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Norovirus
Transmission electron micrograph of noroviruses. The bar = 50 nm
Transmission electron micrograph of noroviruses. The bar = 50 nm
Virus classification
Group: Group IV ((+)ssRNA)
Family: Caliciviridae
Genus: Norovirus

Norovirus (was "Norwalk-like viruses")[1], an RNA virus of the Caliciviridae taxonomic family, causes approximately 90% of epidemic non-bacterial outbreaks of gastroenteritis around the world,[2][3] and is responsible for 50% of all foodborne outbreaks of gastroenteritis in the US. Virus classification involves naming and placing Viruses into a taxonomic system An RNA virus is a Virus that has RNA (ribonucleic acid as its Genetic material. The Caliciviridae family are a family of Viruses, members of Class IV of the Baltimore scheme. An RNA virus is a Virus that has RNA (ribonucleic acid as its Genetic material. The Caliciviridae family are a family of Viruses, members of Class IV of the Baltimore scheme. Taxonomic rank ( rank, category, taxonomic category is an abstract term used in the Scientific classification, or Taxonomy, of organisms In Biological classification, family ( Latin In Epidemiology, an epidemic (from Greek epi- upon + demos people is a classification of a disease that appears as new cases in a Gastroenteritis (also known as gastro, gastric flu, and stomach flu, although unrelated to Influenza) is Inflammation of the Foodborne illness (also foodborne disease) is any Illness resulting from the consumption of food Outbreak is a classification used in Epidemiology to describe a small localized group of people or organisms infected with a disease [4] Norovirus affects people of all ages. The viruses are transmitted by faecally contaminated food or water and by person-to-person contact. Human Feces (also faeces &mdash see spelling differences) also known as stools, is the waste product of the human digestive system and varies significantly [5]

After infection, immunity to norovirus is not complete nor long-lasting. An infection is the detrimental Colonization of a host Organism by a foreign Species. Immunity is a material term that describes a state of having sufficient biological defenses to avoid Infection, Disease, or other unwanted biological invasion [6] There is an inherited predisposition to infection and people whose blood type can be detected in their saliva are more often infected. A blood type (also called a blood group) is a classification of Blood based on the presence or absence of inherited Antigenic substances on the For the band see Saliva (band; for the village in Azerbaijan see Səliva. [2]

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. A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly [7] Many norovirus outbreaks have been traced to food that was handled by one infected person. [8]

Norovirus is rapidly killed by chlorine-based disinfectants, but because the virus particle does not have a lipid envelope, it is less susceptible to alcohols and detergents. Sodium hypochlorite is a Chemical compound with the formula NaClO Disinfectants are Antimicrobial agents that are applied to non-living objects to destroy Microorganisms, the process of which is known as disinfection. A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable Lipids are broadly defined as any fat- Soluble ( lipophilic) naturally-occurring Molecule, such as fats oils waxes cholesterol sterols fat-soluble Many Viruses (eg influenza and many animal viruses have viral envelopes covering their protein Capsids The envelopes are typically derived from portions of In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon A detergent (as a noun is a material intended to assist Cleaning. [9]

There are different genogroups of norovirus and the majority of noroviruses that infect humans are classified into genogroup G1 and G2. The genotype is the genetic constitution of a cell an organism or an individual (i [10]

Contents

History

Originally, norovirus was named after Norwalk, Ohio, where an outbreak of acute gastroenteritis occurred among children at an elementary school in November 1968. Norwalk is a city in Huron County, Ohio, United States. The population was 16238 at the 2000 census. Gastroenteritis (also known as gastro, gastric flu, and stomach flu, although unrelated to Influenza) is Inflammation of the Primary education is the first stage of Compulsory education. In 1972, immune electron microscopy on stored stool samples identified a virus, which was given the name Norwalk virus. Human Feces (also faeces &mdash see spelling differences) also known as stools, is the waste product of the human digestive system and varies significantly 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. Cloning in Biology is the process of producing populations of genetically-identical individuals that occurs in nature when organisms such as Bacteria, Insects For the sense of "sequencing" used in Electronic music, see the Music sequencer article The Caliciviridae family are a family of Viruses, members of Class IV of the Baltimore scheme. [11] The name norovirus (Norovirus for the genus) was approved by the International Committee on Taxonomy of Viruses in 2002. The International Committee on Taxonomy of Viruses ( ICTV) is a committee which authorizes and organizes the taxonomic classification of Viruses They have [12]

Common names of the illness caused by noroviruses are winter vomiting disease, viral gastroenteritis and acute non-bacterial gastroenteritis[5], also colloquially known as "stomach flu" (a broad name which can also refer to gastric inflammation caused by other viruses and bacteria). Gastroenteritis (also known as gastro, gastric flu, and stomach flu, although unrelated to Influenza) is Inflammation of the Gastroenteritis (also known as gastro, gastric flu, and stomach flu, although unrelated to Influenza) is Inflammation of the

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. PubMed is a free search engine for accessing the MEDLINE database of citations and abstracts of biomedical research articles [13]

Signs and symptoms

The disease is usually self-limiting, and characterised by nausea, vomiting, diarrhea, and abdominal pain. Nausea ( Latin: Nausea, Greek:, " Sea-sickness " also called wamble) is the sensation of unease and discomfort In Medicine, diarrhea, also spelled diarrhoea (see spelling differences) is frequent loose or liquid Bowel movements Acute diarrhea 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. Dehydration ( hypohydration) is the removal of Water ( hydro in ancient Greek) from an object [5]

Diagnosis

Specific diagnosis of norovirus is routinely made by polymerase chain reaction (PCR) assays or real-time PCR assays, which give results within a few hours. An assay is a procedure where a property or concentration of an Analyte is measured In Molecular biology, real-time polymerase chain reaction, also called quantitative real time polymerase chain reaction (qPCR or kinetic polymerase chain reaction These assays are very sensitive and can detect concentrations as low as 10 virus particles. [14]

Tests such as EIA that use antibodies against a mixture of norovirus strains are available commercially but lack specificity and sensitivity. Antibodies (also known as immunoglobulins, abbreviated Ig) are Gamma globulin Proteins that are found in Blood or other Bodily [15]

Prevention and infection control

Hand washing remains an effective method to reduce the spread of norovirus pathogens. Hand washing is the act of cleansing the Hands with Water or another Liquid, with or without the use of Soap or other Detergents A pathogen (from Greek πάθος pathos "suffering passion" and γἰγνομαι (γεν- gignomai (gen- "I give birth to" infectious Norovirus can be aerosolized when those stricken with the illness vomit. Particulates, alternatively referred to as particulate matter (PM or fine particles, are tiny particles of solid or liquid suspended in a gas Surface sanitizing is recommended in areas where the Norovirus may be present on surfaces.

In health care environments, the prevention of nosocomial infections involves routine and terminal cleaning. Nosocomial infections are Infections which are a result of treatment in a Hospital or a healthcare service unit but secondary to the patient's original condition Terminal Cleaning describes a cleaning method used in healthcare environments to control the spread of infections 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. Nonflammable alcohol vapor in CO2 (NAV-CO2 systems use Carbon dioxide (CO2 as a propellant to dispense a 56% Isopropyl alcohol solution in [16]

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 CDC study of eleven outbreaks in New York State lists the suspected mode of transmission as person-to-person in seven outbreaks, foodborne in two, waterborne in one, and one unknown. The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous In Medicine, transmission is the passing of a Disease from an infected individual or group to a previously uninfected individual or group The source of waterborne outbreaks may include water from municipal supplies, wells, recreational lakes, swimming pools and ice machines. [17]

Shellfish and salad ingredients are the foods most often implicated in Norwalk outbreaks. Shellfish is a Culinary and Fisheries term for those aquatic Invertebrate animals that are used as Food: various species of molluscs Salad is a mixture of cold foods usually including vegetables and/or fruits often with a dressing occasionally nuts or Croutons, and sometimes with the addition of Ingestion of raw or insufficiently steamed clams and oysters poses a high risk for infection with the Norwalk virus. Clam is a word which can be used for all some or only a few Species of Bivalve Mollusks the word is a Common name which has The common name oyster is used for a number of different groups of Bivalve Mollusks most of which live in marine habitats or Brackish water. Foods other than shellfish are contaminated by ill food handlers. [18]

Relative frequency of disease

Only the common cold is reported more frequently than viral gastroenteritis as a cause of illness in the U. Acute viral nasopharyngitis or acute coryza, usually known as the common cold, is a highly contagious viral Infectious disease of the 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 types B and AB confer partial protection against symptomatic infection. A blood type (also called a blood group) is a classification of Blood based on the presence or absence of inherited Antigenic substances on the [19][20]

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. Gastroenteritis (also known as gastro, gastric flu, and stomach flu, although unrelated to Influenza) is Inflammation of the [3] 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. [21]

Outbreaks

Microbiology

Classification

Transmission electron micrograph of Norovirus particles in faeces
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. [23] 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". A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Serotypes, strains and isolates include:[1]

"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. "[23]

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 genotypes. The genotype is the genetic constitution of a cell an organism or an individual (i For example genogroup II, the most prevalent human genogroup, presently contains 19 genotypes. Genogroups I, II and IV infect humans, whereas genogroup III infects bovine species and genogroup V has recently been isolated in mice. The biological Subfamily bovines includes a diverse group of 10 species of medium to large sized Ungulates including domestic Cattle, Bison, Water [24]

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. Gastroenteritis (also known as gastro, gastric flu, and stomach flu, although unrelated to Influenza) is Inflammation of the 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. Farmington Hills is an affluent as well as the most populous city in Oakland County in the U The United States of America —commonly referred to as the For a topic outline on this subject see List of basic Japan topics. Australasia is a Region of Oceania: New Zealand, Australia, Papua New Guinea, and neighbouring Islands in the Pacific In 2006 there was another large increase in NoV infection around the globe. [25] 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. [26][27][28]

Virus structure

Noroviruses contain a positive-sense RNA genome of approximately 7. Sense, when applied in a Molecular biology context is a general concept used to compare the polarity of Nucleic acid molecules such as DNA or RNA Ribonucleic acid ( RNA) is a Nucleic acid that consists of a long chain of Nucleotide units In classical genetics the genome of a Diploid Organism including Eukarya refers to a full set of chromosomes or genes in a Gamete, thereby 5 kbp, encoding a major structural protein (VP1) of about 58~60 kDa and a minor capsid protein (VP2). In Molecular biology, two Nucleotides on opposite complementary DNA or RNA strands that are connected via Hydrogen bonds are called Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express For the leaf bug see Miridae. A capsid is the protein shell of a virus. [29] The virus particles demonstrate an amorphous surface structure when visualized using electron microscopy and are between 27-38 nm in size. An electron microscope is a type of Microscope that uses Electrons to illuminate a specimen and create an enlarged image The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International [30]

References

  1. ^ a b ICTVdB Family 00. 012. Caliciviridae
  2. ^ a b Lindesmith L, Moe C, Marionneau S, et al (2003). "Human susceptibility and resistance to Norwalk virus infection". Nat. Med. 9 (5): 548–53. doi:10.1038/nm860. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 12692541.  
  3. ^ a b Norovirus: Technical Fact Sheet. National Center for Infectious Diseases, CDC.
  4. ^ Widdowson MA, Sulka A, Bulens SN, et al (2005). "Norovirus and foodborne disease, United States, 1991-2000". Emerging Infect. Dis. 11 (1): 95–102. PMID 15705329.  
  5. ^ a b c Goodgame R (2006). "Norovirus gastroenteritis". Curr Gastroenterol Rep 8 (5): 401–8. doi:10.1007/s11894-006-0026-4. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 16968608.  
  6. ^ Lindesmith L, Moe C, Lependu J, Frelinger JA, Treanor J, Baric RS (2005). "Cellular and humoral immunity following Snow Mountain virus challenge". J. Virol. 79 (5): 2900–9. doi:10.1128/JVI.79.5.2900-2909.2005. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 15709009.  
  7. ^ Noda M, Fukuda S, Nishio O (2007). "Statistical analysis of attack rate in norovirus foodborne outbreaks". Int J Food Microbiol: 216. doi:10.1016/j.ijfoodmicro.2007.11.073. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 18177970.  
  8. ^ Koopmans M, Duizer E (2004). "Foodborne viruses: an emerging problem". Int. J. Food Microbiol. 90 (1): 23–41. doi:10.1016/S0168-1605(03)00169-7. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 14672828.  
  9. ^ Jimenez L, Chiang M (2006). "Virucidal activity of a quaternary ammonium compound disinfectant against feline calicivirus: a surrogate for norovirus". Am J Infect Control 34 (5): 269–73. doi:10.1016/j.ajic.2005.11.009. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 16765204.  
  10. ^ Vinjé J, Green J, Lewis DC, Gallimore CI, Brown DW, Koopmans MP (2000). "Genetic polymorphism across regions of the three open reading frames of "Norwalk-like viruses"". Arch. Virol. 145 (2): 223–41. PMID 10752550.  
  11. ^ Kapikian AZ (1996). "Overview of viral gastroenteritis". Arch. Virol. Suppl. 12: 7–19. PMID 9015097.  
  12. ^ 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
  13. ^ Appleton H (1987). "Small round viruses: classification and role in food-borne infections". Ciba Found. Symp. 128: 108–25. PMID 3036438.  
  14. ^ Marshall JA, Bruggink LD (2006). "Laboratory diagnosis of norovirus". Clin. Lab. 52 (11-12): 571–81. PMID 17175887.  
  15. ^ Wilhelmi de Cal I, Revilla A, del Alamo JM, Román E, Moreno S, Sánchez-Fauquier A (2007). "Evaluation of two commercial enzyme immunoassays for the detection of norovirus in faecal samples from hospitalised children with sporadic acute gastroenteritis". Clin. Microbiol. Infect. 13 (3): 341–3. doi:10.1111/j.1469-0691.2006.01594.x. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 17391396.  
  16. ^ Chadwick PR, Beards G, Brown D, Caul EO, Cheesbrough J, Clarke I, Curry A, O'Brien S, Quigley K, Sellwood J, Westmoreland D (2000). "Management of hospital outbreaks of gastro-enteritis due to small roundstructured viruses". J. Hosp. Infect. 45 (1): 1–10. doi:10.1053/jhin.2000.0662. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 10833336.  
  17. ^ Hedberg CW, Osterholm MT (1993). "Outbreaks of food-borne and waterborne viral gastroenteritis". Clin. Microbiol. Rev. 6 (3): 199–210. PMID 8395330.  
  18. ^ Parashar UD, Monroe SS (2001). ""Norwalk-like viruses" as a cause of foodborne disease outbreaks". Rev. Med. Virol. 11 (4): 243–52. doi:10.1002/rmv.321. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 11479930.  
  19. ^ "Norwalk Virus Infection and Disease Is Associated with ABO Histo-Blood Group Type", The Journal of Infectious Diseases, 2002. '''''The Journal of Infectious Diseases''''' is a Peer-reviewed, Scientific journal published by the University of Chicago Press. Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.  
  20. ^ "Binding of Norwalk Virus-Like Particles to ABH Histo-Blood Group Antigens Is Blocked by Antisera from Infected Human Volunteers or Experimentally Vaccinated Mice", Journal of Virology, 2002. The Journal of Virology is an academic journal that covers research concerning Viruses using cross-disciplinary approaches including Biochemistry, Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.  
  21. ^ Shieh Y, Monroe SS, Fankhauser RL, Langlois GW, Burkhardt W, Baric RS (2000). "Detection of norwalk-like virus in shellfish implicated in illness". J. Infect. Dis. 181 Suppl 2: S360–6. PMID 10804149.  
  22. ^ Investigation Update on the Carnival Liberty. Centers for Disease Control and Prevention (CDC). The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated United States Department of Health and Human Services (25 November 2006). The United States Department of Health and Human Services ( HHS) is a Cabinet department of the United States government with the goal of protecting Events 1034 - Máel Coluim mac Cináeda, King of Scots dies Donnchad, the Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar.
  23. ^ a b Department of Health and Ageing Norovirus laboratory case definition
  24. ^ Ramirez S, Giammanco GM, De Grazia S, Colomba C, Martella V, Arista S (2008). "Genotyping of GII.4 and GIIb norovirus RT-PCR amplicons by RFLP analysis". J. Virol. Methods 147 (2): 250–6. doi:10.1016/j.jviromet.2007.09.005. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 17953996.  
  25. ^ Tu ET, Bull RA, Greening GE, Hewitt J, Lyon MJ, Marshall JA, McIver CJ, Rawlinson WD, White PA (2008). "Epidemics of gastroenteritis during 2006 were associated with the spread of norovirus GII.4 variants 2006a and 2006b". Clin. Infect. Dis. 46 (3): 413–20. doi:10.1086/525259. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 18177226.  
  26. ^ Huang P, Farkas T, Marionneau S, Zhong W, Ruvoën-Clouet N, Morrow AL, Altaye M, Pickering LK, Newburg DS, LePendu J, Jiang X (2003). "Noroviruses bind to human ABO, Lewis, and secretor histo-blood group antigens: identification of 4 distinct strain-specific patterns". J. Infect. Dis. 188 (1): 19–31. doi:10.1086/375742. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 12825167.  
  27. ^ Huang P, Farkas T, Zhong W, Tan M, Thornton S, Morrow AL, Jiang X (2005). "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". J. Virol. 79 (11): 6714–22. doi:10.1128/JVI.79.11.6714-6722.2005. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 15890909.  
  28. ^ Rockx BH, Vennema H, Hoebe CJ, Duizer E, Koopmans MP (2005). "Association of histo-blood group antigens and susceptibility to norovirus infections". J. Infect. Dis. 191 (5): 749–54. doi:10.1086/427779. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 15688291.  
  29. ^ Clarke IN, Lambden PR (2000). "Organization and expression of calicivirus genes". J. Infect. Dis. 181 Suppl 2: S309–16. PMID 10804143.  
  30. ^ Prasad BV, Crawford S, Lawton JA, Pesavento J, Hardy M, Estes MK (2001). "Structural studies on gastroenteritis viruses". Novartis Found. Symp. 238: 26–37; discussion 37–46. PMID 11444031.  

External links

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Dictionary

norovirus

-noun

  1. (virology) The genus of number of species of virus, family Caliciviridae, causing human gastroenteritis, of which Norwalk virus is the protype.
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