Comparative analysis of a rapid detection method and conventional method to ensure microbial quality of drinking water

Objective: Drinking water analysis is an important quality monitor and forms an integral part of the infection control policy of every hospital. On an average daily basis, 1750 liters of drinking water are used by patients and hospital staff. Presence of contaminating microorganisms in drinking water should therefore be identified at the earliest and necessary action be taken in order to prevent outbreaks through contaminated water. This study was conducted to compare two methods for drinking water analysis and document benefits of the new method. Methods: This cross sectional study was conducted over a period of two years at a tertiary care hospital in Chennai. A newer rapid method of drinking water analysis was evaluated for two years from July 2017 to June 2019. Parallel testing with conventional multiple tube method was performed. All samples collected from various sources during the study period were subjected to parallel testing by multiple tube method (conventional method for most probable number) and presence absence method (new method). Results: The new commercial kit for drinking water analysis comprehensively detects all water borne bacterial pathogens associated with gastroenteritis within 18 hours. The major advantage is marked reduction in turnaround time by 54 hours. False positive/false negative results were not encountered compared to the standard conventional method. Conclusion: Safer, healthier and high quality of water is ensured for use at an earlier and cost effective as well as environment friendly system. There was marked reduction in turnaround time, cost of testing, manpower usage, reagent wastage, waste generation using the kit based presence absence method. The new commercial kit can effectively replace the conventional method as an effective screening tool for drinking water analysis.