Bacteriological Assessment of Dialysis Water and Fluid at a Renal Unit in Nnewi, Anambra State

The microbiological safety of water and dialysate fluid used in haemodialysis is critically important, as patients with end-stage renal disease are highly immunocompromised and are exposed to large volumes of dialysis fluid during each treatment session. This study assessed the bacteriological quality of dialysis water and fluid at the renal unit of Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Anambra State, South East Nigeria. Water samples were collected from product water and dialysate points monthly over six months. Testing was conducted per the Association for the Advancement of Medical Instrumentation (AAMI) standards, with total viable counts by pour plate method and endotoxin quantification by LAL kinetic turbidimetric assay. Isolates from out-of-specification samples were characterized biochemically and by susceptibility testing. Results revealed that 25 percent of product water samples exceeded the AAMI bacterial count limit of 100 CFU/mL. Endotoxin levels exceeded the AAMI limit of 0.25 EU/mL in 16.7 percent of dialysate samples. Pseudomonas species and non-tuberculous Mycobacteria were the most frequently identified contaminants. Failure was associated with breaches in membrane filter integrity and infrequent disinfection of water treatment equipment. These findings highlight serious patient safety vulnerabilities in the study facility and call for mandatory microbiological monitoring of dialysis water with documented corrective action protocols. Keywords: dialysis water, haemodialysis, endotoxins, Pseudomonas, renal unit.