Advances in the diagnostics of Varizella zoster virus and importance of vaccination1

Abstract

Abstract Varizella zoster virus (VZV) belongs to one of the eight herpes viruses known to infect humans. While primary VZV infection (chickenpox) is generally a disease of childhood, herpes zoster occurs primarily in elderly persons (>50 years). Herpes zoster, also called shingles, is a neurocutaneous disease resulting from reactivation of latent varizella zoster virus infection within dorsal root ganglia. Severe complications may occur in elderly and in immuno-compromised persons, including severe complication of the eye, the ear, the skin, internal organs, and the peripheral and central nervous system. A progressive decline of VZV-specific cell-mediated immunity and age are associated with an increased incidence and severity of herpes zoster and postherpetic neuralgia (PHN). PHN is the most common complication of herpes zoster causing chronic, debilitating pain. In cases with characteristic signs and symptoms (presence of prodromal pain, eruptions, grouped vesicles, segmental pain) the diagnosis is almost distinctive enough and no laboratory investigations are required. However, for patients lacking no characteristic pathology, a rapid laboratory diagnosis may be helpful to start antiviral therapy as soon as possible. Antiviral therapy should be initiated immediately within 72 h after onset of rash particularly in older patients. The major aim of treatment is to control and reduce the acute zoster pain, to shorten virus replication, to avoid dissemination of skin lesions and to prevent PHN and other severe complications The aim of the present review is to outline advantages and disadvantages of different laboratory methods of herpes zoster (microscopy, direct immunofluorescence assay, detection of viral DNA, virus isolation and serological methods. A live attenuated VZV vaccine has been developed to prevent herpes zoster and postherpetic neuralgia in individuals beyond 60 years of age (Shingles Prevention Study). This review summarises the epidemiology, pathogenesis, clinical aspects, complications, therapy and prevention of varizella zoster.