Central line (CL):A central line is an intravascular access device or catheter that terminates at or close to the heart, or in one of the great vessels. The line may be used for infusion of intravenous fluids and drugs, or for haemodynamic monitoring. Central line (CL) infection can be local (e.g. phlebitis) or systemic.

Catheter-related bloodstream infection (CRBSI) is bloodstream infection (BSI) attributed to an intravascular catheter by quantitative culture of the catheter tip or by differences in growth between catheter and peripheral venipuncture blood culture specimens. This definition is primarily used in research. The BSI should not be related to an infection at another site.

Central Line-Associated Bloodstream Infections (CLABSI) is defined as a laboratory-confirmed BSI where an eligible BSI organism (see case definition of BSI) is identified, and an eligible central line is present on the day/ day before the event.

Eligible Central Line: A CL that has been in place for more than two consecutive calendar days, following the first access of the central line, in an inpatient location, during the current admission. Such lines are eligible for CLABSI events and remain eligible for CLABSI events until the day after removal from the body or patient discharge, whichever comes first.