title: Contribution of host, bacterial factors and antibiotic treatment to mortality in adult patients with bacteraemic pneumococcal pneumonia.
abstract: BACKGROUND
  Host and bacterial factors as well as different treatment regimens are likely to influence the outcome in patients with bacteraemic pneumococcal pneumonia.
  
  
  OBJECTIVE
  To estimate the relative contribution of host factors as well as bacterial factors and antibiotic treatment to mortality in bacteraemic pneumococcal pneumonia.
  
  
  METHODS
  A cohort study of 1580 adult patients with community-acquired bacteraemic pneumococcal pneumonia was conducted between 2007 and 2009 in Sweden. Data on host factors and initial antibiotic treatment were collected from patient records. Antibiotic resistance and serotype were determined for bacterial isolates. Logistic regression analyses were performed to assess risk factors for 30-day mortality.
  
  
  RESULTS
  Smoking, alcohol abuse, solid tumour, liver disease and renal disease attributed to 14.9%, 13.1%, 13.1%, 8.0% and 7.4% of the mortality, respectively. Age was the strongest predictor, and mortality increased exponentially from 1.3% in patients <45 years of age to 26.1% in patients aged ≥85 years. There was considerable confounding by host factors on the association between serotype and mortality. Increasing age, liver disease and serotype were associated with mortality in patients admitted to the ICU. Combined treatment with β-lactam antibiotics and macrolide/quinolone was associated with reduced mortality in patients in the ICU, although confounding could not be ruled out.
  
  
  CONCLUSIONS
  Host factors appear to be more important than the specific serotype as determinants of mortality in patients with bacteraemic pneumococcal pneumonia. Several host factors were identified that contribute to mortality, which is important for prognosis and to guide targeted prevention strategies.
authors: Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden. pontus.naucler@ki.se
authors: Pontus
authors: P
authors: Naucler
authors: Jessica
authors: J
authors: Darenberg
authors: Eva
authors: E
authors: Morfeldt
authors: Ake
authors: A
authors: Ortqvist
authors: Birgitta
authors: B
authors: Henriques Normark
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000942:Antigens, Bacterial / Q000276:immunology*; D016470:Bacteremia / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D011018:Pneumonia, Pneumococcal / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D011379:Prognosis; D012307:Risk Factors; D013296:Streptococcus pneumoniae / Q000276:immunology* / Q000302:isolation & purification; D015996:Survival Rate / Q000639:trends; D013548:Sweden / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial
keywords: Bacterial Infection; Clinical Epidemiology; Pneumonia; Respiratory Infection