title: Validity of reported varicella history as a marker for varicella zoster virus immunity among unvaccinated children, adolescents, and young adults in the post-vaccine licensure era.
abstract: OBJECTIVE
  We assessed the validity of reported varicella history as a marker for varicella zoster virus immunity among unvaccinated persons 1 to 29 years of age, and we examined varicella disease characteristics associated with varicella zoster virus immunity among those reporting positive histories.
  
  
  METHODS
  We conducted a cross-sectional study at 7 community-based sites in Philadelphia, Pennsylvania, between June 2004 and May 2006 and recruited 1476 participants 1 to 29 years of age who had not been vaccinated against varicella. Sensitivity, specificity, and positive predictive value were determined by comparing self-reported or parent-reported varicella histories from a standardized study interview with varicella zoster virus immunoglobulin G serological results for each participant. We performed multivariate logistic regression analyses to determine which disease characteristics best predicted seropositivity.
  
  
  RESULTS
  The sensitivity of reported varicella history was highest (81%-89%) among participants > or =10 years of age, whereas specificity was highest among participants 1 to 4 years of age (99%) and > or =20 years (88%). Reported varicella history was highly predictive of seropositivity (>95%) only among participants > or =15 years of age. For participants 10 to 14 years of age, parental reports of a generalized itchy rash with 1 of the following were highly predictive of seropositivity: varicella transmission to another household member or being raised in a household with no other children. Among participants < or =9 years of age, no combination of disease characteristics was both highly predictive of seropositivity and common.
  
  
  CONCLUSIONS
  The validity of reported varicella history varies according to age, and a reported history is no longer highly predictive of seropositivity among cohorts born since 1994 (participants < or =9 years of age). Universal varicella vaccination, regardless of history, for these children should be considered, as should simplified criteria for varicella zoster virus immunity among unvaccinated persons born before 1994.
authors.affiliation: Varicella Active Surveillance Project, Division of Disease Control, Philadelphia Department of Public Health, Philadelphia, PA 19146, USA. dana.perella@phila.gov
authors.forename: Dana
authors.initials: D
authors.lastname: Perella
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Fiks
authors.forename: Aisha
authors.initials: A
authors.lastname: Jumaan
authors.forename: Donovan
authors.initials: D
authors.lastname: Robinson
authors.forename: Paul
authors.initials: P
authors.lastname: Gargiullo
authors.forename: Jonathan
authors.initials: J
authors.lastname: Pletcher
authors.forename: Christine M
authors.initials: CM
authors.lastname: Forke
authors.forename: D Scott
authors.initials: DS
authors.lastname: Schmid
authors.forename: Mia
authors.initials: M
authors.lastname: Renwick
authors.forename: Foram
authors.initials: F
authors.lastname: Mankodi
authors.forename: Barbara
authors.initials: B
authors.lastname: Watson
authors.forename: C Victor
authors.initials: CV
authors.lastname: Spain
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D002644:Chickenpox / Q000453:epidemiology / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D007109:Immunity; D007074:Immunoglobulin G / Q000276:immunology; D007223:Infant; D015143:Philadelphia / Q000453:epidemiology; D011159:Population Surveillance; D012650:Self Disclosure; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G