Herpes Simplex Virus Infections of the Central Nervous System

Purpose of the Review: This article summarizes knowledge of herpes simplex virus (HSV) infections of the central nervous system (CNS). Disease pathogenesis, detection of DNA polymerase chain reaction (PCR) for diagnosis and prognosis, and approaches to therapy warrant consideration.

Recent Findings: HSV infection of the CNS is one of few treatable viral diseases. Clinical trials indicate that outcome following neonatal herpes simplex virus type 2 (HSV-2) infections of the CNS is significantly improved when 6 months of suppressive oral acyclovir therapy follows IV antiviral therapy. In contrast, herpes simplex virus type 1 (HSV-1) infections of the brain do not benefit from extended oral antiviral therapy. This implies a difference in disease pathogenesis between HSV-2 and HSV-1 infections of the brain. PCR detection of viral DNA in the CSF is the gold standard for diagnosis. Use of PCR is now being adopted as a basis for determining the duration of therapy in the newborn.

Summary: HSV infections are among the most common encountered by humans; seropositivity occurs in 50% to 90% of adult populations. Herpes simplex encephalitis, however, is an uncommon result of this infection. Since no new antiviral drugs have been introduced in nearly 3 decades, much effort has focused on learning how to better use acyclovir and how to use existing databases to establish earlier diagnosis.

Address correspondence to Dr Richard J. Whitley, Suite 303, Children’s Harbor Building, 1600 7th Avenue South, Birmingham, AL 35233, [email protected].

Relationship Disclosure: Dr Whitley has served on the board of directors of Gilead Sciences, Inc, and has received personal compensation as a consultant for the GSK Watermark Zoster Study, Merck Letermovir Data and Safety Monitoring Board, Multiparty Group for Advice on Science (MUGAS) Influenza Data Oversight, and N&N Scientific, Inc. Dr Whitley has received personal compensation from the Journal of Antiviral Therapy for serving as section editor and from the Journal of Infectious Diseases for serving as associate editor. Dr Whitley has received personal compensation for speaking engagements from The George Washington University Continuing Medical Education Program, Harvard University, Hospital Pediátrico de Coimbra, Infectious Diseases Society of America, International Herpesvirus Workshop, Japan Herpesvirus Infections Forum, The Ohio State University, State University of New York, Plattsburgh, University of Oxford, and University of Pittsburgh.

Unlabeled Use of Products/Investigational Use Disclosure: Dr Whitley reports no disclosure.