Long-Term Survival of Human Enteric Virus Surrogates (Murine Norovirus, Rhesus Rotavirus, and Porcine Sapovirus) in...

Enteric viruses are major causes of food- and waterborne diseases. Due to the limited cultivability of many human enteric viruses, surrogate viruses are commonly used to model their environmental persistence. This study aimed to evaluate the not-well-understood long-term survival of murine norovirus (MNV), rhesus rotavirus (RRV), and porcine sapovirus (PoSaV), used here as cultivable surrogate viruses for human enteric viruses, in bottled drinking water. Bottled water artificially inoculated with each virus was stored at 4 °C, 25 °C, and 37 °C for up to 365 days, and viral infectivity was quantified using TCID₅₀ and plaque assays, with the latter successfully applied for PoSaV quantification. The initial virus concentrations were 5.2 log₁₀ TCID₅₀/mL for MNV, 6.5 log₁₀ PFU/mL for RRV, and 4.0 log₁₀ PFU/mL for PoSaV. MNV and RRV remained infectious for at least one year at 4 °C, whereas PoSaV gradually declined and became undetectable by day 55. At 25 °C, the viral inactivation rate was accelerated: MNV became undetectable by day 160, RRV by day 320, and PoSaV by day 20. At 37 °C, a rapid inactivation rate was observed for all viruses, with MNV, RRV, and PoSaV becoming undetectable by days 20, 80, and 10, respectively. These results demonstrate the pronounced temperature-dependent survival of enteric viruses in bottled water. It is important to ensure the use of microbiologically clean source for bottled water as well as implement effective food and water safety management to minimise potential viral contamination.