Source of infection and other factors associated with case fatality in community-acquired bacteremia - A Danish population-based cohort study from 1992 to 1997

Abstract

Objective. To examine the association between the source of infection, other factors and the 30-day case-fatality rate (CFR) in patients with community-acquired bacteremia. Methods. We included in the study 1844 patients older than 15 years (median age 72 years) with a first episode of community-acquired bacteremia in the period 1992-97 from a population-based bacteremia database. Information on co-morbidity, antibiotic prescriptions and date of death was obtained from health registries through linkage with the patient's personal identification number. The outcome measure was the overall CFR. Results. The mean CFR was 18% (20% in 1992-95, 15% in 1996-97). The commonest sources of infection were the urinary tract (29%) and the respiratory tract (20%); patients with an undetermined source accounted for 21% in 1992-95 and 13% in 1996-97. The most frequent bacteria were Escherichia coli (33%) and Streptococcus pneumoniae (22%). Thirty-two per cent of patients did not receive appropriate empirical antibiotic therapy. The following factors were associated with CFR: source of infection other than the urinary tract, first four years of the study, age ≥75 years, and presence of co-morbidity. An undetermined source showed the strongest association with CFR during the period 1996-97. Conclusions. As an undetermined source of infection was strongly associated with CFR, physicians should be aware of the significance of identifying and eliminating a source of infection, and more efforts should be directed at timely and appropriate empirical antibiotic therapy.