Follow-up blood cultures within 48 hours of initiating antimicrobial therapy should be obtained in the following circumstances:
Bacteremia due to Staphylococcus aureus
Known or suspected endocarditis
Presence of fever, leukocytosis, or other signs of infection more than 72 hours following initiation of antimicrobial therapy
Known or suspected site of infection with limited antimicrobial penetration (such as an abscess or joint space infection)
Presence of intravascular prosthetic devices
Multi-drug resistant organism(s)
Unknown source of initial bacteremia
