Viable Norovirus Persistence in Aquatic Microenvironments: Insights and Findings

News 26 11 月, 2024

Introduction

Human norovirus is the leading cause of acute gastroenteritis worldwide. Despite its significant public health impact, human norovirus remains challenging to cultivate in laboratory conditions. Consequently, environmental fate studies of norovirus rely on molecular methods or culturable surrogate viruses. However, these methods often overestimate the presence of infectious viruses as they detect damaged, non-infectious viral particles. A groundbreaking study by Marlee Shaffer and colleagues utilized human intestinal enteroids (HIE) to assess viable norovirus persistence in tap water, surface water, and ultrapure water. This approach provided a comparison between traditional molecular methods and the infectious potential of noroviruses, revealing a gap between the two.

Materials and Methods

Water samples were collected from laboratory systems and surface sources, including ultrapure water, tap water, and surface water. Using HIE cells derived from adult intestinal stem cells (Lgr5+), researchers infected water samples with GII.4 Sydney[P31] norovirus-positive stool filtrates. Samples were observed over a 28-day period, comparing the decay of viable noroviruses with RNA levels measured via RT-qPCR.

Results

As shown in Figure 1, norovirus RNA signals amplified through HIE assays declined steadily over the 28-day period, with viable norovirus dropping below detection limits in tap and deionized water microcosms. In contrast, no significant RNA decay was observed when using RT-qPCR to measure RNA levels throughout the experiment. The estimated decay rates of viable norovirus using HIE assays were 0.11±0.020.11 ± 0.020.11±0.02 day−1^{-1}−1, 0.08±0.020.08 ± 0.020.08±0.02 day−1^{-1}−1, and 0.10±0.010.10 ± 0.010.10±0.01 day−1^{-1}−1 for surface water, tap water, and ultrapure water, respectively. No significant differences were observed in the kkk-values among the different water types.

Reference

Shaffer M, Huynh K, Costantini V, Bibby K, Vinjé J. Viable Norovirus Persistence in Water Microcosms. Environ Sci Technol Lett. 2022;9(10):851-855. doi:10.1021/acs.estlett.2c00553