[Community-acquired bacteremia]

Abstract

Bacteremia continues to be one of the main causes of mortality despite the existence of numerous antimicrobial agents and an increase in means of support. A variety of factors, such as the type of microorganism, age, the underlying disease and where the bacteremia was acquired, can change the prognosis of the infection. The aim of this study was to analyze the cases of community-acquired bacteremia gathered prospectively from the Basurto hospital in Bilbao, Spain. The incidence of bacteremia was estimated using preestablished protocol (SEPSIS-DATA) from January 1994 to September 2001. Information was gathered on all the cases of bacteremia at the hospital and only those which were of non-hospital origin (2886 cases) were selected for the study. In our hospital, 67.82% of the bacteremia cases were community-acquired, a figure which remained stable throughout the 8-year study period. A total of 54.64% of the patients were male, 1603 (55.54%) of whom were over age 60 years. The most common underlying diseases were diabetes (15.75%), neoplasia (14.96%) and HIV infection (12.9%). The majority of the cases (2216, 76.8%) were admitted to the general medicine ward, 335 (11.6%) to surgery, 200 (6.9%) to pediatrics and 135 (4.67%) to ICU. The origin of the bacteremia was urinary (33%), gastrointestinal (18%) or respiratory (18.26%). The most common microorganisms were E. coli (36%), S. pneumoniae (13%), S. aureus (9.46%), S. enteritidis (2.87%), P. aeruginosa (2.71%), P. mirabilis (2.65%) and N. meningitidis (2.45%). The bacteremia was polymicrobial in 6.27% of the cases. The most used antibiotics were ceftriaxone (31%), gentamicin (7.3%) and amoxicillin-clavulanic acid (6.9%). Overall mortality was 13.82%. The relative frequency of community-acquired/nosocomial infection remained stable in two-thirds of the total cases. The incidence of bacteremia decreased in the 20-40 year age group and in those with HIV infection. E. coli and S. pneumoniae increased, while S. aureus decreased. The use of imipenem and quinolones increased. E. coli resistance to quinolones increased from 3.54% in 1995 to 14.36% in 2000. Mortality decreased slightly, with no significant differences.