[Effect of nosocomial bacteremia caused by oxacillin-resistant Staphylococcus aureus on mortality and length of hospitalization].

OBJECTIVES

To identify the attributed mortality rate of bloodstream hospital infection by Staphylococcus aureus resistant to methicillin (MRSA) and its effect on length of hospital stay.

DESIGN

Case-control study.

SETTING

Hospital São Paulo da Universidade Federal de São Paulo, a 660-bed, tertiary-care teaching hospital in São Paulo, Brazil.

PATIENTS

Seventy one adults patients with hospital-acquired MRSA bacteremia diagnosed between January 1, 1991, and September 30, 1992, and 71 MRSA-free controls were matched by the following criteria: age, sex, underlying disease, surgical procedure, same risk time and admission date.

RESULTS

The incidence of patients with hospital sepsis by MRSA accounted for 73.22% of the patients with hospital bloodstream infection by Staphylococcus aureus. The mortality rate of the cases was 56.33 (40/71) and 11.26 (8/71) of the controls. The attributable mortality rate was 45.07% (OR = 17.0; IC 95% = 3.58-202.26; p = 0.000001). The length of hospital stay median time was of 32.55 days for the cases and 29.75 for the controls (p = 0.32).

CONCLUSION

A high level of sepsis by MRSA was observed in all the Staphylococcus aureus bacteremia. The bloodstream hospital infection by MRSA itself does provide a high level of mortality independently from the patients base disease, without however, increasing their hospital length of stay.