Maximum chance of infection in dialysis is by-

Grafts and catheters are associated with much higher rates of Infection than fistulas Intravenous catheters are often used in patients with ARF or CRF. For patients on maintenance hemodialysis, tunneled catheters(2 seperate catheters or single with 2 lumen) are often used when Av fistula and grafts are not feasible due to anatomical considerations. Tunneled catheters are tunneled under the skin, tunnel reduces bacterial translocation from the skin, so there is lower rate of infection with tunneled catheters than with non tunneled temporary catheters. Most tunneled catheters are placed in Internal jugular vein Other veins used are external jugular, femoral ,subclan(subclan stenosis is a frequent complication ) Ref:Harrison 20th edition pg no. 2123