title: Methods for the detection and characterisation of noroviruses associated with outbreaks of gastroenteritis: outbreaks occurring in the north-west of England during two norovirus seasons.
abstract: This article describes the methods used to investigate 407 outbreaks of acute non-bacterial gastroenteritis occurring in the North-West of England between January 2000 and July 2001 and suspected to be caused by noroviruses (NV) [Mayo (2002) Arch Virol 147:1655-1663]. These included 319 outbreaks in hospitals and nursing homes and 88 other settings. Eight hundred and seventy-one faecal samples from 407 outbreaks were tested using electron microscopy (EM), an enzyme-linked immunosorbent assay (ELISA) specific for Grimsby virus (GRV) capsid antigen and/or by reverse transcriptase-polymerase chain reaction (RT-PCR) for NV, allowing the utility of each assay for routine diagnosis to be assessed. Preliminary genomic characterisation of detected strains was performed using the heteroduplex mobility assay (HMA) and DNA sequencing. The results demonstrate the continuing predominance of GII-4 GRV strain of NV as a cause of outbreaks, particularly in hospital and nursing home settings. Overall, NV were detected in 223/407 (55%) of outbreaks tested. However, a wide range of apparently diverse strains was identified, including several not previously reported. Genomic characterisation revealed clusters of linked outbreaks not recognised previously.
authors.affiliation: Enteric, Respiratory and Neurological Virus Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, Colindale, London, United Kingdom. christopher.gallimore@hpa.org.uk
authors.forename: Chris I
authors.initials: CI
authors.lastname: Gallimore
authors.forename: Jonathan
authors.initials: J
authors.lastname: Green
authors.forename: Alison F
authors.initials: AF
authors.lastname: Richards
authors.forename: Hillary
authors.initials: H
authors.lastname: Cotterill
authors.forename: Alan
authors.initials: A
authors.lastname: Curry
authors.forename: David W G
authors.initials: DW
authors.lastname: Brown
authors.forename: Jim J
authors.initials: JJ
authors.lastname: Gray
mesh_terms: D000956:Antigens, Viral / Q000032:analysis; D017250:Caliciviridae Infections / Q000453:epidemiology / Q000821:virology*; D016000:Cluster Analysis; D004196:Disease Outbreaks; D004739:England / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology / Q000821:virology*; D005838:Genotype; D020180:Heteroduplex Analysis; D006761:Hospitals; D006801:Humans; D008854:Microscopy, Electron; D017720:Molecular Epidemiology; D029322:Norovirus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000648:ultrastructure; D009735:Nursing Homes; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D000956:Antigens, Viral; D012367:RNA, Viral