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.