Dialysis catheter infection related peritonitis: incidence and time dependent risk

The aim of this study was to conduct an in-depth analysis of the relationship of exit site and tunnel infection (ES/TI) to peritonitis and catheter loss in peritoneal dialysis patients, with emphasis on the incidence and risk of infection over time. Bacterial epidemiologies of 63 consecutively implanted catheters were studied for a combined total of 1,248 dialysis months. Analyses of bacterial profiles, infection rates, probabilities of time to first infection, and catheter survival were performed. The probability of first ES/TI and peritonitis was greatest during the first postimplant year. The earlier in dialysis history that patients developed an infection, the more infection prone they continued to be during the course of their dialysis experience. Staphylococcus aureus was the predominant organism for both ES/TI and peritonitis. The incidence of S. aureus infection was greatest during the first year and decreased over time on dialysis. S. aureus ES/TI caused significant risk for subsequent development of peritonitis, and 93% of ES/TI related peritonitis episodes were caused by this organism. Half of all ES/TIs that led to related peritonitis occurred by 3.5 months, and 100% by 12.8 months postimplant. S. aureus ES/TI related peritonitis led to catheter loss in 85% of cases. Our study identified a high risk period for infection for as long as 12 months postimplant. The inherent characteristics of ES/TI related peritonitis suggest that prevention should focus on both the organism and time period at risk. These findings are important in considering issues regarding S. aureus prophylaxis regimens versus nasal carrier treatment protocols.