Objective To explore the current status of microbial contamination in drinking water in Hubei province, China, investigate the factors affecting microbial indicators, and provide basic data for the next step of drinking water contamination prevention and assessment.

Methods This study analyzed the mornitoring results of microbial indicators (including total coliforms, thermotolerant coliforms, Escherichia coli, and total colony) in the urban and rural drinking water monitoring projects in Hubei province from 2018 to 2022. Multivariate logistic regression was used to analyze the factors influencing the qualified rate of microbial indicators.

Results From 2018 to 2022, 33 384 water samples from centralized water supply projects in Hubei province were monitored, with the qualified rate of total count being 91.04%, the qualified rate of total coliforms being 90.11%, the qualified rate of thermotolerant coliforms/Escherichia coli being 94.41%, and the average qualified rate of microbial indicators being 85.68%, increasing year by year(χ_trend²=264.83, P < 0.001).Multivariate logistic regression showed that rural drinking water (odds ratio OR=10.31, 95% confidence interval CI: 9.02-11.78), the absence of disinfection (OR=2.37, 95% CI: 1.96-2.87), surface water (OR=1.20, 95% CI: 1.09-1.32), tap water (OR=1.18, 95% CI: 1.10-1.26), and flood season (OR=1.11, 95% CI: 1.04-1.18) were risk factors affecting the unqualification of microbial indicators in drinking water samples.

Conclusion The qualified rates of microbial indicators of drinking water in Hubei province have been improved during the five years. However, fecal contamination indicators, such as thermotolerant coliforms and E. coli, were still detected. Future efforts should focus on monitoring microbial contamination in rural drinking water, enhancing drinking water disinfection management.