Microbial and Endotoxin Contamination in Water and Dialysate in the Central United States

Abstract

The purified water supplies and randomly selected dialysates of 51 chronic and acute dialysis centers in the central United States were surveyed to assess the relative risks to dialysis patients from microbial and endotoxin contamination. A culture medium more sensitive than those generally employed in routine quality assurance assays was used for recovery of bacteria from water. With this medium, 35.3% of the water samples and 19% of the dialysate samples were out of compliance with the Association for the Advancement of Medical Instrumentation (AAMI) standards: 200 and 2,000 colony forming units (CFU)/ml, respectively. There was no correlation observed between the type of water purification system or the frequency of disinfection of the system and the bacterial and endotoxin contamination levels. There was also no correlation found between the bacterial and fungal CFU per ml and the endotoxin concentration per ml (EU/ ml). It is recommended that more sensitive culturing methods be used to provide adequate bacterial monitoring of dialysate center water supplies. Dialysis centers should monitor endotoxin in dialysate on a regular schedule and immediately after any endotoxemic‐like patient reactions. Yeast and fungi were observed in 10% and 64% of the water systems, respectively. Dialysate was contaminated by yeast and fungi in 30% and 70% of the centers, respectively. The concentrations of these microbes in both fluids were much lower than bacteria. However, they were observed often enough to warrant further investigation of their impact on the well‐being of dialysis patients.

Development, validation and applications of the monocyte activation test for pyrogens based on human whole blood

“…Studies in Germany (Bambauer et al, 1994), Greece (Arvanitidou et al, 1998), the USA (Klein et al, 1990), and Canada (laurence and lapierre, 1995) revealed that even these moderate standards are not met, which is even more critical considering that a patient with chronic renal failure receives up to 400 l of dialysis fluid a week. Next to Gram-negative bacteria, cocci (micrococci, staphylococci, and streptococci) were found in the dialysate of 83, 70, and 10% of the centers, respectively, indicating the importance of Gram-positive contaminations.…”

“…Since then, contaminations have been found in the pure water (Klein et al, 1990;Pegues et al, 1992;Kulander et al, 1993;Bambauer et al, 1994), the machines, especially to areas with low circulation or dead spaces, which serve as a reservoir for bacteria (Phillips et al, 1994), filter materials (Schouten et al, 2000), and bicarbonate concentrates (Pegues et al, 1992).…”

Worldwide water standards for hemodialysis

“…Endotoxin testing reveals nothing about the levels of other microbiological contaminants, including yeasts, fungi, peptidoglycans, and fragments of bacterial DNA, all of which have been identified in water used for hemodialysis. [25][26][27]…”

“…All of these arguments are predicated on the assumption that endotoxin levels are an adequate measure of water quality. Endotoxin testing reveals nothing about the levels of other microbiological contaminants, including yeasts, fungi, peptidoglycans, and fragments of bacterial DNA, all of which have been identified in water used for hemodialysis 25–27 …”

Worldwide Guidelines for the Preparation and Quality Management of Dialysis Fluid and Their Implementation

“…Surveys of dialysis fluid quality from the late 1980s show that many dialysis facilities did not comply with applicable standards for microbiological quality [4,5] . Changes in compliance since that time can be difficult to assess because of differences in how standards are implemented.…”