title: Impact of the Pneumococcal Conjugate Vaccine and Antibiotic Use on Nasopharyngeal Colonization by Antibiotic Nonsusceptible Streptococcus pneumoniae, Alaska, 2000[FIGURE DASH]2010.
abstract: BACKGROUND
  We describe the relative impact of the heptavalent pneumococcal conjugate vaccine (PCV7, introduced 2001) and antibiotic use on colonization by antibiotic-resistant pneumococci in urban Alaskan children during 2000-2010.
  
  
  METHODS
  We obtained nasopharyngeal swab specimens from a convenience sample of children aged <5 years at clinics annually during 2000-2004 and 2008-2010. PCV7 status and antibiotic use <90 days before enrollment were determined by interview/medical records review. Pneumococci were characterized by serotype and susceptibility to penicillin (PCN). Isolates with full PCN resistance (PCN-R) or intermediate PCN resistance (PCN-I) were classified as PCN-NS.
  
  
  RESULTS
  We recruited 3496 children (median, 452 per year). During 2000-2010, a range of 18-29% per year of children used PCN/amoxicillin (P value for trend = 0.09); the proportion age-appropriately vaccinated with PCV7 increased (0[FIGURE DASH]90%; P < 0.01). Among pneumococcal isolates, the PCV7-serotype proportion decreased (53-<1%; P < 0.01) and non[FIGURE DASH]PCV7-serotype proportion increased (43-95%; P < 0.01). PCN-R pneumococcal colonization prevalence decreased (23-9%; P < 0.01) and PCN-I pneumococcal colonization prevalence increased (13-24%; P < 0.01); overall PCN-NS pneumococcal colonization prevalence was unchanged. PCN-NS among colonizing PCV7-type and non[FIGURE DASH]PCV7-type pneumococci remained unchanged; a mean of 31% per year of PCV7-type and 10% per year of non[FIGURE DASH]PCV7-type isolates were PCN-R, and 10% per year of PCV7 and 20% per year of non[FIGURE DASH]PCV7-type isolates were PCN-I.
  
  
  CONCLUSIONS
  Overall, PCN-NS pneumococcal colonization remained unchanged during 2000-2010 because increased colonization by predominantly PCN-I non-PCV7 serotypes offset decreased colonization by predominantly PCN-R PCV7 serotypes. Proportion PCN-NS did not increase within colonizing pneumococcal serotype groups (PCV7 vs. non-PCV7) despite stable PCN use in our population.
authors.affiliation: From the *Arctic Investigations Program, Division of Preparedness and Emerging Infections, National Center for Emerging and Zoonotic Infectious Disease, US Centers for Disease Control and Prevention (CDC), Anchorage, Alaska; and †Alaska Native Tribal Health Consortium, Anchorage, Alaska.
authors.forename: Prabhu P
authors.initials: PP
authors.lastname: Gounder
authors.forename: Melissa
authors.initials: M
authors.lastname: Brewster
authors.forename: Michael G
authors.initials: MG
authors.lastname: Bruce
authors.forename: Dana J T
authors.initials: DJ
authors.lastname: Bruden
authors.forename: Karen
authors.initials: K
authors.lastname: Rudolph
authors.forename: Debby A
authors.initials: DA
authors.lastname: Hurlburt
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Hennessy
mesh_terms: D000413:Alaska / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009305:Nasopharynx / Q000382:microbiology*; D010406:Penicillins / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D014611:Vaccination / Q000706:statistics & numerical data; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D010406:Penicillins; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate