title: Noninvasive Streptococcus pneumoniae serotypes recovered from hospitalized adult patients in the United States in 2009 to 2012.
abstract: This study was conducted to determine the serotype distribution and trends over time of Streptococcus pneumoniae strains associated with noninvasive infections among adult patients ≥18 years of age in the United States (2009 to 2012). A total of 2,927 S. pneumoniae isolates recovered from patients presenting with respiratory infections and obtained mainly (87.0%) from lower respiratory tract specimens (sputum) were included. The levels of the 7-valent pneumococcal conjugate vaccine (PCV7) serotypes remained stable over the 4-year study period (4.6% to 5.5%; P = 0.953). Overall, 13-valent pneumococcal conjugate vaccine (PCV13) serotypes were identified in 32.7% of samples, declining from 33.7% to 35.5% in 2009 to 2011 to 28.2% in 2012 (P = 0.007), with a significant decrease in the levels of serotypes 7F (P = 0.013) and 6A (P = 0.010). The levels of 19A remained constant (15.8% to 17.1%) during 2009 to 2011, dropping to 12.2% in 2012 (P = 0.089). The prevalence of serotypes associated with the 23-valent pneumococcal polysaccharide vaccine (PPSV23), but not PCV13, remained generally stable; however, the prevalence of serotypes 15B and 15C (15B/15C) increased from 2.7% to 6.3% (P = 0.010). The proportion of nonvaccine serotypes increased gradually during the study period (P = 0.044), particularly for serotype 35B (from 3.6% in 2009 to 8.2% in 2012; P = 0.001). Nonsusceptibility rates for penicillin (susceptible breakpoint, ≤2 μg/ml) and clindamycin against PCV7 serotypes decreased over the period. These results suggest the emergence of indirect effects following introduction of PCV13 for infants and young children; continued surveillance is needed to assess the burden of PCV13 serotypes in the adult population after the implementation of age-based recommendations in the United States.
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA rodrigo-mendes@jmilabs.com.
authors.forename: Rodrigo E
authors.initials: RE
authors.lastname: Mendes
authors.affiliation: Pfizer Inc., Specialty Care-Medicines Development Group, Collegeville, Pennsylvania, USA.
authors.forename: Rosalind C
authors.initials: RC
authors.lastname: Hollingsworth
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Costello
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
authors.affiliation: Pfizer Inc., Specialty Care-Medicines Development Group, Collegeville, Pennsylvania, USA.
authors.forename: Raul E
authors.initials: RE
authors.lastname: Isturiz
authors.affiliation: Pfizer Inc., Specialty Care-Medicines Development Group, Collegeville, Pennsylvania, USA.
authors.forename: Dial
authors.initials: D
authors.lastname: Hewlett
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Farrell
mesh_terms: D006761:Hospitals; D006801:Humans; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000276:immunology* / Q000302:isolation & purification*; D014481:United States; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D018074:Vaccines, Conjugate