Modelling norovirus dynamics within oysters emphasises potential food safety issues associated with current testing & depuration protocols.

Autor: McMenemy P; University of Strathclyde, 16 Richmond Street, Glasgow, G1 1XQ, United Kingdom; University of Stirling, Airthrey Road, Stirling, FK9 4LA, United Kingdom. Electronic address: paul.mcmenemy@strath.ac.uk., Kleczkowski A; University of Strathclyde, 16 Richmond Street, Glasgow, G1 1XQ, United Kingdom; University of Stirling, Airthrey Road, Stirling, FK9 4LA, United Kingdom. Electronic address: a.kleczkowski@strath.ac.uk., Taylor NGH; Cefas, The Nothe, Barrack Road, Weymouth, DT4 8UB, United Kingdom; Office for National Statistics, 2 Marsham Street, London, SW1P 4DF, United Kingdom.
Jazyk: angličtina
Zdroj: Food microbiology [Food Microbiol] 2023 Dec; Vol. 116, pp. 104363. Date of Electronic Publication: 2023 Aug 18.
DOI: 10.1016/j.fm.2023.104363
Abstrakt: Norovirus is a significant global cause of viral gastroenteritis, with raw oyster consumption often linked to such outbreaks due to their filter-feeding in harvest waters. National water quality and depuration/relaying times are often classified using Escherichia coli, a poor proxy for norovirus levels in shellfish. The current norovirus assay is limited to only the digestive tracts of oysters, meaning the total norovirus load of an oyster may differ from reported results. These limitations motivated this work, building upon previous modelling by the authors, and considers the sequestration of norovirus into observed and cryptic (unobservable) compartments within each oyster. Results show that total norovirus levels in shellfish batches exhibit distinct peaks during the early depuration stages, with each peak's magnitude dependent on the proportion of cryptic norovirus. These results are supported by depuration trial data and other studies, where viral levels often exhibit multiphase decays. This work's significant result is that any future norovirus legislation needs to consider not only the harvest site's water classification but also the total viral load present in oysters entering the market. We show that 62 h of depuration should be undertaken before any norovirus testing is conducted on oyster samples, being the time required for cryptic viral loads to have transited into the digestive tracts where they can be detected by current assay, or have exited the oyster.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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