therapy for several months to reduce the risk of long-term neurological problems and future outbreaks.