High viral shedding in hospitalized patients infected with emerging recombinant norovirus GII.P16-GII.2
Refereed conference paper presented and published in conference proceedings

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AbstractIntroduction: Norovirus is the leading cause of acute gastroenteritis and evolves through mutation and recombination. In 2016, a new recombinant norovirus genotype called GII.P16-GII.2 emerged and spread widely in Asia and Europe. We studied fecal viral shedding of this new norovirus.

Methods: This was a 5-year observational cohort study. Stool samples were collected from in-patients with norovirus gastroenteritis between August 2012 and June 2017. Fecal viral load (VL) of GII.P16-GII.2 (n=136) and pandemic GII.Pe-GII.4 (n=657) in norovirus-positive samples was measured by quantitative real-time RT-PCR assay. Lower cycle threshold (Ct) value represents higher VL. We compared VL among age groups and norovirus genotypes with statistical Mann-Whitney U test.

Results: GII.P16-GII.2 had the highest VL. In young children aged <5 years, the median VL of GII.P16-GII.2 was indistinguishably high to that of GII.Pe-GII.4 (median Ct [IQR]: 15.2 [12.9-18.8] versus 16.7 [14.8-19.0]; p=0.200). The median VL of GII.P16-GII.2 was 28 and 45 folds higher than that of GII.Pe-GII.4 in those aged 5-65 years and >65 years, respectively. Unlike GII.Pe-GII.4, high VL of GII.P16-GII.2 did not reduce with age. Similar trends were confirmed by subgroup analysis according to first season of emergence. RT-PCR amplification efficiency did not differ between genotypes (mean ≥94%). Over 96% of low VL samples were free of primer-probe mismatch, excluding quantification artefacts.

Conclusion: High viral shedding of GII.P16-GII.2 was observed in all age groups, including older children and adults previously less vulnerable to severe gastroenteritis. High viral shedding in children explains the recent upsurge of GII.P16-GII.2 outbreaks in schools.
All Author(s) ListSarah K.C. Cheung, Kirsty Kwok, Lin-Yao Zhang, Kirran N. Mohammad, Grace C.Y. Lui, Nelson Lee, E. Anthony S. Nelson, Raymond W.M. Lai, Ting F. Leung, Paul K.S. Chan, Martin Chi-Wai Chan
Name of Conference21st Annual Meeting of the European Society for Clinical Virology
Start Date of Conference23/09/2018
End Date of Conference26/09/2018
Place of ConferenceAthens
Country/Region of ConferenceGreece
Proceedings Title21st ESCV Abstract Book
Place of PublicationGreece
Pages29 - 29
LanguagesEnglish-United Kingdom

Last updated on 2018-06-12 at 11:06