title: Community-acquired pneumonia in North American emergency departments: drug resistance and treatment success with clarithromycin.
abstract: BACKGROUND
  Limited information on antibiotic resistance of Streptococcus pneumoniae (SP) exists for patients discharged from emergency departments with community-acquired pneumonia.
  
  
  OBJECTIVE
  Using a standardized collection process, this study examined sputum microbiology in outpatient community-acquired pneumonia.
  
  
  METHODS
  This was a multicenter, prospective cohort study conducted in North American emergency departments between December 2001 and May 2003. Thirty-one emergency departments enrolled patients older than 18 years with a Pneumonia Severity Index of I to III. All patients received oral clarithromycin and were followed up for four weeks. SP resistance to macrolides and penicillin was determined by a central laboratory.
  
  
  RESULTS
  Among the 317 cultured sputum samples, 116 (37%; 95% confidence interval [CI] = 32% to 42%) grew an identifiable organism; 74 (23% of cultured cases; 95% CI = 19% to 28%) grew non-SP organisms and 42 grew SP organisms (SP positive; 13% of cultured cases; 95% CI = 10% to 17%). A total of 13 resistant organisms (4% of cultured cases; 95% CI = 2% to 6%) were identified. Resistance to macrolides occurred in nine patients (3% of cultured cases [95% CI = 1% to 5%]; 24% of SP-positive cases [95% CI = 11% to 37%]); and resistance to penicillin occurred in nine patients (3% of all sputum-positive cases [95% CI = 1% to 5%]; 21% of SP-positive cases [95% CI = 9% to 34%]). The four-week cure rates were similar in both groups.
  
  
  CONCLUSIONS
  Among outpatients with community-acquired pneumonia, half produced adequate sputum samples and most were culture negative. SP resistance was similar to rates from large national databases, and results were of little (if any) consequence. In low-risk Pneumonia Severity Index cases, sputum cultures should not be collected routinely.
authors.affiliation: Department of Emergency Medicine, University of Alberta Hospital, Edmonton, Alberta, Canada. brian.rowe@ualberta.ca
authors.forename: Brian H
authors.initials: BH
authors.lastname: Rowe
authors.forename: Sam G
authors.initials: SG
authors.lastname: Campbell
authors.forename: Edwin D
authors.initials: ED
authors.lastname: Boudreaux
authors.forename: Ian
authors.initials: I
authors.lastname: Colman
authors.forename: Riyad B
authors.initials: RB
authors.lastname: Abu-Laban
authors.forename: Marco L A
authors.initials: ML
authors.lastname: Sivilotti
authors.forename: Sunday
authors.initials: S
authors.lastname: Clark
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017291:Clarithromycin / Q000627:therapeutic use*; D017714:Community-Acquired Infections; D024881:Drug Resistance, Bacterial; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009656:North America; D011014:Pneumonia / Q000188:drug therapy*; D011446:Prospective Studies; D013183:Sputum / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D017291:Clarithromycin