Herpes simplex type II encephalitis in infancy presenting with focal encephalitis

Herpes virus was recovered from a throat swab, nasopharyngeal washings as well as from brain tissue from a six-month-old infant, who presented with fever, left focal seizures and an enhancing right frontal CT-scan lesion. Cytopathic effect (CPE) as seen with genital herpetic infection was seen, suggesting HSV-2. Immunofluorescent typing of the virus isolate confirmed HSV-2. Early IgM positivity preceding a CF and SN titer rise was observed. The patient received a course of ARA-A and recovered with a left sided hemiparesis. HSV-2 encephalitis occurs beyond the newborn period as a primary infection. In adults however HSV-2 encephalitis occurs predominantly in the immunocompromised host. HSV-1 encephalitis probably is due to reactivation of a latent herpetic infection in previous virus exposed juvenile or adult immunocompetent hosts.