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Long-term dynamics of Norovirus transmission in Japan, 2005–2019

Norovirus continues to evolve, adjusting its pathogenesis and transmissibility. In the present study, we systematically collected datasets on Norovirus outbreaks in Japan from 2005 to 2019 and analyzed time-dependent changes in the asymptomatic ratio, the probability of virus detection, and the prob...

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Autores principales: Misumi, Megumi, Nishiura, Hiroshi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8280881/
https://www.ncbi.nlm.nih.gov/pubmed/34306831
http://dx.doi.org/10.7717/peerj.11769
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author Misumi, Megumi
Nishiura, Hiroshi
author_facet Misumi, Megumi
Nishiura, Hiroshi
author_sort Misumi, Megumi
collection PubMed
description Norovirus continues to evolve, adjusting its pathogenesis and transmissibility. In the present study, we systematically collected datasets on Norovirus outbreaks in Japan from 2005 to 2019 and analyzed time-dependent changes in the asymptomatic ratio, the probability of virus detection, and the probability of infection given exposure. Reports of 1,728 outbreaks were published, and feces from all involved individuals, including those with asymptomatic infection, were tested for virus in 434 outbreaks. We found that the outbreak size did not markedly change over this period, but the variance in outbreak size increased during the winter (November–April). Assuming that natural history parameters did not vary over time, the asymptomatic ratio, the probability of virus detection, and the probability of infection given exposure were estimated to be 18.6%, 63.3% and 84.5%, respectively. However, a model with time-varying natural history parameters yielded better goodness-of-fit and suggested that the asymptomatic ratio varied by year. The asymptomatic ratio was as high as 25.8% for outbreaks caused by genotype GII.4 noroviruses. We conclude that Norovirus transmissibility has not changed markedly since 2005, and that yearly variation in the asymptomatic ratio could potentially be explained by the circulating dominant genotype.
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spelling pubmed-82808812021-07-23 Long-term dynamics of Norovirus transmission in Japan, 2005–2019 Misumi, Megumi Nishiura, Hiroshi PeerJ Virology Norovirus continues to evolve, adjusting its pathogenesis and transmissibility. In the present study, we systematically collected datasets on Norovirus outbreaks in Japan from 2005 to 2019 and analyzed time-dependent changes in the asymptomatic ratio, the probability of virus detection, and the probability of infection given exposure. Reports of 1,728 outbreaks were published, and feces from all involved individuals, including those with asymptomatic infection, were tested for virus in 434 outbreaks. We found that the outbreak size did not markedly change over this period, but the variance in outbreak size increased during the winter (November–April). Assuming that natural history parameters did not vary over time, the asymptomatic ratio, the probability of virus detection, and the probability of infection given exposure were estimated to be 18.6%, 63.3% and 84.5%, respectively. However, a model with time-varying natural history parameters yielded better goodness-of-fit and suggested that the asymptomatic ratio varied by year. The asymptomatic ratio was as high as 25.8% for outbreaks caused by genotype GII.4 noroviruses. We conclude that Norovirus transmissibility has not changed markedly since 2005, and that yearly variation in the asymptomatic ratio could potentially be explained by the circulating dominant genotype. PeerJ Inc. 2021-07-12 /pmc/articles/PMC8280881/ /pubmed/34306831 http://dx.doi.org/10.7717/peerj.11769 Text en © 2021 Misumi and Nishiura https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Virology
Misumi, Megumi
Nishiura, Hiroshi
Long-term dynamics of Norovirus transmission in Japan, 2005–2019
title Long-term dynamics of Norovirus transmission in Japan, 2005–2019
title_full Long-term dynamics of Norovirus transmission in Japan, 2005–2019
title_fullStr Long-term dynamics of Norovirus transmission in Japan, 2005–2019
title_full_unstemmed Long-term dynamics of Norovirus transmission in Japan, 2005–2019
title_short Long-term dynamics of Norovirus transmission in Japan, 2005–2019
title_sort long-term dynamics of norovirus transmission in japan, 2005–2019
topic Virology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8280881/
https://www.ncbi.nlm.nih.gov/pubmed/34306831
http://dx.doi.org/10.7717/peerj.11769
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