title: Changes in Neisseria meningitidis disease epidemiology in the United States, 1998-2007: implications for prevention of meningococcal disease.
abstract: BACKGROUND
  In January 2005, a quadrivalent (serogroups A, C , Y, and W-135) meningococcal conjugate vaccine was licensed for use in adolescents. This report describes the epidemiologic features of meningococcal disease in the United States from January 1998 through December 2007, before and during implementation of adolescent quadrivalent meningococcal conjugate vaccination.
  
  
  METHODS
  Data were collected from active surveillance for invasive Neisseria meningitidis conducted through the Active Bacterial Core surveillance (ABCs) sites during 1998-2007. Isolates from cases were serogrouped at the ABCs site and confirmed at the Centers for Disease Control and Prevention. Estimates of the incidence and number of cases in the 50 states were calculated, standardizing for race and age group.
  
  
  RESULTS
  In the period 1998-2007, a total of 2262 cases of meningococcal disease were reported from ABCs sites; 11.3% of these cases were fatal. The estimated United States average annual incidence of meningococcal disease was 0.53 cases per 100,000 population (95% confidence interval, 0.51-0.55), and an estimated 1525 (95% confidence interval, 1470-1598) cases occurred annually. The annual incidence decreased 64.1%, from 0.92 cases per 100,000 population in 1998 to 0.33 cases per 100,000 population in 2007. Infants aged <1 year have the highest incidence of meningococcal disease (5.38 cases per 100,000 population). After introduction of the quadrivalent meningococcal conjugate vaccine, no significant decrease in serogroup C or Y meningococcal disease was seen among those aged 11-19 years in 2006-2007, compared with 2004-2005.
  
  
  CONCLUSIONS
  Before the introduction of the quadrivalent meningococcal conjugate vaccine, the incidence of meningococcal disease in the United States decreased to a historic low. However, meningococcal disease still causes a substantial burden of disease among all age groups. Future vaccination strategies may include targeting infants and preventing serogroup B meningococcal disease.
authors.affiliation: Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta Georgia 30333, USA. acohn@cdc.gov
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Cohn
authors.forename: Jessica R
authors.initials: JR
authors.lastname: MacNeil
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
authors.forename: Cynthia
authors.initials: C
authors.lastname: Hatcher
authors.forename: Jordan
authors.initials: J
authors.lastname: Theodore
authors.forename: Mark
authors.initials: M
authors.lastname: Schmidt
authors.forename: Tracy
authors.initials: T
authors.lastname: Pondo
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Arnold
authors.forename: Joan
authors.initials: J
authors.lastname: Baumbach
authors.forename: Nancy
authors.initials: N
authors.lastname: Bennett
authors.forename: Allen S
authors.initials: AS
authors.lastname: Craig
authors.forename: Monica
authors.initials: M
authors.lastname: Farley
authors.forename: Ken
authors.initials: K
authors.lastname: Gershman
authors.forename: Susan
authors.initials: S
authors.lastname: Petit
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
authors.forename: Arthur
authors.initials: A
authors.lastname: Reingold
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Shutt
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Zell
authors.forename: Leonard W
authors.initials: LW
authors.lastname: Mayer
authors.forename: Thomas
authors.initials: T
authors.lastname: Clark
authors.forename: David
authors.initials: D
authors.lastname: Stephens
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Messonnier
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000517:prevention & control*; D008875:Middle Aged; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult