Methods: This retrospective cohort study included patients admitted to 121 hospitals from 2003 to 2010. Patients were included if they had a blood culture positive for MSSA and received definitive therapy with cefazolin, nafcillin, or oxacillin. Definitive therapy was the receipt of an antimicrobial between 4 to 14 days after the first positive blood culture was collected. Cox proportional hazard regression and ordinal logistic regression (categories: no recurrence, recurrence, death) were used to examine the association between treatment and mortality or recurrence. Recurrent MSSA bloodstream infections were defined as a MSSA positive blood culture between 45 to 365 days after the first MSSA positive blood culture.
Results: Of 3,303 patients, 2,033 (62%) patients received definitive therapy with PSP. Patients who received cefazolin had a 26% lower 30-day mortality compared to patients who received PSP (Hazard ratios (HR): 0.74; 95% Confidence Intervals (CI): 0.60-0.91) after controlling for severity of illness, comorbidity score, age, skin and soft tissue infections, osteomyelitis, and endocarditis. However, 90-day mortality (HR: 0.93; 95% CI: 0.80-1.09) and the odds of recurrence (Odds Ratio: 1.10; 95% CI: 0.91-1.31) were similar among patients who received cefazolin compared with patients who received PSP, after controlling for those factors.
Conclusion: In this large, multi-center study, outcomes (90-day mortality and recurrence) were similar among patients receiving cefazolin compared with patients receiving PSP for MSSA infections complicated by bacteremia. Given similar outcomes and convenient dosing, physicians might consider cefazolin for MSSA bloodstream infections.
E. Perencevich, Cubist Pharmaceuticals, inc: Grant Investigator , Research grant
M. Ohl, None
M. Goto, None
D. Livorsi, None
M. Jones, None
J. Albertson, None
R. Nair, None
A. O'shea, None
M. Schweizer, None