Epidemiology of varicella-zoster virus infection: Chickenpox
- Mary A Albrecht, MD
Mary A Albrecht, MD
- Associate Professor of Medicine
- Harvard Medical School
Varicella-zoster virus (VZV) infection causes two clinically distinct forms of disease: varicella (chickenpox) and herpes zoster (shingles). Primary VZV infection results in the diffuse vesicular rash of varicella, or chickenpox.
The epidemiology of varicella has changed dramatically since the introduction of the varicella vaccine in 1995. In the United States, routine childhood immunization has reduced disease incidence, complications, hospital admissions, and deaths in children and in the general population, indicating strong herd immunity. Similar immunization programs have been adopted by several other countries, including Uruguay, Germany, Taiwan, Canada, and Australia .
This topic will address the morbidity and mortality of varicella infection prior to and after immunization. The clinical manifestations and management of varicella are discussed elsewhere. (See "Clinical features of varicella-zoster virus infection: Chickenpox" and "Treatment of varicella (chickenpox) infection" and "Vaccination for the prevention of primary varicella infection (chickenpox)" and "Prevention and control of varicella-zoster virus in hospitals" and "Varicella-zoster virus infection in pregnancy".)
EPIDEMIOLOGY OF VARICELLA PRIOR TO VACCINE
Incidence of varicella — Varicella occurs throughout the year in temperate regions, but the incidence typically peaks in the months of March through May . According to national seroprevalence data from the prevaccine era, greater than 95 percent of persons in the United States acquired varicella before 20 years of age, and fewer than 2 percent of adults were susceptible to infection [3-6]. Prior to 1995 the Centers for Disease Control and Prevention (CDC) estimated the yearly incidence of chickenpox in the United States at approximately four million cases, with nearly 11,000 admissions and 100 deaths .
A chart review of over 250,000 members of a health maintenance organization (HMO) was conducted from 1990 to 1992 to assess the epidemiology of varicella and its complications . The following results were noted:
- Heininger U, Seward JF. Varicella. Lancet 2006; 368:1365.
- Straus SE, Ostrove JM, Inchauspé G, et al. NIH conference. Varicella-zoster virus infections. Biology, natural history, treatment, and prevention. Ann Intern Med 1988; 108:221.
- Kelley PW, Petruccelli BP, Stehr-Green P, et al. The susceptibility of young adult Americans to vaccine-preventable infections. A national serosurvey of US Army recruits. JAMA 1991; 266:2724.
- Weller TH. Varicella and herpes zoster: a perspective and overview. J Infect Dis 1992; 166 Suppl 1:S1.
- Preblud SR, Orenstein WA, Bart KJ. Varicella: clinical manifestations, epidemiology and health impact in children. Pediatr Infect Dis 1984; 3:505.
- Seward JF, Zhang JX, Maupin TJ, et al. Contagiousness of varicella in vaccinated cases: a household contact study. JAMA 2004; 292:704.
- Centers for Disease Control and Prevention (CDC). Decline in annual incidence of varicella--selected states, 1990-2001. MMWR Morb Mortal Wkly Rep 2003; 52:884.
- Choo PW, Donahue JG, Manson JE, Platt R. The epidemiology of varicella and its complications. J Infect Dis 1995; 172:706.
- Merrett P, Schwartzman K, Rivest P, Greenaway C. Strategies to prevent varicella among newly arrived adult immigrants and refugees: a cost-effectiveness analysis. Clin Infect Dis 2007; 44:1040.
- Wharton M. The epidemiology of varicella-zoster virus infections. Infect Dis Clin North Am 1996; 10:571.
- Longfield JN, Winn RE, Gibson RL, et al. Varicella outbreaks in Army recruits from Puerto Rico. Varicella susceptibility in a population from the tropics. Arch Intern Med 1990; 150:970.
- Struewing JP, Hyams KC, Tueller JE, Gray GC. The risk of measles, mumps, and varicella among young adults: a serosurvey of US Navy and Marine Corps recruits. Am J Public Health 1993; 83:1717.
- Ma H, Fontaine R, Centers for Disease Control and Prevention (CDC). Varicella outbreak among primary school students--Beijing, China, 2004. MMWR Morb Mortal Wkly Rep 2006; 55 Suppl 1:39.
- Centers for Disease Control and Prevention (CDC). Recommended childhood immunization schedule--United States, January-June 1996. MMWR Morb Mortal Wkly Rep 1996; 44:940.
- Preblud SR. Age-specific risks of varicella complications. Pediatrics 1981; 68:14.
- Centers for Disease Control (CDC). Varicella-zoster immune globulin for the prevention of chickenpox. MMWR Morb Mortal Wkly Rep 1984; 33:84.
- Dits H, Frans E, Wilmer A, et al. Varicella-zoster virus infection associated with acute liver failure. Clin Infect Dis 1998; 27:209.
- Guess HA, Broughton DD, Melton LJ 3rd, Kurland LT. Chickenpox hospitalizations among residents of Olmsted County, Minnesota, 1962 through 1981. A population-based study. Am J Dis Child 1984; 138:1055.
- Bovill B, Bannister B. Review of 26 years' hospital admissions for chickenpox in North London. J Infect 1998; 36 Suppl 1:17.
- Seward JF, Watson BM, Peterson CL, et al. Varicella disease after introduction of varicella vaccine in the United States, 1995-2000. JAMA 2002; 287:606.
- Guris D, Jumaan AO, Mascola L, et al. Changing varicella epidemiology in active surveillance sites--United States, 1995-2005. J Infect Dis 2008; 197 Suppl 2:S71.
- Sosa LE, Hadler JL. Epidemiology of varicella in Connecticut, 2001-2005. J Infect Dis 2008; 197 Suppl 2:S90.
- Marin M, Watson TL, Chaves SS, et al. Varicella among adults: data from an active surveillance project, 1995-2005. J Infect Dis 2008; 197 Suppl 2:S94.
- Marin M, Güris D, Chaves SS, et al. Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2007; 56:1.
- Civen R, Lopez AS, Zhang J, et al. Varicella outbreak epidemiology in an active surveillance site, 1995-2005. J Infect Dis 2008; 197 Suppl 2:S114.
- Reynolds MA, Watson BM, Plott-Adams KK, et al. Epidemiology of varicella hospitalizations in the United States, 1995-2005. J Infect Dis 2008; 197 Suppl 2:S120.
- Zhou F, Harpaz R, Jumaan AO, et al. Impact of varicella vaccination on health care utilization. JAMA 2005; 294:797.
- Nguyen HQ, Jumaan AO, Seward JF. Decline in mortality due to varicella after implementation of varicella vaccination in the United States. N Engl J Med 2005; 352:450.
- Centers for Disease Control: Summary of Notifiable Diseases--United States. MMWR Morb Mortal Wkly Rep 2009; 56:1-94.
- Centers for Disease Control and Prevention (CDC). Varicella-related deaths among children--United States, 1997. MMWR Morb Mortal Wkly Rep 1998; 47:365.
- Meyer PA, Seward JF, Jumaan AO, Wharton M. Varicella mortality: trends before vaccine licensure in the United States, 1970-1994. J Infect Dis 2000; 182:383.
- EPIDEMIOLOGY OF VARICELLA PRIOR TO VACCINE
- Incidence of varicella
- Varicella-related hospitalizations and mortality
- EPIDEMIOLOGY OF DISEASE AFTER INTRODUCTION OF VARICELLA VACCINE
- Incidence of infection
- Varicella-related hospitalizations
- Overall mortality
- - Childhood mortality
- - Adult mortality
- FUTURE CONCERNS
- SUMMARY AND RECOMMENDATIONS