title: Invasive pneumococcal disease in infants younger than 90 days before and after introduction of PCV7.
abstract: BACKGROUND
  Introduction of the heptavalent pneumococcal conjugate vaccine (PCV7) changed the epidemiology of invasive pneumococcal disease (IPD). We evaluated the changes that occurred after PCV7 introduction among Utah infants aged 1 to 90 days, too young to be fully immunized.
  
  
  METHODS
  We identified children <18 years with culture-confirmed IPD from 1997-2010. We analyzed demographic, clinical, and serotype data for infants aged 1-90 days. The pre- and post-vaccine introduction periods spanned 1997-2000 and 2001-2010, respectively.
  
  
  RESULTS
  Of 513 children with IPD, 36 were 1 to 90 days and accounted for 7% of IPD cases in both the pre- and post-vaccine introduction period. The pre-vaccine IPD incidence rate was 5.0 per 100 000 live births, and was unchanged in the post-vaccine introduction period. IPD caused by PCV7 serotypes decreased by 74% (from 2.2 to 0.58 per 100 000), whereas non-vaccine serotype IPD increased by 57% (from 2.8 to 4.4 per 100 000). Sixteen infants (44%) required intensive care, and 3 (8%) died. Bacteremia without focus (56%) and meningitis (44%) were the predominant syndromes in the pre- and post-vaccine introduction periods, respectively. In the post-vaccine introduction period, serotype 7F was the most common serotype among infants and was responsible for 50% of meningitis.
  
  
  CONCLUSIONS
  The incidence of IPD in Utah infants aged 1 to 90 days caused by PCV7 serotypes decreased after PCV7 introduction, but overall incidence was unchanged. In the post-vaccine introduction period, serotype 7F predominated in this age group and was associated with meningitis.
authors.affiliation: Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, UT, USA.
authors.forename: Liset
authors.initials: L
authors.lastname: Olarte
authors.forename: Krow
authors.initials: K
authors.lastname: Ampofo
authors.forename: Chris
authors.initials: C
authors.lastname: Stockmann
authors.forename: Edward O
authors.initials: EO
authors.lastname: Mason
authors.forename: Judy A
authors.initials: JA
authors.lastname: Daly
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Pavia
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Byington
mesh_terms: D016470:Bacteremia / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control; D003422:Critical Care; D003430:Cross-Sectional Studies; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008586:Meningitis, Pneumococcal / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000276:immunology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000276:immunology; D014589:Utah
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial; C053135:pneumococcal polysaccharide, type 7
keywords: Streptococcus pneumoniae; infant; invasive pneumococcal disease; pneumococcal conjugate vaccine