Herpes simplex virus (HSV) infection, commonly known as herpes, is a widespread condition that can cause concerns for expectant parents due to the possibility of transmission from mother to baby. Understanding its effects on newborns, transmission routes, and prevention and management strategies is important for the health and well-being of both mother and child.
How Herpes is Transmitted to Infants
Herpes simplex virus can be transmitted to a baby through several routes, with the most common occurring during vaginal delivery. The most common is peripartum or vertical transmission, accounting for approximately 85% of neonatal herpes cases. This occurs when the baby comes into contact with the virus in the mother’s genital tract, particularly if active lesions are present. Even without visible sores, viral shedding can occur, posing a risk of transmission. Less common is in utero transmission (about 5% of cases), where the virus passes through the placenta to the fetus, often linked to a mother’s primary infection during pregnancy. Postnatal transmission (roughly 10% of cases) can occur after birth through direct contact with active herpes lesions from a caregiver. While both HSV-1 and HSV-2 can cause neonatal herpes, HSV-2 is generally a more frequent cause due to its prevalence in genital infections. The risk of transmission is highest if a mother acquires a primary herpes infection late in pregnancy, as she hasn’t had sufficient time to develop and pass protective antibodies to the baby.
Potential Impact on the Baby
If a baby contracts herpes, the consequences can be severe due to their underdeveloped immune system. Neonatal herpes can manifest in various ways, categorized by the areas of the body affected. The mildest form is localized disease, affecting the skin, eyes, and mouth (SEM), presenting with fluid-filled blisters on the skin, in the mouth, or around the eyes. Without prompt treatment, SEM disease can progress to more severe forms. Central nervous system (CNS) disease involves the brain and spinal cord, potentially leading to conditions like encephalitis. Infants with CNS involvement might exhibit symptoms like irritability, lethargy, seizures, or tremors. The most severe form is disseminated disease, where the virus spreads to multiple organs. Disseminated neonatal herpes carries a high mortality rate, even with treatment, and survivors often face long-term neurological damage. Prompt diagnosis and treatment are vital because the infection can spread rapidly, causing permanent disability or even death.
Strategies to Prevent Transmission
Preventing the transmission of herpes to a newborn involves several proactive measures and medical interventions. One primary strategy is antiviral therapy for pregnant individuals with a history of recurrent herpes. Healthcare providers may prescribe antiviral medications, such as acyclovir or valacyclovir, during the last month of pregnancy, typically starting around 36 weeks. This suppressive therapy aims to reduce the frequency of outbreaks and minimize the presence of active lesions or viral shedding at the time of delivery. Another preventative measure is a Cesarean section (C-section) if active genital lesions or prodromal symptoms are present at the onset of labor. A C-section helps prevent the baby from coming into contact with the virus in the birth canal during delivery. While C-sections significantly reduce transmission risk, they do not completely eliminate it. Beyond medical interventions, caregivers should avoid direct contact with active herpes lesions. Mothers with oral herpes should avoid kissing their baby during an outbreak and practice meticulous hand hygiene. Covering active lesions can also help prevent accidental transmission. Expectant parents should openly discuss their herpes status with their healthcare providers, allowing for personalized risk assessment and appropriate management throughout pregnancy and delivery.
Diagnosis and Management for Infants
If neonatal herpes is suspected, prompt diagnosis and immediate treatment are vital for improving outcomes. Diagnosis often involves testing samples from the baby, such as swabs from skin lesions, eyes, mouth, and rectum, as well as blood and cerebrospinal fluid. Polymerase chain reaction (PCR) testing is a common method for detecting HSV DNA in these samples. Once diagnosed, or even if strongly suspected, treatment with intravenous antiviral medication is initiated without delay. Acyclovir is the most commonly used antiviral for neonatal herpes and is administered intravenously for 14 to 21 days, depending on the severity and type of infection. For severe forms like CNS or disseminated disease, treatment typically lasts 21 days, followed by a six-month course of oral antiviral medication to help prevent recurrence and improve neurodevelopmental outcomes. Early recognition and rapid treatment minimize the potential for long-term complications, including neurological damage or fatality.