Early Detection of Epidemic GII-4 Norovirus Strains in UK and Malawi: Role of Surveillance of Sporadic Acute Gastroenteritis in Anticipating Global Epidemics.
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. The global molecular epidemiology of emerging GII-4 strains is largely based on data from outbreak surveillance programmes, but the epidemiology of GII-4 strains among sporadic or community cases is far less well studied. To understand the distribution of GII-4 norovirus strains associated with gastroenteritis in the wider population, we characterised the GII-4 norovirus strains detected during studies of sporadic cases of infectious gastroenteritis collected in the UK and Malawi between 1993 and 2009. Our data shows that GII-4 norovirus strains that have emerged as strains of global epidemic importance have circulated in the community up to 18 years before their recognition as pandemic strains associated with increases in outbreaks. These data may suggest that more comprehensive surveillance programmes that incorporate strains associated with sporadic cases may provide a way for early detection of emerging strains with pandemic potential. This may be of particular relevance as vaccines become available.
Virus Reference Department, Public Health England, London, United Kingdom.|NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Liverpool, United Kingdom.
David J
DJ
Allen
Department of Clinical Infection, Microbiology & Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.|St Helens and Knowsley Teaching Hospitals NHS Trust, Liverpool, United Kingdom.
Eamonn
E
Trainor
Virus Reference Department, Public Health England, London, United Kingdom.|Pathogen Molecular Biology Unit, London School of Hygiene & Tropical Medicine, London, United Kingdom.
Anna
A
Callaghan
Department of Epidemiology & Public Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.|NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Liverpool, United Kingdom.
Sarah J
SJ
O'Brien
Department of Clinical Infection, Microbiology & Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Nigel A
NA
Cunliffe
Department of Clinical Infection, Microbiology & Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.|NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Liverpool, United Kingdom.
Miren
M
Iturriza-Gómara
D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D036022:Capsid Proteins / Q000235:genetics; D002675:Child, Preschool; D058872:Epidemics; D062665:Epidemiological Monitoring; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D008295:Malawi / Q000453:epidemiology; D017720:Molecular Epidemiology; D029322:Norovirus / Q000145:classification / Q000235:genetics; D010802:Phylogeny; D012189:Retrospective Studies; D016415:Sequence Alignment; D006113:United Kingdom / Q000453:epidemiology
D036022:Capsid Proteins