Noroviruses (NoVs) are the major causative agents of acute gastroenteritis (AGE) in outbreaks and in sporadic AGE in young children. Since the mid-1990s, NoV genotype GII.4 has been predominant worldwide. New GII.4 variants appear every two to three years, and antigenic variation is focused on the highly variable protruding domain (P2) of the NoV capsid protein which contains the receptor-binding regions. We studied NoV GII.4 variants in cases of endemic AGE in Finnish children from 1998 to 2013. Fecal specimens were collected from cases of AGE followed prospectively in rotavirus vaccine trials from 1998 to 2007, and from children seen at Tampere University Hospital because of AGE from 2006 to 2013. Partial capsid sequences were identified with RT-PCR and sequenced allowing P2 domain alignment and phylogenetic comparison of different GII.4 strains, with virus-like particles (VLPs) developed as candidate vaccines. Of 1495 NoV positive specimens 829 (55%) were of the GII.4 genotype, and altogether twelve GII.4 variants were identified. Identical GII.4 variants were detected in outbreaks of NoVs worldwide. A phylogenetic tree of the amino acid changes in the P2 region showed nine variants that arose over time. Our data indicates that GII.4 continues to be the predominant NoV genotype circulating in the Finnish community, and the changes in the P2 domain over time result in the development of new variants that cause AGE in children. Future NoV vaccines should either induce type specific immunity for each variant or, alternatively, induce broadly reactive protective immunity covering multiple variants.
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http://dx.doi.org/10.1016/j.meegid.2014.05.003 | DOI Listing |
BMC Infect Dis
April 2018
Virology Section, Evandro Chagas Institute, Brazilian Ministry of Health, Rodovia BR-316, Km 7 s/n, Levilândia, Ananindeua, Pará, 67030-000, Brazil.
Background: Globally, Norovirus (NoV) is considered the most common cause of diarrheal episodes across all age groups. Despite its wide genetic diversity, the GII.4 strain is the most predominant and has been associated with epidemics worldwide.
View Article and Find Full Text PDFPLoS One
February 2017
Department of Clinical Infection, Microbiology & Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Noroviruses are endemic in the human population, and are recognised as a leading cause of acute gastroenteritis worldwide. Although they are a highly diverse group of viruses, genogroup-II genotype-4 (GII-4) noroviruses are the most frequently identified strains worldwide. The predominance of GII-4 norovirus strains is driven by the periodic emergence of antigenic variants capable of evading herd protection.
View Article and Find Full Text PDFJ Clin Virol
November 2014
Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address:
Background: The global emergence of norovirus (NoV) GII.4 variants has raised public concerns in the world including South Korea since 1996.
Objective: We analyzed seasonality and genotypic pattern for sporadic cases by norovirus GII-4 variants.
J Infect Dis
December 2014
Vaccine Research Center, University of Tampere Medical School.
PLoS One
October 2014
Virus Reference Department, Microbiology Services, Public Health England, London, United Kingdom.
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