- Staphylococcus aureus (S.aureus) bacteremia (SAB) can be either a community or a healthcare associated infection and is associated with 50% risk of morbidity and mortality
- S. aureus is never considered a bloodstream contaminant: isolation of S.aureus from > 1 venous or arterial blood culture samples collected from a symptomatic patient should always be considered clinically significant
- Management of SAB by Infectious Diseases service has been shown to improve outcomes
- Mandatory ID consult at HHS and SJHH (HHS – please refer to policy titled Mandatory Infectious Diseases Consult for Staphylococcus aureus bacteremia and fungemia in the policy library)
Assessment and Management
- Clinical assessment: identify source, extent and presence of septic complications of infection
- Source control: elimination and/or debridement of sites of infection (e.g. remove central lines, debride soft tissue infection). Follow-up blood cultures q48 hours after start of appropriate treatment until clearance of S.aureus is documented
- Echocardiography (TEE preferred especially if high index of suspicion for endocarditis, prosthetic valve or pacemaker present)
Antibiotic Treatment – Target Therapy Once Susceptibilities Are Available
If MRSA Risk is Low
Cloxacillin 2 g IV q4-6h or Cefazolin 2 g IV q8h
If MRSA Risk is Moderate or the Patient is Severely Ill
Vancomycin 25 mg/kg IV load can be considered in severely ill patients then 15mg/kg IV q12h (frequency will depend on renal function but target trough between 10-15 ug/mL) ADD cloxacillin 2 g IV q4-6h or cefazolin 2 g IV q8h
If Known MRSA
Vancomycin 25mg/kg IV load can be considered in severely ill patients then 15mg/kg IV q12h (frequency will depend on renal function but target trough between 10-15 ug/mL).
No benefit for addition of rifampin or gentamicin for uncomplicated bacteremia or native valve endocarditis
Duration
- 2 weeks from last positive blood culture if no endocarditis or deep tissue infection, prompt clinical response AND repeat blood cultures negative within 72 hours
- 4-6 weeks if endocarditis or deep tissue infection or slow to clear bacteremia
- Intravenous treatment for the entire treatment duration is highly recommended