Epidemiology and outcome of nosocomial and community-onset bloodstream infection.

We performed a prospective study of bloodstream infection to determine factors independently associated with mortality. Between February 1999 and July 2000, 929 consecutive episodes of bloodstream infection at two tertiary care centers were studied. An ICD-9-based Charlson Index was used to adjust for underlying illness. Crude mortality was 24% (14% for community-onset versus 34% for nosocomial bloodstream infections). Mortality attributed to the bloodstream infection was 17% overall (10% for community-onset versus 23% for nosocomial bloodstream infections). Multivariate logistic regression revealed the independent associations with in-hospital mortality to be as follows: nosocomial acquisition (odds ratio [OR] 2.6, P < 0.0001), hypotension (OR 2.6, P < 0.0001), absence of a febrile response (P = 0.003), tachypnea (OR 1.9, P = 0.001), leukopenia or leukocytosis (total white blood cell count of <4500 or >20000, P = 0.003), presence of a central venous catheter (OR 2.0, P = 0.0002), and presence of anaerobic organism (OR 2.5, P = 0.04). Even after adjustments were made for underlying illness and length of stay, nosocomial status of bloodstream infection was strongly associated with increased total hospital charges (P < 0.0001). Although accounting for about half of all bloodstream infections, nosocomial bloodstream infections account for most of the mortality and costs associated with bloodstream infection.