A Global Perspective of the Epidemiology and Burden of Varicella-Zoster Virus

The global burden of disease associated with Varicella-Zoster Virus (VZV), the aetiological agent of chickenpox and shingles, can no longer be considered insignificant. This review provides a comprehensive insight in to the epidemiology of VZV in different settings. High childhood incidence rates are seen in temperate climates and substantial evidence is presented regarding the morbidity associated with primary infection both in children and high risk groups. The increased adult prevalence of disease in warmer countries is associated with significantly higher rates of complications and death. The disparities in age specific incidence of chickenpox maybe associated with decreased viral transmission in warmer temperatures, in rural settings and in high humidity. However, these factors were not always consistent especially in Australia and South American countries. This suggests the possible role of other undefined host and viral factors. Universal childhood vaccination has resulted in a dramatic decrease in incidence, hospitalisations and deaths associated with VZV in the USA. A two dose schedule is now recommended following evidence of increased incidence of breakthrough disease in vaccine recipients over time. In addition a vaccine to prevent zoster has recently been recommended for use in the elderly to address the significant burden posed by this illness on health resources in temperate countries. Keywords: Varicella-Zoster Virus (VZV), chickenpox and shingles, epidemiology, morbidity and mortality, vaccines, climates