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Background Persistent Staphylococcus aureus bacteremia (SAB) is defined based on varying duration in literature. The primary objective was to determine the risk of poor outcomes in relation to bacteremia duration. Methods Multicenter, prospective, observational study of adult hospitalized patients with SAB. Medical records were reviewed for pertinent data. Patients were grouped by bacteremia duration: short (1–2 days), intermediate (3–6 days), and prolonged (≥7 days) and compared for risk factors and outcomes. Results Of 884 patients, 63% had short, 28% intermediate, and 9% prolonged bacteremia. Overall mean age was 57 years, and 70% were male. The prolonged group had the highest proportion of methicillin-resistant SAB (P <.0001). Choice of antibiotic therapy did not significantly affect bacteremia duration; however, time to source-control procedure was delayed in the prolonged and intermediate groups compared with the short group (3.5 vs 3 vs 1 day, P <.0001). Metastatic complications, length of stay, and 30-day mortality were progressively worse as bacteremia duration increased (P <.0001). Every continued day of bacteremia was associated with a relative risk of death of 1.16 (95% confidence interval, 1.10–1.22; P <.0001), with a significant increase in risk starting at 3 days as determined by receiver operating characteristic analysis. Conclusions Optimal management of SAB should target bacterial clearance as soon as possible to minimize incremental risk of mortality with each day of positive blood culture. Delay in source control but not type of antistaphylococcal therapy was significantly associated with prolonged bacteremia and worse outcomes. [ABSTRACT FROM AUTHOR]

Commercially available lipid formulations of amphotericin B (Abelcet, Amphotec, and AmBisome) represent a significant advance in drug delivery technology. Differences in biochemical, pharmacokinetic, and pharmacodynamic properties among the lipid products have been shown in in vitro and in vivo models. Clinical experience with these products has been primarily in patients either refractory to or intolerant of conventional amphotericin B deoxycholate (AmBd). None of the lipid-based products demonstrates superior efficacy when prospectively compared with AmBd in the treatment of documented infections. When used for the empirical treatment of febrile neutropenia, AmBisome significantly reduced the incidence of proven emergent fungal infections but did not improve short-term survival rates, in comparison with AmBd. Acute infusion-related adverse events vary, whereas nephrotoxicity is reduced with all three lipid formulations. Until superior efficacy is clearly shown (for documented infections) or pharmacoeconomic analyses document the value of these drugs, use of such expensive agents should be highly restricted to those who are intolerant of or refractory to AmBd. [ABSTRACT FROM PUBLISHER]