Herpes simplex encephalitis

A virus, identified as a strain of herpes simplex, was isolated from the brain of an infant who died during an illness characterized by signs of encephalitis. Acidophilic intranuclear inclusion bodies and encephalitic changes were seen in histologic sections of the brain. The absence of herpes simplex neutralizing antibodies in the patient's serum on the eighth day of illness indicated that the encephalitis represented a primary infection with the virus.