Chlorine inactivation of human norovirus, murine norovirus and poliovirus in drinking water

Aims: To evaluate the reduction of human norovirus (HuNoV) by chlorine disinfection under typical drinking water treatment conditions. Methods and Results: HuNoV, murine norovirus (MNV) and poliovirus type 1 (PV1) were inoculated into treated water before chlorination, collected from a drinking water treatment plant, and bench-scale free chlorine disinfection experiments were performed for two initial free chlorine concentrations, 0 center dot 1 and 0 center dot 5 mg l-1. Inactivation of MNV reached more than 4 log(10) after 120 and 0 center dot 5 min contact time to chlorine at the initial free chlorine concentrations of 0 center dot 1 and 0 center dot 5 mg l-1, respectively. Conclusions: MNV was inactivated faster than PV1, and there was no significant difference in the viral RNA reduction rate between HuNoV and MNV. The results suggest that appropriate water treatment process with chlorination can manage the risk of HuNoV infection via drinking water supply systems. Significance and Impact of the Study: The data obtained in this study would be useful for assessing or managing the risk of HuNoV infections from drinking water exposure.