Varicella-zoster virus (VZV) is found worldwide and is very contagious.[1]Centers for Disease Control and Prevention. CDC Yellow Book 2024: health information for international travel. Section 5: travel-associated infections & diseases - viral. Varicella/chickenpox. May 2023 [internet publication].
https://wwwnc.cdc.gov/travel/yellowbook/2024/infections-diseases/varicella-chickenpox
The virus is more prevalent in temperate climates, and outbreaks are more common in late winter and spring.[2]Lin F, Hadler JL. Epidemiology of primary varicella and herpes zoster hospitalizations: the pre-varicella vaccine era. J Infect Dis. 2000 Jun;181(6):1897-905.
http://jid.oxfordjournals.org/content/181/6/1897.full
http://www.ncbi.nlm.nih.gov/pubmed/10837168?tool=bestpractice.com
Serosurveys in the US before vaccination was introduced have shown that more than 90% of individuals had VZV antibodies in adolescence and nearly 100% by adulthood.[3]Kilgore PE, Kruszon-Moran D, Seward JF, et al. Varicella in Americans from NHANES III: implications for control through routine immunization. J Med Virol. 2003;70 Suppl 1:S111-8.
http://www.ncbi.nlm.nih.gov/pubmed/12627498?tool=bestpractice.com
The greatest incidence of varicella is in children 1 to 9 years of age, but in tropical climates, particularly in rural areas with smaller population densities, the disease is often acquired in adulthood.[1]Centers for Disease Control and Prevention. CDC Yellow Book 2024: health information for international travel. Section 5: travel-associated infections & diseases - viral. Varicella/chickenpox. May 2023 [internet publication].
https://wwwnc.cdc.gov/travel/yellowbook/2024/infections-diseases/varicella-chickenpox
[4]Mandal BK, Mukherjee PP, Murphy C, et al. Adult susceptibility to varicella in the tropics is a rural phenomenon due to the lack of previous exposure. J Infect Dis. 1998 Nov;178 Suppl 1:S52-4.
http://www.ncbi.nlm.nih.gov/pubmed/9852974?tool=bestpractice.com
[5]Ooi PL, Goh KT, Doraisingham S, et al. Prevalence of varicella-zoster virus infection in Singapore. Southeast Asian J Trop Med Public Health. 1992 Mar;23(1):22-5.
http://www.ncbi.nlm.nih.gov/pubmed/1523475?tool=bestpractice.com
Estimated hospital admission rates for varicella in developed countries range from 2 to 6 per 100,000 people and appear to be higher in African-American people and non-white Hispanic people.[6]Heininger U, Seward JF. Varicella. Lancet. 2006 Oct 14;368(9544):1365-76.
http://www.ncbi.nlm.nih.gov/pubmed/17046469?tool=bestpractice.com
[Figure caption and citation for the preceding image starts]: African patient with varicellaImage provided by the CDC and the Public Health Image Library [Citation ends].
Immunocompromised patients are at greater risk of complications and mortality. The mortality rate due to varicella is low. In 2012-2016, the annual average age-adjusted mortality rate for varicella was 0.03 per million population, which is a reduction of 94% compared with prevaccine period, and a 47% reduction compared with the period 2005-2007.[7]Leung J, Marin M. Update on trends in varicella mortality during the varicella vaccine era-United States, 1990-2016. Hum Vaccin Immunother. 2018;14(10):2460-3.
https://www.tandfonline.com/doi/full/10.1080/21645515.2018.1480283
http://www.ncbi.nlm.nih.gov/pubmed/29939802?tool=bestpractice.com