VZV: persistence in the population: transmission and epidemiology

Publisher Website
Google Scholar
Abstract
Like other herpes viruses, varicella zoster virus (VZV) causes disease due to the primary infection (varicella) and due to reactivation (herpes zoster). However, VZV differs from other herpes viruses in causing primary and reactivation infections that are easily recognized clinical diseases, even by the lay public. Because of this, the epidemiology of varicella and herpes zoster has been well described from clinically recognized disease (incidence, severe disease outcomes and deaths) with seroprevalence data providing additional information on the epidemiology of varicella especially in populations where varicella disease history may not be available. Varicella occurs worldwide with ongoing endemic transmission in areas where populations are sufficiently large to support such transmission. However the epidemiology of varicella varies between temperate and tropical climates (Lee, 1998). Universal childhood vaccination programs have changed the epidemiology of varicella in countries implementing such programs with significant declines in disease. Most experience has been gained in the United States where a varicella vaccination program was initiated in 1995. Herpes zoster infections also occur throughout the world although the epidemiology of herpes zoster is less well described globally. Because the incidence of herpes zoster increases dramatically with age, countries with lower life expectancies may have lower health burdens due to this disease. A vaccine for prevention of herpes zoster and post-herpetic neuralgia was licensed in the USA in May, 2006 (Oxman et al., 2005). This chapter reviews pre- and post-vaccine epidemiology of varicella and herpes zoster.