Herpes Simplex Virus (HSV)

HSV-1 is usually transmitted during childhood through contact with oral secretions (cold sores). Seroprevalence studies indicate about 60% of adults in the United States are infected with this virus. HSV-2 is usually spread by sexual contact (genital herpes). Consequently, this infection usually occurs later in life and the seroprevalence rates vary dramatically by geographic region. Both HSV-1 and HSV-2 establish a lifelong, latent infection in the nervous system and there is no cure. Antiviral medications can reduce the frequency, duration and severity of outbreaks and over a period of several years, many infected individuals experience less severe symptoms and fewer outbreaks, although they are still contagious to others. The risk for neonatal herpes is greatest when a mother acquires HSV infection for the first time in late pregnancy in part because the levels of HSV in the genital tract are highest early in infection. Many infants infected with HSV are born prematurely and approximately 4% can develop congenital HSV which has serious consequences including death.

Congenital Disease

In most cases, babies contract congenital herpes in the birth canal during delivery (especially if the mother has an active outbreak of genital herpes at the time of delivery). In rare circumstances, it is possible to be infected in the uterus or immediately after birth (from being kissed or having other contact with someone who has herpes mouth sores). Congenital HSV is a serious condition and affects about 1 out of every 3,000-20,000 live births. Detection and prevention are difficult because the infected mother is typically asymptomatic. Congenital herpes symptoms usually appear within the first month of the infant’s life and antiviral treatments such as vidarabine and acyclovir have proven helpful to reduce the severity of the disease. However, infants with systemic herpes or encephalitis often do poorly, despite antiviral medications and early treatment.