title: Decreasing incidence rates of bacteremia: a 9-year population-based study.
abstract: BACKGROUND
  Numerous studies have shown that the incidence rate of bacteremia has been increasing over time. However, few studies have distinguished between community-acquired, healthcare-associated and nosocomial bacteremia.
  
  
  METHODS
  We conducted a population-based study among adults with first-time bacteremia in Funen County, Denmark, during 2000-2008 (N = 7786). We reported mean and annual incidence rates (per 100,000 person-years), overall and by place of acquisition. Trends were estimated using a Poisson regression model.
  
  
  RESULTS
  The overall incidence rate was 215.7, including 99.0 for community-acquired, 50.0 for healthcare-associated and 66.7 for nosocomial bacteremia. During 2000-2008, the overall incidence rate decreased by 23.3% from 254.1 to 198.8 (3.3% annually, p < .001), the incidence rate of community-acquired bacteremia decreased by 25.6% from 119.0 to 93.8 (3.7% annually, p < .001) and the incidence rate of nosocomial bacteremia decreased by 28.9% from 82.2 to 56.0 (4.2% annually, p < .001). The incidence rate of healthcare-associated bacteremia remained stable. The most common microorganisms were Escherichia coli (28.3%), Staphylococcus aureus (12.3%), coagulase-negative staphylococci (10.0%) and Streptococcus pneumoniae (9.1%). Regardless of place of acquisition, the proportion of bacteremias caused by enterococci increased (p < .05) and the proportion caused by coagulase-negative staphylococci decreased (p < .05).
  
  
  CONCLUSIONS
  The incidence rates of community-acquired and nosocomial bacteremia decreased substantially over time.
authors.affiliation: Department of Infectious Diseases, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark. Electronic address: stig.nielsen@rsyd.dk.
authors.forename: S L
authors.initials: SL
authors.lastname: Nielsen
authors.affiliation: Department of Infectious Diseases, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Pedersen
authors.affiliation: Department of Clinical Microbiology, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: T G
authors.initials: TG
authors.lastname: Jensen
authors.affiliation: Centre for National Clinical Databases, South, Odense University Hospital, Sdr. Boulevard 29, Odense C, Denmark; Research Unit of Clinical Epidemiology, Institute of Clinical Research, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
authors.forename: K O
authors.initials: KO
authors.lastname: Gradel
authors.affiliation: Department of Clinical Microbiology, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: H J
authors.initials: HJ
authors.lastname: Kolmos
authors.affiliation: Department of Emergency Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: A T
authors.initials: AT
authors.lastname: Lassen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: Bacteremia; Community-acquired; Cross infection; Epidemiology; Microbiology; Trends