vidualization of duration of treatment based on follow-up CSF analysis with quantification of HSV-1. Herpes simplex virus-1 (HSV-1) encephalitis (HSE) in adults is associated with severe morbidity despite improvements in mortality related to treatment with acy-

Herpes simplex virus-1 (HSV-1) is the most common cause of lethal sporadic encephalitis. Despite improved therapy with intraveneous acyclovir, HSV-1 encephalitis is associated with persistent severe neurological deficits. We report three cases of adult patients with HSV-1 encephalitis (HSE), discuss the current accepted guidelines for treatment as published by the Infectious Disease Society of America (IDSA) and review the literature pertaining to HSE. Our case presentations are consistent with the literature review noting a broad spectrum of clinical outcomes with HSE. We include the first published case of successful early transition to oral antiviral therapy. In the other two cases, repeat cerebrospinal fluid (CSF) analysis showed persistent lymphocytic pleocytosis necessitating prolonged viral suppression. Long-term neurological sequelae were noted in these two patients. The IDSA recommendation of 2–3 weeks of intraveneous acyclovir at 10 mg/kg every 8 h, depending on the clinical course, is sufficient for most cases of HSE. We recommend individualization of duration of treatment based on follow-up CSF analysis with quantification of HSV-1.