title: Nosocomial bloodstream infections in a Finnish tertiary care hospital: a retrospective cohort study of 2175 episodes during the years 1999-2001 and 2005-2010.
abstract: BACKGROUND
  Nosocomial infections are major causes of morbidity in hospitalized patients.
  
  
  METHODS
  Retrospective laboratory-based surveillance during 1999-2001 and 2005-2010 identified 2175 cases of nosocomial bloodstream infections (BSIs) in Tampere University Hospital (TAUH), Finland.
  
  
  RESULTS
  Analysis revealed that 57% of BSIs were caused by a gram-positive organism, 27% by a gram-negative organism, 5% by a fungal organism, and 11% were polymicrobial. The most common cause of nosocomial BSI was coagulase-negative staphylococci (23%). Candida species caused 5% of the infections. The 7-day and 30-day case fatalities were 8% (161/2158) and 15% (313/2175), respectively, and were highest in BSIs caused by Candida albicans (22% and 44%) and Pseudomonas aeruginosa (17% and 25%). The median age of patients was 54 years in 1999-2001, 57 years in 2005-2007, and 60 years in 2008-2010 (p < 0.001). The median time from hospital admission to the onset of BSI was 11 days (quartiles 5-18 days). This period was shortest for Streptococcus agalactiae BSI and longest for Candida non-albicans fungemia (1 vs 19 days). The case fatality rate in nosocomial BSI decreased during the years studied: 7-day and 30-day case fatalities were 9% and 16% during 1999-2001, 8.5% and 16% during 2005-2007, and 5% and 12% during 2008-2010, respectively (p < 0.003 and p = 0.022, respectively).
  
  
  CONCLUSIONS
  Gram-positive infections predominate in nosocomial BSIs. The median age of patients with nosocomial BSI has risen during the study years. The case fatality associated with nosocomial BSI has decreased.
authors.affiliation: From the Department of Internal Medicine, Tampere University Hospital , Tampere.
authors.forename: Reetta
authors.initials: R
authors.lastname: Huttunen
authors.forename: Emilia
authors.initials: E
authors.lastname: Åttman
authors.forename: Janne
authors.initials: J
authors.lastname: Aittoniemi
authors.forename: Tuula
authors.initials: T
authors.lastname: Outinen
authors.forename: Jaana
authors.initials: J
authors.lastname: Syrjänen
authors.forename: Tommi
authors.initials: T
authors.lastname: Kärki
authors.forename: Outi
authors.initials: O
authors.lastname: Lyytikäinen
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000401:mortality*; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000401:mortality*; D005260:Female; D005387:Finland / Q000453:epidemiology; D016908:Gram-Positive Bacterial Infections / Q000401:mortality*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D055815:Young Adult
keywords: BSI; case fatality; health-care associated; incidence; nosocomial