Nosocomial Bacteremia in a Community Hospital: a 20-Year Prospective Study

Objectives To evaluate the characteristics and prognostic factors of nosocomial bacteremia (NB) in adult patients. Methods During a 20-year period (1983–2002) all episodes of NB were studied in a 320-bed community hospital. Clinical and laboratory features of survivors and non-survivors were compared using the SPSS statistical packet. Results 728 episodes of NB occurred in 687 patients (57% males, 43% females) aged 65±18 yr. The length of the hospital stay until the NB was 19±16 days. Malignancy (30%), diabetes (24%), chronic renal failure (13%), and liver cirrhosis (9%) were the main underlying conditions. These were rapidly or ultimately fatal in 43%. The most frequent sources of NB were: intravascular catheters (23%), urinary tract (21%), intraabdominal (14%), respiratory tract (12%), skin and soft tissues (9%). The most frequent isolates were: Escherichia coli (165), Staphylococcus aureus (110), coagulase-negative staphylococci (99), Pseudomonas spp (94), Klebsiella spp (53), Enterococcus spp (49), Bacteroides spp (47), Proteus spp (30), and S. pneumoniae (29). Crude mortality was 30% and mortality related to bacteremia was 20%. In the multivariate analysis nine variables were identified as independently associated with mortality: septic shock (OR: 4.9; 95%CI: 3.0–8.0), rapidly fatal underlying disease (OR: 6.4; 95%CI: 2.3–17.4), axillary temperature 65 yr (OR: 2.3; 95%CI: 1.4–3.5), inappropriate antibiotic therapy (OR: 2.2; 95%CI: 1.3–3.4), previous corticosteroid therapy (OR: 2.2; 95%CI: 1.3–3.5), respiratory, gastrointestinal or unknown origin (OR: 2.2; 95%CI: 1.4–3.2), and infection due to a high risk organism ( Bacteroides, Pseudomonas or S. aureus ) (OR: 1.6; 95%CI: 1.1–2.4). While in the first decade of the study the urinary tract was the main source of NB and E. coli was the predominant microorganism, in the second decade the intravascular catheters constituted the main source and coagulase-negative staphylococci were the predominant microorganisms. Conclusions 1) The main sources of NB were: intravascular catheters, the urinary tract and intraabdominal. 2) E. coli, S. aureus , coagulase-negative staphylococci, and Pseudomonas spp were the predominant causative organisms. 3) Nine variables were significantly related with mortality.