Epidemiology and outcome of primary and secondary community-acquired bacteraemia in adult patients

Abstract number: 1733_450

Ortega M., Almela M., Martínez J., Marco F., Soriano A., López J., Sánchez M., Muñoz A., Mensa J.

Objectives: To know the associated factors and outcome of community-acquired primary bacteraemia (PB); to describe the most frequently isolated microorganisms, its antibiotic resistance pattern and to guide the most adequate antibiotic treatment.

Patients and Methods: 1640 community-acquired bacteraemias in non-neutropenic adults were consecutively enrolled from January 2003 to May 2006 and prospectively followed up. Non-conditional logistic regression methods were used with PB and death as dependent variables.

Results: 1440 were secondary bacteraemia (SB) and 200 (12%) were PB. The independent factors associated with PB were: male gender (OR: 1.69, 95%CI: 1.27–2.25, p = 0.001), ultimately or rapidly fatal prognosis of underlying disease (OR: 2.48, 95%CI: 1.84–3.34, p = 0.001) and incorrect empirical antibiotic therapy (OR: 2.33, 95%CI: 1.61–3.33, p = 0.001). The most frequently isolated microorganisms in PB were E. coli and other enterobacterias (26% and 22%) and S. aureus (15%). There were 28% and 37% of ciprofloxacin resistant E. coli strains in SB and PB, respectively (p = 0.2). Mortality was significantly higher in PB cases (13% vs 8%, p = 0.04). The independent factors associated with mortality in PB were: ultimately or rapidly fatal prognosis of underlying disease (OR: 2.1, 95%CI: 1.41–3.13, p = 0.001) lack of fever at the moment of bacteraemia (OR: 2.38, 95%CI: 1.18–4.76, p = 0.02) and incorrect empirical antibiotic therapy (OR: 2.01, 95%CI: 1.22–3.33, p = 0.006).

Conclusions: The initial empiric antibiotic treatment is more frequently incorrect in PB than in SB and this is a predictor factor for mortality in PB. The resistance pattern of E. coli, other enterobacterias and S. aureus in every setting should guide the most appropriated empirical treatment for PB.