Microbial quality and public health risks of filtered drinking water served in restaurants: A case study from the Dhaka division of Bangladesh

Considering the ongoing drinking water crisis, a small-scale study was conducted to evaluate the microbial quality of filtered water commonly served in restaurants across the Dhaka division of Bangladesh. This research focused on samples collected from restaurants in Manikganj, Savar, and Dhaka city of Bangladesh to assess the hygiene standards of this widely consumed water. A total of 15 water samples were analyzed, including five from each location. The findings revealed that 11 samples, four from Manikganj, four from Savar, and three from Dhaka contained both total and fecal coliforms. Conversely, only four samples, consisting of one from Manikganj, one from Savar, and two from Dhaka, were found free of these contaminants. The detection of coliforms highlights the potential risk of contamination with pathogenic microorganisms. Additionally, most of the samples exceeded the acceptable limits for total heterotrophic count as prescribed by the World Health Organization (WHO) and the Bangladesh Standards and Testing Institution (BSTI). Biochemical analysis suggested the possible presence of pathogens such as Shigella, Salmonella, Enterobacter, and Klebsiella species. Although typically offered at an affordable price of BDT 1 or 2 in most restaurants, this filtered water does not meet the microbiological standards for safe drinking. It is imperative that supply companies undergo rigorous inspections to enforce quality control measures. Furthermore, restaurant practices require scrutiny, including the hygiene standards of workers and the cleanliness of water supply systems. Contamination risks may also arise from the glasses used to serve water, which can become tainted if washed with untreated water from restaurant supplies.