title: Epidemiology of invasive pneumococcal disease among high-risk adults since the introduction of pneumococcal conjugate vaccine for children.
abstract: BACKGROUND
  Certain chronic diseases increase risk for invasive pneumococcal disease (IPD) and are indications for receipt of 23-valent pneumococcal polysaccharide vaccine (PPV23). Since the pediatric introduction of 7-valent pneumococcal conjugate vaccine (PCV7) in 2000, incidence of IPD among adults has declined. The relative magnitude of these indirect effects among persons with and without PPV23 indications is unknown.
  
  
  METHODS
  We evaluated IPD incidence among adults with and without PPV23 indications using population- and laboratory-based data collected during 1998-2009 and estimates of the denominator populations with PPV23 indications from the National Health Interview Survey. We compared rates before and after PCV7 use by age, race, PPV23 indication, and serotype.
  
  
  RESULTS
  The proportion of adult IPD cases with PPV23 indications increased from 51% before to 61% after PCV7 introduction (P < .0001). PCV7-serotype IPD declined among all race, age, and PPV23 indication strata, ranging from 82% to 97%. Overall IPD rates declined in most strata, by up to 65%. However, incidence remained highest among adults with PPV23 indications compared with those without (34.9 vs 8.8 cases per 100 000 population, respectively). Apart from age ≥65 years, diabetes is now the most common indication for PPV23 (20% of all cases vs 10% of cases in 1998-1999).
  
  
  CONCLUSIONS
  Although IPD rates have declined among adults, adults with underlying conditions remain at increased risk of IPD and comprise a larger proportion of adult IPD cases in 2009 compared with 2000. A continued increase in the prevalence of diabetes among US adults could lead to increased burden of pneumococcal disease.
authors.affiliation: Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Riyadh D
authors.initials: RD
authors.lastname: Muhammad
authors.forename: Reena
authors.initials: R
authors.lastname: Oza-Frank
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Zell
authors.forename: Ruth
authors.initials: R
authors.lastname: Link-Gelles
authors.forename: K M Venkat
authors.initials: KM
authors.lastname: Narayan
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.forename: Ann
authors.initials: A
authors.lastname: Thomas
authors.forename: Catherine
authors.initials: C
authors.lastname: Lexau
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Bennett
authors.forename: Monica M
authors.initials: MM
authors.lastname: Farley
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
authors.forename: Arthur
authors.initials: A
authors.lastname: Reingold
authors.forename: James
authors.initials: J
authors.lastname: Hadler
authors.forename: Bernard
authors.initials: B
authors.lastname: Beall
authors.forename: Keith P
authors.initials: KP
authors.lastname: Klugman
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Moore
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D006801:Humans; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000276:immunology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D012307:Risk Factors; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: C414006:23-valent pneumococcal capsular polysaccharide vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate