title: Prevention of antibiotic-nonsusceptible Streptococcus pneumoniae with conjugate vaccines.
abstract: BACKGROUND
  Streptococcus pneumoniae (pneumococcus) caused approximately 44000 US invasive pneumococcal disease (IPD) cases in 2008. Antibiotic nonsusceptibility complicates IPD treatment. Using penicillin susceptibility breakpoints adopted in 2008, we evaluated antibiotic-nonsusceptible IPD trends in light of the introductions of a 7-valent pneumococcal conjugate vaccine (PCV7) in 2000 and a 13-valent pneumococcal conjugate vaccine (PCV13) in 2010.
  
  
  METHODS
  IPD cases were defined by isolation of pneumococcus from a normally sterile site in individuals residing in Active Bacterial Core surveillance (ABCs) areas during 1998-2008. Pneumococci were serotyped and tested for antibiotic susceptibility using broth microdilution.
  
  
  RESULTS
  During 1998-2008, ABCs identified 43198 IPD cases. Penicillin-nonsusceptible strains caused 6%-14% of IPD cases, depending on age. Between 1998-1999 and 2008, penicillin-nonsusceptible IPD rates declined 64% for children aged <5 years (12.1-4.4 cases per 100000), and 45% for adults aged ≥65 (4.8-2.6 cases per 100000). Rates of IPD nonsusceptible to multiple antibiotics mirrored these trends. During 2007-2008, serotypes in PCV13 but not PCV7 caused 78%-97% of penicillin-nonsusceptible IPD, depending on age.
  
  
  CONCLUSIONS
  Antibiotic-nonsusceptible IPD rates remain below pre-PCV7 rates for children <5 and adults ≥65 years old. PCV13 vaccines hold promise for further nonsusceptibility reductions.
authors.affiliation: Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, Georgia 30329, USA. lhampton@cdc.gov
authors.forename: Lee M
authors.initials: LM
authors.lastname: Hampton
authors.forename: Monica M
authors.initials: MM
authors.lastname: Farley
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.forename: Ann
authors.initials: A
authors.lastname: Thomas
authors.forename: Arthur
authors.initials: A
authors.lastname: Reingold
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Bennett
authors.forename: Susan
authors.initials: S
authors.lastname: Petit
authors.forename: Kenneth
authors.initials: K
authors.lastname: Gershman
authors.forename: Joan
authors.initials: J
authors.lastname: Baumbach
authors.forename: Bernard
authors.initials: B
authors.lastname: Beall
authors.forename: James
authors.initials: J
authors.lastname: Jorgensen
authors.forename: Anita
authors.initials: A
authors.lastname: Glennen
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Zell
authors.forename: Matthew
authors.initials: M
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D015995:Prevalence; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000276:immunology* / Q000302:isolation & purification; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: C538862:13-valent pneumococcal vaccine; D000900:Anti-Bacterial Agents; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines