Norovirus: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
 
(36 intermediate revisions by 6 users not shown)
Line 1: Line 1:
__NOTOC__
__NOTOC__
{{Taxobox
{{Norovirus infection}}
| name = ''Norovirus''
{{About0|Norovirus infection}}
| image = Norwalk.jpg
| image_width = 250px
| image_caption = Transmission electron micrograph of noroviruses. The bar = 50 nm
| virus_group = IV
| familia = ''[[Caliciviridae]]''
| genus = ''Norovirus''
}}
{{CMG}}
{{CMG}}
{{SI}}


==Overview==
==Overview==
'''Norovirus''' (was "Norwalk-like viruses")<ref name=species> [http://www.ncbi.nlm.nih.gov/ICTVdb/Ictv/fs_calic.htm#Genus3 ICTVdB] Family 00.012. Caliciviridae</ref>, an [[RNA virus]] of the [[Caliciviridae]] [[taxonomic rank|taxonomic]] [[family (biology)|family]], causes approximately 90% of [[epidemic]] non-bacterial outbreaks of [[gastroenteritis]] around the world,<ref name="pmid12692541">{{cite journal
[[Norovirus]] is the cause of norovirus infection. Noroviruses ([[genus]] Norovirus) are a group of related, single-stranded [[RNA]], nonenveloped viruses that cause acute gastroenteritis in humans. Noroviruses belong to the family Caliciviridae.
|author=Lindesmith L, Moe C, Marionneau S, ''et al''
==Causes==
|title=Human susceptibility and resistance to Norwalk virus infection
===Common Causes===
|journal=Nat. Med.
Norovirus is transmitted through person-to-person contact, food and water. [[Genotype]] GII.4 is mostly contact transmitted. Non-GII.4 genotypes such as GI.3, GI.6, GI.7, GII.3, GII.6 and GII.12 are mostly [[Food-borne illness|food-borne]]. Genogroup GI strains are more often transmitted through water. This is due to their higher stability in water compared to other [[strains]] of the virus.<ref name="pmid27211790">{{cite journal| author=de Graaf M, van Beek J, Koopmans MP| title=Human norovirus transmission and evolution in a changing world. | journal=Nat Rev Microbiol | year= 2016 | volume= 14 | issue= 7 | pages= 421-33 | pmid=27211790 | doi=10.1038/nrmicro.2016.48 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27211790  }} </ref><ref name="pmid19494060">{{cite journal| author=Lysén M, Thorhagen M, Brytting M, Hjertqvist M, Andersson Y, Hedlund KO| title=Genetic diversity among food-borne and waterborne norovirus strains causing outbreaks in Sweden. | journal=J Clin Microbiol | year= 2009 | volume= 47 | issue= 8 | pages= 2411-8 | pmid=19494060 | doi=10.1128/JCM.02168-08 | pmc=2725682 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19494060  }} </ref>  
|volume=9
|issue=5
|pages=548–53
|year=2003
|pmid=12692541
|doi=10.1038/nm860
}}</ref><ref name="cdcfactsheet">{{cite web |url=http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus-factsheet.htm |title=Norovirus: Technical Fact Sheet |publisher=National Center for Infectious Diseases, CDC}}</ref> and is responsible for 50% of all [[foodborne]] [[outbreak]]s  of gastroenteritis  in the US.<ref name="pmid15705329">{{cite journal
|author=Widdowson MA, Sulka A, Bulens SN, ''et al''
|title=Norovirus and foodborne disease, United States, 1991-2000
|journal=Emerging Infect. Dis.
|volume=11
|issue=1
|pages=95–102
|year=2005
|pmid=15705329
|doi=
|url=http://www.cdc.gov/ncidod/EID/vol11no01/04-0426.htm
}}</ref> Norovirus affects people of all ages. The viruses are transmitted by [[human feces|faecally]] contaminated food or water and by person-to-person contact.<ref name="pmid16968608">{{cite journal
|author=Goodgame R
|title=Norovirus gastroenteritis
|journal=Curr Gastroenterol Rep
|volume=8
|issue=5
|pages=401–8
|year=2006
|pmid=16968608


|doi=10.1007/s11894-006-0026-4
Norovirus is among top ranks of [[Food-borne illness|food-borne]] viruses, globally<ref name="pmid26633896">{{cite journal| author=Havelaar AH, Kirk MD, Torgerson PR, Gibb HJ, Hald T, Lake RJ | display-authors=etal| title=World Health Organization Global Estimates and Regional Comparisons of the Burden of Foodborne Disease in 2010. | journal=PLoS Med | year= 2015 | volume= 12 | issue= 12 | pages= e1001923 | pmid=26633896 | doi=10.1371/journal.pmed.1001923 | pmc=4668832 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26633896  }} </ref>. Transmission could occur in different stages of pre- and post-production of the food products. For instance, [[shellfish]] can be contaminated with fecal discharge in the water<ref name="pmid22440973">{{cite journal| author=Le Guyader FS, Atmar RL, Le Pendu J| title=Transmission of viruses through shellfish: when specific ligands come into play. | journal=Curr Opin Virol | year= 2012 | volume= 2 | issue= 1 | pages= 103-10 | pmid=22440973 | doi=10.1016/j.coviro.2011.10.029 | pmc=3839110 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22440973  }} </ref>, fresh and frozen berries could be contaminated through water contaminated by [[sewage]] or contact during harvesting. Viral [[outbreaks]] through food-borne [[transmission]] can lead to a mixture of the viral strain and increased risk of [[genetic recombination]]. Studies show that about 7% of the foodborne outbreaks have a common source<ref name="pmid21392431">{{cite journal| author=Verhoef L, Kouyos RD, Vennema H, Kroneman A, Siebenga J, van Pelt W | display-authors=etal| title=An integrated approach to identifying international foodborne norovirus outbreaks. | journal=Emerg Infect Dis | year= 2011 | volume= 17 | issue= 3 | pages= 412-8 | pmid=21392431 | doi=10.3201/eid1703.100979 | pmc=3166008 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21392431  }} </ref>.
}}</ref>  


After [[infection]], [[immunity (medical)|immunity]] to norovirus is not complete nor long-lasting.<ref name="pmid15709009">{{cite journal
===Less Common Causes===
|author=Lindesmith L, Moe C, Lependu J, Frelinger JA, Treanor J, Baric RS
Norovirus also has a [[nosocomial]] transition, causing a major burden for health care services<ref name="pmid24981041">{{cite journal| author=Ahmed SM, Hall AJ, Robinson AE, Verhoef L, Premkumar P, Parashar UD | display-authors=etal| title=Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2014 | volume= 14 | issue= 8 | pages= 725-730 | pmid=24981041 | doi=10.1016/S1473-3099(14)70767-4 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24981041  }} </ref>. [[Immunocompromised]] patients may develop numerous norovirus variations due to the [[chronic]] infection. This intra-host viral variation may lead to the appearance of variants not similar to any of the ones of previous outbreaks, thus can escape the herd immunity.<ref name="pmid24648459">{{cite journal| author=Debbink K, Lindesmith LC, Ferris MT, Swanstrom J, Beltramello M, Corti D | display-authors=etal| title=Within-host evolution results in antigenically distinct GII.4 noroviruses. | journal=J Virol | year= 2014 | volume= 88 | issue= 13 | pages= 7244-55 | pmid=24648459 | doi=10.1128/JVI.00203-14 | pmc=4054459 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24648459  }} </ref><ref name="pmid27211790">{{cite journal| author=de Graaf M, van Beek J, Koopmans MP| title=Human norovirus transmission and evolution in a changing world. | journal=Nat Rev Microbiol | year= 2016 | volume= 14 | issue= 7 | pages= 421-33 | pmid=27211790 | doi=10.1038/nrmicro.2016.48 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27211790  }} </ref>
|title=Cellular and humoral immunity following Snow Mountain virus challenge
|journal=J. Virol.
|volume=79
|issue=5
|pages=2900–9
|year=2005
|pmid=15709009
|doi=10.1128/JVI.79.5.2900-2909.2005
|url=http://jvi.asm.org/cgi/pmidlookup?view=long&pmid=15709009
}}</ref> There is an [[genetic|inherited]] predisposition to infection and people whose [[blood type]] can be detected in their [[saliva]] are more often infected.<ref name="pmid12692541">{{cite journal
|author=Lindesmith L, Moe C, Marionneau S, ''et al''
|title=Human susceptibility and resistance to Norwalk virus infection
|journal=Nat. Med.
|volume=9
|issue=5
|pages=548–53
|year=2003
|pmid=12692541
|doi=10.1038/nm860
}}</ref>


Outbreaks of norovirus [[disease]] often occur in closed or semi-closed communities, such as long-term care facilities, hospitals, prisons, dormitories, and cruise ships where once the virus has been introduced,  the infection spreads very rapidly by either person-to-person transmission or through contaminated food.<ref name="pmid18177970">{{cite journal
To date, animal norovirus strains have not been reported to infect human population, but there has been evidence of intra-species transmission. Human norovirus has been detected in the [[stools]] of pigs, cattle and dogs.<ref name="pmid27211790">{{cite journal| author=de Graaf M, van Beek J, Koopmans MP| title=Human norovirus transmission and evolution in a changing world. | journal=Nat Rev Microbiol | year= 2016 | volume= 14 | issue= 7 | pages= 421-33 | pmid=27211790 | doi=10.1038/nrmicro.2016.48 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27211790  }} </ref>
|author=Noda M, Fukuda S, Nishio O
|title=Statistical analysis of attack rate in norovirus foodborne outbreaks
|journal=Int J Food Microbiol
|volume=
|issue=


|pages=216
==References==
|year=2007
{{Reflist|2}}
|pmid=18177970
|doi=10.1016/j.ijfoodmicro.2007.11.073
|url=http://linkinghub.elsevier.com/retrieve/pii/S0168-1605(07)00662-9
}}</ref> Many norovirus outbreaks have been traced to food that was handled by one infected person.<ref name="pmid14672828">{{cite journal
|author=Koopmans M, Duizer E
|title=Foodborne viruses: an emerging problem
|journal=Int. J. Food Microbiol.
|volume=90
|issue=1
|pages=23–41
|year=2004
|pmid=14672828


|doi=10.1016/S0168-1605(03)00169-7
{{WikiDoc Help Menu}}
|url=http://linkinghub.elsevier.com/retrieve/pii/S0168160503001697
{{WikiDoc Sources}}
}}</ref>


Norovirus is rapidly killed by [[sodium hypochlorite|chlorine-based]] [[disinfectant]]s, but because the [[virion|virus particle]] does not have a [[lipid]] [[viral envelope|envelope]], it is less susceptible to [[alcohol]]s and [[detergent]]s.<ref name="pmid16765204">{{cite journal
[[Category:Disease]]
|author=Jimenez L, Chiang M
|title=Virucidal activity of a quaternary ammonium compound disinfectant against feline calicivirus: a surrogate for norovirus
|journal=Am J Infect Control
|volume=34
|issue=5
|pages=269–73
|year=2006
|pmid=16765204
|doi=10.1016/j.ajic.2005.11.009
|url=http://linkinghub.elsevier.com/retrieve/pii/S0196-6553(06)00078-2
}}</ref>


There are different [[genotype|genogroups]] of norovirus and the majority of noroviruses that infect humans are classified into genogroup G1 and G2.<ref name="pmid10752550">{{cite journal
[[Category:Viral diseases]]
|author=Vinjé J, Green J, Lewis DC, Gallimore CI, Brown DW, Koopmans MP
|title=Genetic polymorphism across regions of the three open reading frames of "Norwalk-like viruses"
|journal=Arch. Virol.
|volume=145
|issue=2
|pages=223–41
|year=2000
|pmid=10752550
|doi=
|url=http://link.springer.de/link/service/journals/00705/bibs/0145002/01450223.htm
}}</ref>
 
==Historical Perspective==
Originally, norovirus was named after [[Norwalk, Ohio]], where an outbreak of acute [[gastroenteritis]] occurred among children at an [[primary education|elementary school]] in November 1968. In 1972, immune electron microscopy on stored [[Human feces|stool]] samples identified a virus, which was given the name Norwalk virus. Numerous outbreaks with similar symptoms have been reported since. The [[cloning]] and [[sequencing]] of the Norwalk virus genome showed that these viruses have a genomic organization consistent with viruses belonging to the family [[Caliciviridae]].<ref name="pmid9015097">{{cite journal
|author=Kapikian AZ
|title=Overview of viral gastroenteritis
|journal=Arch. Virol. Suppl.
|volume=12
|issue=
|pages=7–19
|year=1996
|pmid=9015097
|doi=
|issn=
}}</ref> The name norovirus (''Norovirus'' for the genus) was approved by the [[International Committee on Taxonomy of Viruses]] in 2002. <ref>ICTVdB Management (2006). 00.012.0.03. Norovirus. In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C. (Ed), Columbia University, New York, USA </ref>
 
Common names of the illness caused by noroviruses are winter vomiting disease, viral [[gastroenteritis]] and acute non-bacterial gastroenteritis<ref name="pmid16968608">{{cite journal
|author=Goodgame R
|title=Norovirus gastroenteritis
|journal=Curr Gastroenterol Rep
|volume=8
|issue=5
|pages=401–8
|year=2006
|pmid=16968608
 
|doi=10.1007/s11894-006-0026-4
|issn=
}}</ref>, also colloquially known as "[[stomach flu]]" (a broad name which can also refer to gastric inflammation caused by other viruses and bacteria).
 
Some previously used names which can be used for [[PubMed]] and other internet searches are Norwalk virus, Norwalk-like virus, SRSVs (Small Round Structured Viruses), Sapporo virus and Snow Mountain.<ref name="pmid3036438">{{cite journal
|author=Appleton H
|title=Small round viruses: classification and role in food-borne infections
|journal=Ciba Found. Symp.
|volume=128
|issue=
|pages=108–25
|year=1987
|pmid=3036438
|doi=
}}</ref>
 
==Natural History, Complications and Prognosis==
*Incubation 24-48 hours
*Onset can be gradual or abrupt
*[[Diarrhea]] is moderate volume, noninflammatory, mechanism is unknown (no detectable [[enterotoxin]])
*Lasts 48-72 hours with full and rapid recovery
 
== Signs and symptoms ==
The disease is usually [[self-limiting]], and characterised by [[nausea]], vomiting, [[diarrhea]], and abdominal pain. General lethargy, weakness, muscle aches, headache, and low-grade fever may occur. Symptoms may persist for several days and may become life-threatening in the young, the elderly, and the immune-compromised if [[dehydration]] is ignored or not treated.<ref name="pmid16968608">{{cite journal
|author=Goodgame R
|title=Norovirus gastroenteritis
|journal=Curr Gastroenterol Rep
|volume=8
|issue=5
|pages=401–8
|year=2006
|pmid=16968608
 
|doi=10.1007/s11894-006-0026-4
|issn=
}}</ref>
 
==Diagnosis ==
Specific diagnosis of norovirus is routinely made by [[polymerase chain reaction]] (PCR) [[assay]]s or [[Real-time polymerase chain reaction|real-time PCR]] assays, which give results within a few hours. These assays are very sensitive and can detect concentrations as low as 10 virus particles.<ref name="pmid17175887">{{cite journal
|author=Marshall JA, Bruggink LD
|title=Laboratory diagnosis of norovirus
|journal=Clin. Lab.
|volume=52
|issue=11-12
|pages=571–81
|year=2006
|pmid=17175887
|doi=
|issn=
}}</ref>
 
Tests such as [[EIA]] that use [[antibody|antibodies]] against a mixture of norovirus strains are  available commercially but lack [[Specificity (tests)|specificity]] and [[Sensitivity (tests)|sensitivity]].<ref name="pmid17391396">{{cite journal
|author=Wilhelmi de Cal I, Revilla A, del Alamo JM, Román E, Moreno S, Sánchez-Fauquier A
|title=Evaluation of two commercial enzyme immunoassays for the detection of norovirus in faecal samples from hospitalised children with sporadic acute gastroenteritis
|journal=Clin. Microbiol. Infect.
|volume=13
|issue=3
|pages=341–3
|year=2007
|pmid=17391396
|doi=10.1111/j.1469-0691.2006.01594.x
|url=http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=1198-743X&date=2007&volume=13&issue=3&spage=341
|issn=
}}</ref>
 
===Physical Examination===
Noroviruses present as:
 
*Mild febrile illnesss with watery [[diarrhea]] or
*Severe febrile illness with [[vomiting]], [[headache]], etc.
*First symptoms are usually [[cramps]] and/or [[nausea]]
**Most have both vomiting and diarrhea but can have either
*Headache
*[[Myalgia]]s
*[[Malaise]] in about 50%
 
====Vital Signs====
*Temperature of 101-102
 
== Prevention and infection control ==
[[Hand washing]] remains an effective method to reduce the spread of norovirus [[pathogen]]s. Norovirus can be [[aerosolized]] when those stricken with the illness vomit. Surface sanitizing is recommended in areas where the Norovirus may be present on surfaces.
 
In health care environments, the prevention of [[nosocomial infection]]s involves routine and [[terminal cleaning]]. [[Nonflammable alcohol vapor in CO2]] systems are used in health care environments where medical electronics would be adversely affected by aerosolized chlorine or other caustic compounds.<ref name="pmid10833336">{{cite journal
|author=Chadwick PR, Beards G, Brown D, Caul EO, Cheesbrough J, Clarke I, Curry A, O'Brien S, Quigley K, Sellwood J, Westmoreland D
|title=Management of hospital outbreaks of gastro-enteritis due to small roundstructured viruses
|journal=J. Hosp. Infect.
|volume=45
|issue=1
|pages=1–10
|year=2000
|pmid=10833336
|doi=10.1053/jhin.2000.0662
|url=http://linkinghub.elsevier.com/retrieve/pii/jhin.2000.0662
|issn=
}}</ref>
 
Ligocyte is working on a vaccine and has already started phase 1 trials.  http://www.ligocyte.com/pdf/norovirus.pdf
 
== Associated foods ==
Noroviruses are transmitted directly via person to person or indirectly via contaminated water and foods. A [[Centers for Disease Control and Prevention|CDC]] study of eleven outbreaks in [[New York|New York State]] lists  the suspected [[Transmission (medicine)|mode of transmission]] as person-to-person in seven outbreaks, foodborne in two, waterborne in one, and one unknown. The source of waterborne outbreaks may include water from municipal supplies, wells, recreational lakes, swimming pools and ice machines. <ref name="pmid8395330">{{cite journal
|author=Hedberg CW, Osterholm MT
|title=Outbreaks of food-borne and waterborne viral gastroenteritis
|journal=Clin. Microbiol. Rev.
|volume=6
|issue=3
|pages=199–210
|year=1993
|pmid=8395330
|doi=
|url=http://cmr.asm.org/cgi/pmidlookup?view=long&pmid=8395330
|issn=
}}</ref>
 
[[Shellfish]] and [[salad]] ingredients are the foods most often implicated in Norwalk outbreaks. Ingestion of raw or insufficiently steamed [[clam]]s and [[oyster]]s poses a high risk for infection with the Norwalk virus. Foods other than shellfish are contaminated by ill food handlers.<ref name="pmid11479930">{{cite journal
|author=Parashar UD, Monroe SS
|title="Norwalk-like viruses" as a cause of foodborne disease outbreaks
|journal=Rev. Med. Virol.
|volume=11
|issue=4
|pages=243–52
|year=2001
|pmid=11479930
|doi=10.1002/rmv.321
|issn=
}}</ref>
 
== Relative frequency of disease ==
Only the [[common cold]] is reported more frequently than viral gastroenteritis as a cause of illness in the U.S. Although viral gastroenteritis is caused by a number of viruses, it is estimated that noroviruses are responsible for about 1/3 of the cases over the 6-to-24-month age group.  In developing countries the percentage of individuals who have developed immunity at an early age is very high. In the U.S. the percentage increases gradually with age, reaching 50% in the population over 18 years of age. Immunity, however, is not permanent and reinfection can occur. Recent studies demonstrate that [[blood type]]s B and AB confer partial protection against symptomatic infection.<ref>{{cite news |url=http://www.journals.uchicago.edu/cgi-bin/resolve?doi=10.1086/339883&erFrom=-6346711085704863031Guest/
|accessdate=2007-02-05 |title=Norwalk Virus Infection and Disease Is Associated with ABO Histo-Blood Group Type |publisher=[[The Journal of Infectious Diseases]]|date=2002}}</ref><ref>{{cite news|url=http://jvi.asm.org/cgi/content/full/76/23/12335/ |accessdate=2007-02-05 |title=Binding of Norwalk Virus-Like Particles to ABH Histo-Blood Group Antigens Is Blocked by Antisera from Infected Human Volunteers or Experimentally Vaccinated Mice |publisher=[[Journal of Virology]] |date=2002}}</ref>
 
== Course of disease and complications ==
Norovirus causes acute [[gastroenteritis]] that develops between 24 and 48 hours after exposure with a median of 33-36 hours, and lasts for 24-60 hours.<ref name="cdcfactsheet"/> Severe illness  is rare: although people are frequently treated in emergency rooms/A&E, they are rarely admitted to the hospital. The number of deaths from norovirus in the US is estimated to be around 300 each year, with most of these occurring in the very young, elderly and persons with weakened immune systems.
 
== Detection of norovirus in foods==
Routine protocols to detect norovirus (norovirus RNA) in clams and oysters by RT-PCR (reverse transcription polymerase chain reaction) are being employed by governmental laboratories such as the FDA in the USA. However, routine methods to detect the virus on other food items are not readily available due to the variable nature of different food items affecting concentration and extraction of the virus and presence of factors that make PCR (Polymerase chain reaction) analysis techniques ineffective.<ref name="pmid10804149">{{cite journal
|author=Shieh Y, Monroe SS, Fankhauser RL, Langlois GW, Burkhardt W, Baric RS
|title=Detection of norwalk-like virus in shellfish implicated in illness
|journal=J. Infect. Dis.
|volume=181 Suppl 2
|issue=
|pages=S360–6
|year=2000
|pmid=10804149
|doi=
|url=http://www.journals.uchicago.edu/cgi-bin/resolve?JID990682
|issn=
}}</ref>
 
==Outbreaks==
<!-- Due to the frequency of outbreaks, it has been decided to include only once in 20 year events and the largest cruise ship outbreak. Before adding any outbreak, please discuss it's notability on [[Talk:Norovirus#Proposal - Notable outbreaks]], thanks -->
 
*In [[November 2006]], 679 (17%) out of 3,970 passengers and crew members aboard the trans-Atlantic [[Carnival Cruise Lines]]' ''[[Carnival Liberty]]'', one of the world's largest cruise ships, contracted the virus. <ref>
{{cite web
  | title = Investigation Update on the Carnival Liberty
  | work = [[Centers for Disease Control and Prevention]] (CDC)
  | publisher = [[United States Department of Health and Human Services]]
  | date = [[25 November]] [[2006]]
  | url = http://www.cdc.gov/nceh/vsp/surv/outbreak/2006/nov13carnivalliberty.htm
}}
</ref>
==Microbiology==
===Classification===
[[Image:Norovirus 4.jpg|right|thumb|250px|Transmission electron micrograph of Norovirus particles in faeces]]
 
Noroviruses (NoV) are a genetically diverse group of single stranded RNA, nonenveloped viruses belonging to the Caliciviridae family.<ref name=health> [http://www.health.gov.au/internet/main/publishing.nsf/Content/cda-phlncd-norwalk.htm  Department of Health and Ageing] Norovirus laboratory case definition</ref> According to the International Committee on Taxonomy of Virus, the [[genus]] Norovirus has one species which is called "Norwalk virus" and assigned the abbreviation "NV". Serotypes, strains and isolates include:<ref name=species/>
*Desert Shield virus [U04469] (Hu/NLV/DSV395/1990/SR)
*Lordsdale virus [X86557] (Hu/NLV/LD/1993/UK)
*Mexico virus [U22498] (Hu/NLV/MX/1989/MX)
*Norwalk virus [M87661] (Hu/NLV/NV/1968/US)
*Hawaii virus [U07611] (Hu/NLV/HV/1971/US)
*Snow Mountain virus [L23831] (Hu/NLV/SMV/1976/US)
*Southampton virus [L07418] (Hu/NLV/SHV/1991/UK)
 
"Noroviruses are a major cause of acute gastroenteritis worldwide, often causing explosive outbreaks in institutions. They are highly contagious, with an inoculum of as few as ten particles being able to cause infection. Transmission occurs through ingesting contaminated food and water and by person-to-person spread. Transmission is predominantly faecal-oral but may be airborne due to aerosolisation of vomitus [...] Noroviruses commonly isolated in cases of acute gastroenteritis belong to two genogroups: genogroup I (GI) includes Norwalk virus, Desert Shield virus and Southampton virus and II (GII) which includes Bristol virus, Lordsdale virus, Toronto virus, Mexico virus, Hawaii virus and Snow Mountain virus."<ref name=health/>
 
Noroviruses can genetically be classified into 5 different genogroups (GI, GII, GIII, GIV, and GV) which can be further divided into different genetic clusters or [[genotype]]s. For example genogroup II, the most prevalent human genogroup, presently contains 19 genotypes. Genogroups I, II and IV infect humans, whereas genogroup III infects [[Bovinae|bovine species]] and genogroup V has recently been isolated in mice.<ref name="pmid17953996">{{cite journal
|author=Ramirez S, Giammanco GM, De Grazia S, Colomba C, Martella V, Arista S
|title=Genotyping of GII.4 and GIIb norovirus RT-PCR amplicons by RFLP analysis
|journal=J. Virol. Methods
|volume=147
|issue=2
|pages=250–6
|year=2008
|pmid=17953996
|doi=10.1016/j.jviromet.2007.09.005
|url=http://linkinghub.elsevier.com/retrieve/pii/S0166-0934(07)00362-X
|issn=
}}</ref>
 
Noroviruses from Genogroup II, genotype 4 (abbreviated as GII.4) account for the majority of adult outbreaks of [[gastroenteritis]] and often sweep across the globe. Recent examples include US95/96-US strain, associated with global outbreaks in the mid- to late-90s, [[Farmington Hills]] virus associated with outbreaks in [[Europe]] and the [[United States]] in 2002 and in 2004 Hunter virus was associated with outbreaks in [[Europe]], [[Japan]] and [[Australasia]]. In 2006 there was another large increase in NoV infection around the globe.<ref name="pmid18177226">{{cite journal
|author=Tu ET, Bull RA, Greening GE, Hewitt J, Lyon MJ, Marshall JA, McIver CJ, Rawlinson WD, White PA
|title=Epidemics of gastroenteritis during 2006 were associated with the spread of norovirus GII.4 variants 2006a and 2006b
|journal=Clin. Infect. Dis.
|volume=46
|issue=3
|pages=413–20
|year=2008
|pmid=18177226
|doi=10.1086/525259
|url=http://bjr.birjournals.org/cgi/pmidlookup?view=long&pmid=18177226
|issn=
}}</ref> In December, 2007 there was an outbreak at a country club in northern California where around 80-100 people were infected. Two new GII.4 variants caused around 80% of those Norovirus associated outbreaks and they have been termed 2006a and 2006b. Recent reports have shown a link between blood group and susceptibility to infection by norovirus.<ref name="pmid12825167">{{cite journal
|author=Huang P, Farkas T, Marionneau S, Zhong W, Ruvoën-Clouet N, Morrow AL, Altaye M, Pickering LK, Newburg DS, LePendu J, Jiang X
|title=Noroviruses bind to human ABO, Lewis, and secretor histo-blood group antigens: identification of 4 distinct strain-specific patterns
|journal=J. Infect. Dis.
|volume=188
|issue=1
|pages=19–31
|year=2003
|pmid=12825167
 
|doi=10.1086/375742
|url=http://www.journals.uchicago.edu/cgi-bin/resolve?JID30248
}}</ref><ref name="pmid15890909">{{cite journal
|author=Huang P, Farkas T, Zhong W, Tan M, Thornton S, Morrow AL, Jiang X
|title=Norovirus and histo-blood group antigens: demonstration of a wide spectrum of strain specificities and classification of two major binding groups among multiple binding patterns
|journal=J. Virol.
|volume=79
|issue=11
|pages=6714–22
|year=2005
|pmid=15890909
|doi=10.1128/JVI.79.11.6714-6722.2005
|url=http://jvi.asm.org/cgi/pmidlookup?view=long&pmid=15890909
}}</ref><ref name="pmid15688291">{{cite journal
|author=Rockx BH, Vennema H, Hoebe CJ, Duizer E, Koopmans MP
|title=Association of histo-blood group antigens and susceptibility to norovirus infections
|journal=J. Infect. Dis.
|volume=191
|issue=5
|pages=749–54
|year=2005
|pmid=15688291
|doi=10.1086/427779
|url=http://www.journals.uchicago.edu/cgi-bin/resolve?JID33169
}}</ref>
 
===Virus structure===
Noroviruses contain a [[Sense (molecular biology)|positive-sense]] [[RNA]] [[genome]] of approximately 7.5 [[Base pair#Length measurements|kbp]], encoding a major structural [[protein]] (VP1) of about 58~60 [[kDa]] and a minor [[capsid]] protein (VP2).<ref name="pmid10804143">{{cite journal
|author=Clarke IN, Lambden PR
|title=Organization and expression of calicivirus genes
|journal=J. Infect. Dis.
|volume=181 Suppl 2
|issue=
|pages=S309–16
|year=2000
|pmid=10804143
|doi=
|url=http://www.journals.uchicago.edu/cgi-bin/resolve?JID990679
|issn=
}}</ref> The virus particles demonstrate an amorphous surface structure when visualized using [[electron microscopy]] and are between 27-38 [[Meter#SI prefixed forms of metre|nm]] in size.<ref name="pmid11444031">{{cite journal
|author=Prasad BV, Crawford S, Lawton JA, Pesavento J, Hardy M, Estes MK
|title=Structural studies on gastroenteritis viruses
|journal=Novartis Found. Symp.
|volume=238
|issue=
|pages=26–37; discussion 37–46
|year=2001
|pmid=11444031
|doi=
|issn=
}}</ref>
 
== References ==
{{reflist|2}}
 
== External links ==
* [http://news.bbc.co.uk/1/hi/health/7169347.stm BBC News Jan 2008 - Stomach bug sweeping the country]
* [http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus-qa.htm CDC Viral Gastroenteritis FAQs]: Center for Disease Control and Prevention of Food Illness Fact Sheet
* [http://www.cdc.gov/ncidod/dhqp/id_norovirusFS.html "Norovirus in Healthcare Facilities Fact Sheet"], CDC, released [[December 21]], 2006
* [http://www.wandsworth-pct.nhs.uk/pdf/factsheets/WinterVomitingSRSV_NLV.pdf Winter Vomiting Disease] &ndash; UK government factsheet
{{viruses}}
<br>
 
[[Category:Viruses]]
 
[[da:Roskildesyge]]
[[de:Norovirus]]
[[fr:Virus de Norwalk]]
[[ko:노로바이러스]]
[[nl:Norovirus]]
[[ja:ノロウイルス]]
[[no:Norovirus]]
[[fi:Norovirukset]]
[[sv:Vinterkräksjuka]]
[[tr:Norwalk virüsü]]
[[zh:诺罗病毒]]
 
{{WH}}
{{WS}}
{{jb1}}

Latest revision as of 17:29, 8 March 2021

Norovirus infection Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Norovirus infection from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

Diagnostic study of choice

History and Symptoms

Physical Examination

Laboratory Findings

Treatment

Medical Therapy

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Norovirus On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Norovirus

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Norovirus

CDC on Norovirus

Norovirus in the news

Blogs on Norovirus

Directions to Hospitals Treating Norovirus infection

Risk calculators and risk factors for Norovirus

This page is about microbiologic aspects of the organism(s).  For clinical aspects of the disease, see Norovirus infection.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Norovirus is the cause of norovirus infection. Noroviruses (genus Norovirus) are a group of related, single-stranded RNA, nonenveloped viruses that cause acute gastroenteritis in humans. Noroviruses belong to the family Caliciviridae.

Causes

Common Causes

Norovirus is transmitted through person-to-person contact, food and water. Genotype GII.4 is mostly contact transmitted. Non-GII.4 genotypes such as GI.3, GI.6, GI.7, GII.3, GII.6 and GII.12 are mostly food-borne. Genogroup GI strains are more often transmitted through water. This is due to their higher stability in water compared to other strains of the virus.[1][2]

Norovirus is among top ranks of food-borne viruses, globally[3]. Transmission could occur in different stages of pre- and post-production of the food products. For instance, shellfish can be contaminated with fecal discharge in the water[4], fresh and frozen berries could be contaminated through water contaminated by sewage or contact during harvesting. Viral outbreaks through food-borne transmission can lead to a mixture of the viral strain and increased risk of genetic recombination. Studies show that about 7% of the foodborne outbreaks have a common source[5].

Less Common Causes

Norovirus also has a nosocomial transition, causing a major burden for health care services[6]. Immunocompromised patients may develop numerous norovirus variations due to the chronic infection. This intra-host viral variation may lead to the appearance of variants not similar to any of the ones of previous outbreaks, thus can escape the herd immunity.[7][1]

To date, animal norovirus strains have not been reported to infect human population, but there has been evidence of intra-species transmission. Human norovirus has been detected in the stools of pigs, cattle and dogs.[1]

References

  1. ↑ 1.0 1.1 1.2 de Graaf M, van Beek J, Koopmans MP (2016). "Human norovirus transmission and evolution in a changing world". Nat Rev Microbiol. 14 (7): 421–33. doi:10.1038/nrmicro.2016.48. PMID 27211790.
  2. ↑ Lysén M, Thorhagen M, Brytting M, Hjertqvist M, Andersson Y, Hedlund KO (2009). "Genetic diversity among food-borne and waterborne norovirus strains causing outbreaks in Sweden". J Clin Microbiol. 47 (8): 2411–8. doi:10.1128/JCM.02168-08. PMC 2725682. PMID 19494060.
  3. ↑ Havelaar AH, Kirk MD, Torgerson PR, Gibb HJ, Hald T, Lake RJ; et al. (2015). "World Health Organization Global Estimates and Regional Comparisons of the Burden of Foodborne Disease in 2010". PLoS Med. 12 (12): e1001923. doi:10.1371/journal.pmed.1001923. PMC 4668832. PMID 26633896.
  4. ↑ Le Guyader FS, Atmar RL, Le Pendu J (2012). "Transmission of viruses through shellfish: when specific ligands come into play". Curr Opin Virol. 2 (1): 103–10. doi:10.1016/j.coviro.2011.10.029. PMC 3839110. PMID 22440973.
  5. ↑ Verhoef L, Kouyos RD, Vennema H, Kroneman A, Siebenga J, van Pelt W; et al. (2011). "An integrated approach to identifying international foodborne norovirus outbreaks". Emerg Infect Dis. 17 (3): 412–8. doi:10.3201/eid1703.100979. PMC 3166008. PMID 21392431.
  6. ↑ Ahmed SM, Hall AJ, Robinson AE, Verhoef L, Premkumar P, Parashar UD; et al. (2014). "Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis". Lancet Infect Dis. 14 (8): 725–730. doi:10.1016/S1473-3099(14)70767-4. PMID 24981041.
  7. ↑ Debbink K, Lindesmith LC, Ferris MT, Swanstrom J, Beltramello M, Corti D; et al. (2014). "Within-host evolution results in antigenically distinct GII.4 noroviruses". J Virol. 88 (13): 7244–55. doi:10.1128/JVI.00203-14. PMC 4054459. PMID 24648459.


Template:WikiDoc Sources

Retrieved from "https://www.wikidoc.org/index.php?title=Norovirus&oldid=1693776"