title: Early Streptococcus pneumoniae serotype changes in Utah adults after the introduction of PCV13 in children.
abstract: BACKGROUND
  Pneumococcal conjugate vaccines (PCV) have indirect effects due to decreased Streptococcus pneumoniae colonization in vaccine recipients. We sought to determine whether the introduction of PCV13 in children led to changes in the epidemiology and clinical manifestations of invasive pneumococcal disease (IPD) in adults.
  
  
  METHODS
  We described demographics, comorbidities, clinical manifestations, and serotypes of IPD in Utah adults before (November 2009-February 2010) and after (March 2010-March 2012) the introduction of PCV13 in children. We also compare serotypes causing IPD in Utah adults and children.
  
  
  RESULTS
  After the introduction of PCV13 in the childhood vaccine program, the proportion of IPD due to PCV13 exclusive serotypes decreased significantly in Utah adults (64-40%, p=0.009), primarily due to a decline in serotype 7F (36-15%, p=0.008). There were non-significant increases in IPD due to Pneumococcal polysaccharide 23 (PPV23) unique serotypes and non-vaccine serotypes, most notably serotype 22F. Changes in the proportions of vaccine and non-vaccine serotypes were similar in adults and children. Meningitis was more commonly due to non-vaccine serotypes relative to non-meningitis cases (47% vs. 18%, p=0.007). When stratified by sex, decreases in PCV13 serotype IPD were only noted in men (76-33%, p=0.001).
  
  
  CONCLUSIONS
  Serotype epidemiology of IPD in adults closely follows that of children in the PCV13 era. Continued surveillance is needed to confirm whether replacement serotypes will lead to increases in pneumococcal meningitis and whether there are sex differences in the indirect effects of PCV vaccination in children.
authors.affiliation: Departments of Medicine and Pathology, University of Utah, Salt Lake City, UT, USA. Electronic address: augustkendall@gmail.com.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Kendall
authors.affiliation: Departments of Medicine and Pathology, University of Utah, Salt Lake City, UT, USA; Department of Infectious Diseases, Intermountain Healthcare, Murray, UT, USA.
authors.forename: Kristin K
authors.initials: KK
authors.lastname: Dascomb
authors.affiliation: Department of Infectious Diseases, Intermountain Healthcare, Murray, UT, USA.
authors.forename: Rajesh R
authors.initials: RR
authors.lastname: Mehta
authors.affiliation: Department of pediatrics, University of Utah, Salt Lake City, UT, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Stockmann
authors.affiliation: Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Edward O
authors.initials: EO
authors.lastname: Mason
authors.affiliation: Department of pediatrics, University of Utah, Salt Lake City, UT, USA.
authors.forename: Krow
authors.initials: K
authors.lastname: Ampofo
authors.affiliation: Department of pediatrics, University of Utah, Salt Lake City, UT, USA.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Pavia
authors.affiliation: Department of pediatrics, University of Utah, Salt Lake City, UT, USA.
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Byington
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D017589:Immunization Programs; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification*; D014589:Utah / Q000453:epidemiology; D018074:Vaccines, Conjugate / Q000008:administration & dosage
chemical_list: C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Epidemiology; Invasive pneumococcal disease; Pneumococcal vaccines; Streptococcus pneumoniae