title: Patient characteristics but not virulence factors discriminate between asymptomatic and symptomatic E. coli bacteriuria in the hospital.
abstract: BACKGROUND
  Escherichia coli is a common cause of asymptomatic and symptomatic bacteriuria in hospitalized patients. Asymptomatic bacteriuria (ASB) is frequently treated with antibiotics without a clear indication. Our goal was to determine patient and pathogen factors suggestive of ASB.
  
  
  METHODS
  We conducted a 12-month prospective cohort study of adult inpatients with E. coli bacteriuria seen at a tertiary care hospital in St. Louis, Missouri, USA. Urine cultures were taken at the discretion of treating physicians. Bacterial isolates were tested for 14 putative virulence genes using high-throughput dot-blot hybridization.
  
  
  RESULTS
  The median age of the 287 study patients was 65 (19-101) years; 78% were female. Seventy percent had community-acquired bacteriuria. One-hundred ten (38.3%) patients had ASB and 177 (61.7%) had symptomatic urinary tract infection (sUTI). Asymptomatic patients were more likely than symptomatic patients to have congestive heart failure (p = 0.03), a history of myocardial infarction (p = 0.01), chronic pulmonary disease (p = 0.045), peripheral vascular disease (p = 0.04), and dementia (p = 0.03). Patients with sUTI were more likely to be neutropenic at the time of bacteriuria (p = 0.046). Chronic pulmonary disease [OR 2.1 (95% CI 1.04, 4.1)] and dementia [OR 2.4 (95% CI 1.02, 5.8)] were independent predictors for asymptomatic bacteriuria. Absence of pyuria was not predictive of ASB. None of the individual virulence genes tested were associated with ASB nor was the total number of genes.
  
  
  CONCLUSIONS
  Asymptomatic E. coli bacteriuria in hospitalized patients was frequent and more common in patients with dementia and chronic pulmonary disease. Bacterial virulence factors could not discriminate symptomatic from asymptomatic bacteriurias. Asymptomatic E. coli bacteriuria cannot be predicted by virulence screening.
authors.affiliation: Division of Infectious Diseases, Washington University School of Medicine, St, Louis, MO 63110, USA. jmarscha@dom.wustl.edu
authors.forename: Jonas
authors.initials: J
authors.lastname: Marschall
authors.forename: Marilyn L
authors.initials: ML
authors.lastname: Piccirillo
authors.forename: Betsy
authors.initials: B
authors.lastname: Foxman
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhang
authors.forename: David K
authors.initials: DK
authors.lastname: Warren
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Henderson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058345:Asymptomatic Infections / Q000453:epidemiology*; D001437:Bacteriuria / Q000453:epidemiology / Q000382:microbiology* / Q000652:urine; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology* / Q000652:urine; D029968:Escherichia coli Proteins / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; D037521:Virulence Factors