[O415] Magnitude of bacteraemia predicts one-year mortality

K. Gradel, H. Schønheyder, M. Søgaard, C. Dethlefsen, H. Nielsen. (
Aalborg, DK)

Objectives: All hospitals in our region use the BacT/Alert® blood culture (BC) system with a 3-bottle BC set for adults. We hypothesised that the magnitude of bacteraemia (i.e., number of positive bottles in the initial BC set) predicts one-year mortality. Methods: In a population-based study we analysed all patients with monomicrobial bacteraemia in North Jutland County, Denmark, 1996–2004. Data from the County Bacteraemia Registry were linked to the Hospital Discharge Registry (comorbidity) and the Danish Civil Registration System (vital status, including date of emigration or death). Patients with a BC index of 1 (i.e., one positive bottle) were chosen as the reference group. We computed Kaplan–Meier curves and performed Cox regression analyses to estimate mortality rate ratios (MRRs) with 95% confidence intervals [CIs] 30 and 365 days after the initial BC sampling date, first in crude analyses, second in analyses adjusted for age, comorbidity, acquisition of infection (community, nosocomial, or healthcare-related), and incident or recurrent episode. In addition we stratified the analyses on acquisition of infection and pathogen group. Results: A total of 6,955 patients had 8,152 episodes of monomicrobial bacteraemia, among which one-year follow-up was possible for 8,108 (99.5%). Of these, 2,539, 1,511 and 4,058 episodes had a BC index of 1, 2 and 3, respectively. In crude analyses, 30-day MRRs were 0.98 [0.851.14] and 1.20 [1.071.34] for BC indices 2 and 3, respectively, and similar MRRs were found after 1 year (0.99 [0.891.09] and 1.12 [1.041.21]). All estimates remained unchanged in the adjusted analyses. Results for community-acquired and healthcare-related bacteraemia episodes were consistent with the non-stratified results, whereas all MRRs for nosocomial infections were close to 1. A BC index of 3 had the strongest long-term prognostic impact in pneumococcal bacteraemia (n = 855) (adjusted MRR 1.60 [1.092.34]).Conclusions: In patients with community-acquired or healthcare-related bacteraemia, high magnitude of bacteraemia (i.e., a BC index of 3) predicted increased 30-day as well as 365-day mortality.

Session Info: Community-acquired bacterial infection II
Session Type: Oral presentations


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