**4.1. HD-related bacteremia**

One of the factors that increase the risk of developing IE in HD patients is bacteremia, which are exposed to repetitive vascular access through an arteriovenous fistula (AVF), polytetrafluoroethylene (PTFE) grafts or percutaneous catheters for HD, or cuffed or noncuffed dual lumen catheter.

The incidence of bacteremia is related to vascular access type, ranging from 1.6 to 7.7 per 1000 days with percutaneous catheters and 0.2 to 0.5 per 1000 days with AVF, according to the reference.

The use of catheters during HD is the leading cause of bacteremia in HD patients [4, 8, 15, 18].

A hierarchy of bacteremia risk exists among various types of HD vascular access; it is less common in patients with native arteriovenous fistulae, while synthetic grafts, cuffed catheters, and uncuffed catheters yield a progressively increasing risk.

These episodes of bacteremia during HD are relatively common. They can be endogenous or exogenous: through the microorganism flora found in the patient (endogenous) or through the pathogen from another source such as might occur through hands or contaminated instruments (exogenous) [5].

There are three points where the pathogens can enter the bloodstream (BS):
