title: Molecular epidemiology of pediatric pneumococcal empyema from 2001 to 2007 in Utah.
abstract: Utah had a high rate of pediatric pneumococcal empyema (PPE) prior to licensure of the pneumococcal conjugate vaccine (PCV-7) in 2000. The majority (62%) of PPE cases was due to nonvaccine serotypes, primarily Streptococcus pneumoniae serotype 1, multilocus sequence type (MLST) 227. PPE in Utah children has increased over the last decade. It is unclear whether the increase was due to serotype replacement or switch. In this study, we describe the incidence and molecular epidemiology of PPE by MLST in Utah children after the licensure of PCV-7. Empyema rates increased from 8.5/100,000 children in the state of Utah in 2001 to 12.5/100,000 children in 2007 (P = 0.006). Ninety-eight percent was due to nonvaccine serotypes (P < 0.001 when compared to the pre-PCV-7 period). PPE was primarily due to serotypes 1, 3, 19A, and 7F, with MLST demonstrating sequence types (ST) that were commonly present in the United States prior to licensure of PCV-7. Serotype switch was not documented. Replacement disease with common ST of serotypes 1,3, 7F, and 19A rather than serotype switch was responsible for the increase in PPE in Utah children.
authors.affiliation: Department of Pediatrics, University of Utah, 295 Chipeta Way, Salt Lake City, UT 84108, USA. Carrie.byington@hsc.utah.edu
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Byington
authors.forename: Kristina G
authors.initials: KG
authors.lastname: Hulten
authors.forename: Krow
authors.initials: K
authors.lastname: Ampofo
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Sheng
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Pavia
authors.forename: Anne J
authors.initials: AJ
authors.lastname: Blaschke
authors.forename: Melinda
authors.initials: M
authors.lastname: Pettigrew
authors.forename: Kent
authors.initials: K
authors.lastname: Korgenski
authors.forename: Judy
authors.initials: J
authors.lastname: Daly
authors.forename: Edward O
authors.initials: EO
authors.lastname: Mason
mesh_terms: D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004653:Empyema / Q000453:epidemiology* / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D015994:Incidence; D017720:Molecular Epidemiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000276:immunology; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D014589:Utah / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial; D022242:Pneumococcal Vaccines