Herpesvirus infections of the neonatal CNS: Similarities and differences between HSV and CMV

Neonatal herpes simplex virus (HSV) infection is often acquired during delivery, whereas symptomatic cytomegalovirus (CMS) disease is acquired in utero. Congenial CMV disease normally presents with signs of neurological and systemic infection, which are noticeable at birth; HSV infection becomes apparent days later. Central nervous system (CNS) herpesvirus infection may be present without cutaneous or systematic signs of disease, and HSV infection must be contemplated in any infant with suspected encephalitis or meningitis. Prompt antiviral therapy with intravenous aciclovir warranted in infants with suspected HSV infection. The pathogenesis of CMV-induced damage to the neonatal CNS is not well understood and the efficacy of antiviral therapy against CMV is unconfirmed. For both viruses, however, pre-existing maternal immunity seems to offer neonatal protection.