Neonatal case of herpes simplex virus encephalitis after delivery from a woman whose genital herpes simplex virus infection had been treated with acyclovir.

A case of herpes simplex virus (HSV) encephalitis in a neonate after delivery from a woman whose genital HSV infection had been treated with acyclovir is reported. The main approach to prevent genital HSV infection in the neonate is interruption of transmission at the time of delivery. Guidelines for prophylactic therapy with acyclovir have been established, but the risk of neonatal infection remains. A fever began to develop in a male neonate delivered vaginally from a 35-year-old woman. Treatment with intravenous acyclovir was started on the basis of a diagnosis of HSV encephalitis, because polymerase chain reaction was positive for HSV in the cerebrospinal fluid. The mother had had a first genital HSV infection during the second trimester, but treatment with injected acyclovir had caused the blisters and erosion to resolve by the time of delivery. Important steps for preventing neonatal HSV infection are the appropriate treatment of mothers with a history of genital HSV infection, the assessment of delivery methods, and the appropriate treatment of neonates.