Abstract
Background Patients undergoing maintenance hemodialysis (HD) are exposed to large volumes of treated water, making its microbiological quality crucial for patient safety. Contaminated dialysis water can introduce microbial pathogens into the bloodstream, increasing the risk of pyrogenic reactions, sepsis, and chronic inflammation. Water quality monitoring remains a challenge in many healthcare settings despite its importance. This study evaluates the microbiological quality of treated water and dialysate used in a tertiary care hospital dialysis unit in Imphal, India. Methods This observational study was conducted at the Regional Institute of Medical Sciences, Imphal, from August 2021 to January 2025. A total of 84 water samples were collected from different points in the dialysis system, including product water, storage water, middle port water, and return water. Samples were processed using membrane filtration and analyzed for microbial contamination using culture-based methods and Vitek 2 Compact for species identification. The findings were assessed against the Association for the Advancement of Medical Instrumentation (AAMI) standards for dialysis water quality. Results Microbiological analysis revealed varying contamination levels across different water sources. Product water exhibited the highest microbial presence, with Acinetobacter species being the most frequently detected organism. The most recent sample (January 2025) showed Aeromonas spp. and Acinetobacter spp. in product water. Some samples exceeded AAMI standards, with colony-forming unit (CFU) counts ranging from 104 to 274 CFU/100 mL in product water. Storage, middle port, and return water showed lower contamination levels. Out of the total 21 samples collected, unsatisfactory microbial growth was observed in three samples of product water and one sample of storage water as per AAMI standard, whereas no unsatisfactory growth was detected in any of the middle port water or return water samples. Acinetobacter baumannii was detected in all four water types, while other multidrug-resistant organisms, such as Klebsiella pneumoniae, were found in return water. Conclusion The study highlights fluctuating levels of microbial contamination in dialysis water, with Acinetobacter species being the predominant contaminant. Regular monitoring, stringent adherence to water treatment protocols, and strict infection control measures are essential to ensure dialysis water safety and improve patient outcomes.