Human norovirus surrogates persist in nontraditional sources of irrigation water in excess of 100 days.

Human norovirus (HuNoV) has been implicated as the leading cause of foodborne illness worldwide. The ability of HuNoV to persist in water can significantly impact food safety as agriculture and processing water could serve as vehicles of virus transmission. This study focused on the persistence and infectivity of the HuNoV surrogate viruses, Murine norovirus (MNV), and Tulane virus (TV), after prolonged storage in diverse environmental water types currently used for agricultural irrigation. In this study, vegetable processing water (VW), brackish tidal surface water (SW), municipal reclaimed water (RW), and pond water (PW) were inoculated with each virus in a 1:10 v/v ratio containing virus at 3.5-4.5 logPFU/mL and stored at 16°C for 100 days. This time and temperature combination was chosen to mimic growing and harvest conditions in the mid-Atlantic area of the United States. Samples were then assayed for the presence of viral RNA using reverse transcription-quantitative polymerase chain...