General Principles

• Bloodstream infections (BSIs) are a major cause of morbidity and mortality despite available antimicrobials and supportive care.
• Community-acquired BSI is defined by positive blood cultures obtained in the outpatient setting or <48 hours into the patient’s hospital stay.
• Transient bacteremia can occur with brushing teeth, dental work, or other mucosal disrupting procedures, but it is typically asymptomatic and self-limiting.
• Positive blood cultures resulting from contamination by skin or environmental flora do not represent true infection and should be assessed based on clinical presentation.
• S. aureus, S. epidermidis (coagulase-negative staphylococci), aerobic gram-negative species, and Candida spp. are the most common organisms associated with BSI and catheter-related bloodstream infections (CRBSI).