Type of infection	Criteria
Catheter colonisation	A significant growth of a micro‐organism (> 15 CFU) from the catheter tip, subcutaneous segment or catheter hub in the absence of clinical signs of infection
Exit‐site/insertion site infection	Microbiologically documented: exudates at catheter exit site yield a micro‐organism with or without concomitant bloodstream infection. Clinically documented: erythema or induration within 2 cm of the catheter insertion site in the absence of associated bloodstream infection and without concomitant purulence
Positive blood culture	Micro‐organism, potentially pathogenic, cultured from one or more blood culture
Bloodstream infection	Positive blood culture with a clinical sepsis (see below)
Primary bloodstream infection	Laboratory‐confirmed bloodstream infection or clinical sepsis occurring without documented infection
Secondary bloodstream infection	Laboratory‐confirmed bloodstream infection secondary to another documented infection
Clinical sepsis	Requires one of the following with no other recognised cause: fever (> 38° C), hypotension (SBP < 90 mmHg), oliguria (< 20 ml/h); and all of the following: blood culture not performed or no organism detected in blood, no apparent infection at another body site and clinical response to therapy following catheter removal or change
Catheter‐associated bloodstream infection	Primary bloodstream infection or clinical sepsis in the presence of an intravascular device
Catheter‐related bloodstream infection	Laboratory‐confirmed bloodstream infection in the presence of an intravascular access: at least 1 positive blood culture obtained from a peripheral vein, clinical manifestation of infection and no apparent source of the bloodstream infection except the vascular access, and with 1 of the microbiological methods: a positive result of semi‐quantitative (> 15 CFUs per catheter segment) or quantitative culture (> 103 CFU/catheter segment) with the same organism, paired quantitative blood cultures with a > 5:1 ratio device versus peripheral, differential time to positivity (blood culture obtained from a CVC is positive at least 2 h earlier than a peripheral blood culture)
CFU: colony‐forming units; CVC: central venous catheter; S BP: systolic blood pressure.