Guidelines
S. aureus Bacteremia

S. aureus Bacteremia

Diagnosis

  • Presence of Methicillin Sensitive Staphylococcus aureus (MSSA) or Methicillin Resistant Staphylococcus aureus (MRSA) in blood
  • Bacteremia can be secondary to a primary S. aureus infection elsewhere such as skin and soft tissue, bone and joint, pneumonia or vascular catheter
  • S. aureus bacteremia can also result in subsequent seeding and infection of a sterile site such as heart valves or prosthetic devices
  • It is imperative to look for sources and metastatic sites of infection in the setting of S. aureus bacteremia

Thorough clinical assessment should be performed to identify potential sources and metastatic sites of infection, for example:

  • Infective endocarditis (IE)
  • Cardiac device infection
  • Osteomyelitis
  • Septic arthritis
  • Prosthetic joint infection
  • Meningitis
  • Pneumonia
  • Soft tissue infection
  • Vascular-catheter related infection

Blood cultures should be drawn 48h after initial positive cultures and as needed thereafter until clearance is demonstrated

Definitions

Positive blood cultures AND the following:

  • Exclusion of endocarditis via echocardiogram
  • No implanted prosthesis (i.e. prosthetic heart valves or vascular grafts)
  • Follow-up cultures performed on specimens obtained 2-4 days after initiating IV therapy and source control do not grow S. aureus
  • Defervescence within 72 hours of initiating effective therapy (IV antistaphylococcal therapy and removal of presumed focus of infection (i.e. debridement of soft tissue infection or IV catheter removal)
  • No evidence of metastatic sites of infection

Positive blood cultures AND the following:

  • Infective endocarditis

  • Implanted prosthesis

  • Follow up cultures performed on specimens obtained 24 days after initial set that grow MRSA

  • Persistent fevers within 72 hours of initiating effective therapy

  • Evidence of metastatic sites of infection

Treatment

  • Drainage of abscess (if present)
  • Removal of seeded devices (i.e. vascular catheters, prosthetic material, or orthopedic hardware)

Additional Information