Incidence, risk factors, and outcomes of Klebsiella pneumoniae bacteremia.
BACKGROUND
Although Klebsiella pneumoniae is the second most common cause of Gram-negative bloodstream infections, its epidemiology has not been defined in a nonselected population. We sought to describe the incidence of, risk factors for, and outcomes associated with K. pneumoniae bacteremia.


METHODS
Population-based surveillance for K. pneumoniae bacteremia was conducted in the Calgary Health Region (population 1.2 million) from 2000 to 2007.


RESULTS
A total of 640 episodes of K. pneumoniae bacteremia were identified for an overall annual population incidence of 7.1 per 100,000; 174 (27%) were nosocomial, 276 (43%) were healthcare-associated community onset, and 190 (30%) were community acquired. Elderly patients and men were at highest risk for K. pneumoniae bacteremia. Dialysis, solid-organ transplantation, chronic liver disease, and cancer were the most important risk factors for acquiring K. pneumoniae bacteremia. Rates of resistance to trimethoprim/sulfamethoxazole increased significantly during 2000 to 2007. The case fatality rate was 20%, and the annual population mortality rate was 1.3 per 100,000. Increasing age, nosocomial acquisition, non-urinary and non-biliary focus of infection, and several comorbid illnesses were independently associated with an increased risk of death.


CONCLUSIONS
This is the first population-based study to document the major burden of illness associated with K. pneumoniae bacteremia and identifies groups at increased risk of acquiring and dying of these infections.
Meatherall
Bonnie L
BL
Department of Medicine, University of Calgary and Calgary Laboratory Services, Calgary, Alberta, Canada.
Gregson
Daniel
D
Ross
Terry
T
Pitout
Johann D D
JD
Laupland
Kevin B
KB
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007710:Klebsiella Infections / Q000453:epidemiology*; D007711:Klebsiella pneumoniae; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult