Abstract � Fiscal Year 2003

Abstract: Chickenpox is caused by the varicella zoster virus. After a person recovers from chickenpox, the virus lies dormant in sensory ganglia. The virus may reactivate usually at age 50 years and older, causing Herpes Zoster (HZ) or shingles, characterized by a painful vesicular rash. HZ may lead to post herpetic neuralgia, bacterial infection of lesions, pneumonia, encephalitis, and hemorrhagic complications, and has considerably higher morbidity than chickenpox.

Since varicella vaccinations for infants and children began in 1996, there has been a 70 to 80 percent decline in chickenpox cases. Studies suggest that exposure to persons with chickenpox can protect adults against reactivation of dormant virus and subsequent HZ episodes, presumably through immune boosting. Thus it is argued that the decline in chickenpox will lead to an epidemic of HZ lasting several decades, and this has caused concern in other countries considering varicella vaccination.

A surveillance system is needed for early detection of increasing HZ rates. The Health Maintenance Organizations (HMOs) that currently participate in the Vaccine Safety Datalink (VSD) project offer an opportunity to implement HZ surveillance. These HMOs monitor the health care of approximately 4 million adults to detect adverse events following vaccinations. Medical diagnoses are recorded from inpatient, outpatient, and emergency department contacts with patients. If there is evidence of an increase in HZ, the results will help develop policy for protecting the large population of persons at risk for HZ. Currently, there is a clinical trial investigating varicella vaccine for prevention or reduction in severity of HZ among at risk populations.

Institution: Centers for Disease Control and Prevention

Date: July 2003

Return to Research Program Awards for Fiscal Year 2003

Welcome Center | What's New | Publications | Contact Us

CDC Home | Search | Health Topics A-Z

Last updated: July 16, 2003

URL: http://www.cdc.gov/od/nvpo/research/abn50.htm

Centers for Disease Control and Prevention
National Vaccine Program Office