Neonatal herpes simplex virus, or HSV, is transmitted from an actively infected mother to baby. Transmission can occur in utero, if infection ascends through the cervix and vagina, or during labor as the infant passes through the vagina. HSV can be transmitted even when the mother has no signs of active infection, according to the American Family Physician March 15, 2002 article by lead author Caroline Rudnick entitled "Neonatal Herpes Simplex Virus Infections". Most HSV infections in neonates are caused by HSV-2 in the United States. Symptoms can be severe.
Congenital HSV Symptoms
Four percent of neonates infected with HSV have congenital HSV. Congenital HSV is associated with small head size, or microcephaly, hydrocephalus or fluid buildup in the skull, and skin lesions. Choreoretinits, or inflammation in the middle part of the eye, the uvea, may also occur, according to Rudnick. Congenital defects are not reversible with treatment.
SEM Disease Symptoms
SEM disease means disease limited to the skin, eyes and mouth. SEM does not manifest until 10 to 11 days of age. Symptoms are lesions or vesicles, small clear blisters on the skin, and keratoconjunctivitis of the eyes. Without antiviral treatment, 30 to 40 percent of infants will develop neurological deficiencies and central nervous system or disseminated infection, Dr. David Kimberlin of the University of Alabama states in his 2004 article titled "Herpes Simplex Virus, Meningitis and Encephalitis in Neonates."
Central Nervous System Disease Symptoms
Central nervous system, or CNS, disease alone occurs in 35 percent of infants infected with HSV, and is manifested by seizures, lethargy, irritability, poor feeding, temperature instability and bulging fontanelle. Mortality rate is nearly 50 percent if treatment isn't initiated, and even with treatment, 70 percent of those who survive have neurological damage, according to Kimberlin.
Disseminated Infection Symptoms
Disseminated infection, which affects multiple sites, is seen in 22 percent of affected neonates and carries the highest risk of mortality. The central nervous system, lungs, liver, skin, eyes and mouth can all be affected. Symptoms usually occur between 9 and 11 days of age and can include seizures, shock, jaundice, spontaneous bleeding and respiratory distress. Eighty-five percent of infants not treated will die. After anti-viral treatment, survival rate is 70 percent; 15 percent will suffer neurological defects, Kimberlin explains. Seventy-five percent will be affected with encephalitis, acute brain inflammation.
