title: Population antibiotic susceptibility for Streptococcus pneumoniae and treatment outcomes in common respiratory tract infections.
abstract: OBJECTIVE
  Antibiotic-resistant Streptococcus pneumoniae potentially threatens the successful treatment of common respiratory tract infections (RTIs); however, the relationship between antibiotic resistance and treatment outcomes remains unclear. We aimed to test the hypothesis that higher in vitro penicillin and erythromycin nonsusceptibility levels among clinical isolates of S. pneumoniae are associated with higher risk of treatment failure in suppurative acute otitis media (AOM), acute sinusitis, and acute exacerbation of chronic bronchitis (AECB).
  
  
  METHODS
  We conducted a population-level analysis using treatment outcomes data from a national, managed-care claims database, and antibiotic susceptibility data from a national repository of antimicrobial susceptibility results between 1997 and 2000. Treatment outcomes in patients with suppurative AOM, acute sinusitis, or AECB receiving selected macrolides or beta-lactams were assessed. Associations between RTI-specific treatment outcomes and antibiotic nonsusceptibility were determined using Spearman correlation coefficients with condition-specific paired outcome and susceptibility data for each region and each year.
  
  
  RESULTS
  There were 649 552 available RTI outcomes and 7252 susceptibility tests performed on S. pneumoniae isolates. There were no statistically significant trends across time for resolution proportions following treatment by either beta-lactams or macrolides among any of the RTIs. Correlation analyses found no statistically significant association between S. pneumoniae susceptibility and RTI treatment outcomes apart from a significant positive association between of erythromycin nonsusceptibility in ear isolates and macrolide treatment resolution for suppurative AOM.
  
  
  CONCLUSIONS
  On the population level, in vitro S. pneumoniae nonsusceptibility to macrolide or beta-lactam antibiotics was not associated with treatment failure in conditions of probable S. pneumoniae etiology.
authors.affiliation: Department of Epidemiology and Preventive Medicine, University of Maryland, School of Medicine, Baltimore, MD 21201, USA.
authors.forename: Jon P
authors.initials: JP
authors.lastname: Furuno
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Metlay
authors.forename: James P
authors.initials: JP
authors.lastname: Harnett
authors.forename: Jerome
authors.initials: J
authors.lastname: Wilson
authors.forename: Patricia
authors.initials: P
authors.lastname: Langenberg
authors.forename: Jessina C
authors.initials: JC
authors.lastname: McGregor
authors.forename: Jingkun
authors.initials: J
authors.lastname: Zhu
authors.forename: Eli N
authors.initials: EN
authors.lastname: Perencevich
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D029481:Bronchitis, Chronic / Q000188:drug therapy / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D018942:Macrolides / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D010035:Otitis Media, Suppurative / Q000188:drug therapy / Q000382:microbiology; D012141:Respiratory Tract Infections / Q000188:drug therapy* / Q000382:microbiology; D012852:Sinusitis / Q000188:drug therapy / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects*; D016896:Treatment Outcome; D047090:beta-Lactams / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D047090:beta-Lactams