Herpes simplex virus infection in young infants during 2 decades of empiric acyclovir therapy.

Objective: To describe the clinical presentation of HSV-infected young infants and to seek distinctive features that could permit a targeted approach to empiric use of acyclovir.

Methods: Case study of neonatal HSV during a 22-year period of an institutional strategy of consistent use of acyclovir empirically in all infants with onset of an illness at ≤ 21 days of age for which antibiotics were given empirically. Multiple sources were used to optimize HSV case data, and to estimate the rate of HSV infection in empirically treated infants.