Norovirus Explained
Norovirus, also known as Norwalk virus and sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis.[1] [2] Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain.[3] Fever or headaches may also occur.[3] Symptoms usually develop 12 to 48 hours after being exposed, and recovery typically occurs within one to three days.[3] Complications are uncommon, but may include dehydration, especially in the young, the old, and those with other health problems.[3]
The virus is usually spread by the fecal–oral route. This may be through contaminated food or water or person-to-person contact. It may also spread via contaminated surfaces or through air from the vomit of an infected person. Risk factors include unsanitary food preparation and sharing close quarters. Diagnosis is generally based on symptoms.[4] Confirmatory testing is not usually available but may be performed by public health agencies during outbreaks.[4]
Prevention involves proper hand washing and disinfection of contaminated surfaces.[5] There is no vaccine or specific treatment for norovirus.[5] [6] Management involves supportive care such as drinking sufficient fluids or intravenous fluids.[6] Oral rehydration solutions are the preferred fluids to drink, although other drinks without caffeine or alcohol can help.[6] Alcohol-based hand sanitizers are not effective against the norovirus, according to the NHS information page on the subject;[7] this is due to norovirus being a non-enveloped virus.
Norovirus results in about 685 million cases of disease and 200,000 deaths globally a year.[2] [8] It is common both in the developed and developing world.[4] [9] Those under the age of five are most often affected, and in this group it results in about 50,000 deaths in the developing world.[2] Norovirus infections occur more commonly during winter months.[2] It often occurs in outbreaks, especially among those living in close quarters.[4] In the United States, it is the cause of about half of all foodborne disease outbreaks.[4] The virus is named after the city of Norwalk, Ohio, US, where an outbreak occurred in 1968.[10]
Signs and symptoms
Norovirus infection is characterized by nausea, vomiting, watery diarrhea, abdominal pain, and in some cases, loss of taste. A person usually develops symptoms of gastroenteritis 12 to 48 hours after being exposed to norovirus.[11] General lethargy, weakness, muscle aches, headaches, and low-grade fevers may occur. The disease is usually self-limiting, and severe illness is rare. Although having norovirus can be unpleasant, it is not usually dangerous, and most who contract it make a full recovery within two to three days.[1]
Norovirus can establish a long-term infection in people who are immunocompromised, such as those with common variable immunodeficiency or with a suppressed immune system after organ transplantation. These infections can be with or without symptoms. In severe cases, persistent infections can lead to norovirus‐associated enteropathy, intestinal villous atrophy, and malabsorption.[12]
Virology
Transmission
Noroviruses are transmitted directly from person to person (62–84% of all reported outbreaks)[13] and indirectly via contaminated water and food. They are extremely contagious, and fewer than twenty virus particles can cause an infection[14] (some research suggests as few as five).[15] Transmission can be aerosolized when those stricken with the illness vomit or by a toilet flush when vomit or diarrhea is present; infection can follow eating food or breathing air near an episode of vomiting, even if cleaned up.[16] The viruses continue to be shed after symptoms have subsided, and shedding can still be detected many weeks after infection.[17]
Vomiting, in particular, transmits infection effectively and appears to allow airborne transmission. In one incident, a person who vomited spread the infection across a restaurant, suggesting that many unexplained cases of food poisoning may have their source in vomit.[18] In December 1998, 126 people were dining at six tables; one person vomited onto the floor. Staff quickly cleaned up, and people continued eating. Three days later others started falling ill; 52 people reported a range of symptoms, from fever and nausea to vomiting and diarrhea. The cause was not immediately identified. Researchers plotted the seating arrangement: more than 90% of the people at the same table as the sick person later reported becoming ill. There was a direct correlation between the risk of infection of people at other tables and how close they were to the sick person. More than 70% of the diners at an adjacent table fell ill; at a table on the other side of the restaurant, the infection rate was still 25%. The outbreak was attributed to a Norwalk-like virus (norovirus). Other cases of transmission by vomit were later identified.[19]
In one outbreak at an international scout jamboree in the Netherlands, each person with gastroenteritis infected an average of 14 people before increased hygiene measures were put in place. Even after these new measures were enacted, an ill person still infected an average of 2.1 other people.[20] A US Centers for Disease Control and Prevention (CDC) study of 11 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 source of waterborne outbreaks may include water from municipal supplies, wells, recreational lakes, swimming pools, and ice machines.[21]
Shellfish and salad ingredients are the foods most often implicated in norovirus outbreaks. Ingestion of shellfish that has not been sufficiently heatedunder poses a high risk for norovirus infection.[22] [23] Foods other than shellfish may be contaminated by infected food handlers.[24] Many norovirus outbreaks have been traced to food that was handled by only one infected person.[25]
Between March and August 2017, in Quebec, Canada, there was an outbreak of norovirus that sickened more than 700 people. According to an investigation by Canada's CFIA Food Control Agency, the culprit was frozen raspberries imported from Harbin Gaotai Food Co Ltd, a Chinese supplier, and then Canadian authorities issued a recall on raspberries products from Harbin Gaotai.[26]
According to the CDC, there was a surge in norovirus cases on thirteen cruise ships in 2023, which marks the highest number of outbreaks since 2012.[27]
Classification
Noroviruses (NoV) are a genetically diverse group of single-stranded positive-sense RNA, non-enveloped viruses belonging to the family Caliciviridae.[28] [29] According to the International Committee on Taxonomy of Viruses, the genus Norovirus has one species, which is called Norwalk virus.[28]
Noroviruses can genetically be classified into at least seven different genogroups (GI, GII, GIII, GIV, GV, GVI, and GVII), which can be further divided into other genetic clusters or genotypes.[30]
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.[29]
Most noroviruses that infect humans belong to genogroups GI and GII.[31] 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.[32]
Recent examples include US95/96-US strain, associated with global outbreaks in the mid- to late-1990s; Farmington Hills virus associated with outbreaks in Europe and the United States in 2002 and in 2004; and Hunter virus which was associated with outbreaks in Europe, Japan, and Australasia. In 2006, there was another large increase in NoV infection around the globe.[33] Reports have shown a link between the expression of human histo-blood group antigens (HBGAs) and the susceptibility to norovirus infection. Studies have suggested the capsid of noroviruses may have evolved from selective pressure of human HBGAs.[34] HBGAs are not, however, the receptor or facilitator of norovirus infection. In fact, co-factors such as bile salts may facilitate the infection, making it more intense when introduced during or after the initial infection of the host tissue.[35] Bile salts are produced by the liver in response to eating fatty foods, and they help with the absorption of consumed lipids. It is not yet clear as to at what specific point in the Norovirus replication cycle bile salts facilitate infection: penetration, uncoating, or maintaining capsid stability.
The protein MDA-5 may be the primary immune sensor that detects the presence of noroviruses in the body.[36] Some people have common variations of the MDA-5 gene that could make them more susceptible to norovirus infection.[37]
Structure
Genus | Structure | Symmetry ! | Capsid | Genomic arrangement | Genomic segmentation |
---|
Norovirus | Icosahedral | T=1, T=3 | Non-enveloped | Linear | Monopartite | |
Viruses in Norovirus are non-enveloped, with icosahedral geometries. Capsid diameters vary widely, from 23 to 40 nm in diameter. The larger capsids (38–40 nm) exhibit T=3 symmetry and are composed of 180 VP1 proteins. Small capsids (23 nm) show T=1 symmetry, and are composed of 60 VP1 proteins.[38] The virus particles demonstrate an amorphous surface structure when visualized using electron microscopy.[39]
Genome
Noroviruses contain a linear, non-segmented, positive-sense RNA genome of approximately 7.5 kilobases, encoding a large polyprotein which is cleaved into six smaller non-structural proteins (NS1/2 to NS7)[40] by the viral 3C-like protease (NS6), a major structural protein (VP1) of about 58~60 kDa and a minor capsid protein (VP2).[41]
The most variable region of the viral capsid is the P2 domain, which contains antigen-presenting sites and carbohydrate-receptor binding regions.[42] [43] [44] [45] [46]
Evolution
Groups 1, 2, 3, and 4 last shared a common ancestor in AD 867.[47] The group 2 and group 4 viruses last shared a common ancestor in approximately AD 1443 (95% highest posterior density AD 1336–1542).[48] Several estimates of the evolution rate have been made varying from 8.98 × 10−3 to 2.03 × 10−3 substitutions per site per year.
The estimated mutation rate (1.21 to 1.41 substitutions per site per year) in this virus is high even compared with other RNA viruses.[49]
In addition, a recombination hotspot exists at the ORF1-ORF2 (VP1) junction.[50]
Replication cycle
Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment to host receptors, which mediates endocytosis. Positive-stranded RNA virus transcription is the method of replication. Translation takes place by leaky scanning and RNA termination-reinitiation. Humans and other mammals serve as the natural host. Transmission routes are fecal-oral and contamination.
Pathophysiology
When a person becomes infected with norovirus, the virus replicates within the small intestine. The principal symptom is acute gastroenteritis, characterized by nausea, forceful vomiting, watery diarrhea, and abdominal pain, that develops between 12 and 48 hours after exposure, and lasts for 24–72 hours.[51] Sometimes there is loss of taste, general lethargy, weakness, muscle aches, headache, cough, and/or low-grade fever. The disease is usually self-limiting.
Severe illness is rare; although people are frequently treated at the emergency ward, they are rarely admitted to the hospital. The number of deaths from norovirus in the United States is estimated to be around 570–800[52] each year, with most of these occurring in the very young, the elderly, and persons with weakened immune systems. Symptoms may become life-threatening in these groups if dehydration or electrolyte imbalance is ignored or left untreated.[53]
Diagnosis
Specific diagnosis of norovirus is routinely made by polymerase chain reaction (PCR) assays or quantitative PCR assays, which give results within a few hours. These assays are very sensitive and can detect as few as 10 virus particles.[54] Tests such as ELISA that use antibodies against a mixture of norovirus strains are available commercially, but lack specificity and sensitivity.[55]
Prevention
After infection, immunity to the same strain of the virus – the genotype – protects against reinfection for between six months to two years.[56] This immunity does not fully protect against infection with the other diverse genotypes of the virus.[56]
In Canada, norovirus is a notifiable disease.[57] In both the US and the UK it is not notifiable.[58] [59]
Hand washing and disinfectants
Hand washing with soap and water is an effective method for reducing the transmission of norovirus pathogens. Alcohol rubs (≥62% isopropyl alcohol) may be used as an adjunct, but are less effective than hand-washing, as norovirus lacks a lipid viral envelope.[60] Surfaces where norovirus particles may be present can be sanitised with a solution of 1.5% to 7.5% of household bleach in water, or other disinfectants effective against norovirus.[51] [61] [62]
Health care facilities
In healthcare environments, the prevention of nosocomial infections involves routine and terminal cleaning. Nonflammable alcohol vapor in CO2 systems is used in health care environments where medical electronics would be adversely affected by aerosolized chlorine or other caustic compounds.[63]
In 2011, the CDC published a clinical practice guideline addressing strategies for the prevention and control of norovirus gastroenteritis outbreaks in healthcare settings.[64] [65] Based on a systematic review of published scientific studies, the guideline presents 51 specific evidence-based recommendations, which were organized into 12 categories: 1) patient cohorting and isolation precautions, 2) hand hygiene, 3) patient transfer and ward closure, 4) food handlers in healthcare, 5) diagnostics, 6) personal protective equipment, 7) environmental cleaning, 8) staff leave and policy, 9) visitors, 10) education, 11) active case-finding, and 12) communication and notification. The guideline also identifies eight high-priority recommendations and suggests several areas in need of future research.
Vaccine trials
LigoCyte announced in 2007 that it was working on a vaccine and had started phase 1 trials.[66] The company has since been taken over by Takeda Pharmaceutical Company.[67], a bivalent (NoV GI.1/GII.4) intramuscular vaccine had completed phase 1 trials.[68] [69] In 2020 the phase 2b trials were finished.[70] [71] The vaccine relies on using a virus-like particle that is made of the norovirus capsid proteins in order to mimic the external structure of the virus. Since there is no RNA in this particle, it is incapable of reproducing and cannot cause an infection.[66]
Persistence
The norovirus can survive for long periods outside a human host depending on the surface and temperature conditions: it can survive for weeks on hard and soft surfaces,[72] and it can survive for months, maybe even years in contaminated still water.[73] A 2006 study found the virus remained on surfaces used for food preparation seven days after contamination.[74]
Detection in food
Routine protocols to detect norovirus in clams and oysters by reverse transcription polymerase chain reaction are being employed by governmental laboratories such as the Food and Drug Administration (FDA) in the US.[75]
Treatment
There is no specific medicine to treat people with norovirus illness. Norovirus infection cannot be treated with antibiotics because it is a virus. Treatments aim to avoid complications by measures such as the management of dehydration caused by fluid loss in vomiting and diarrhea,[6] and to mitigate symptoms using antiemetics and antidiarrheals.[76]
Epidemiology
Norovirus causes about 18% of all cases of acute gastroenteritis worldwide. It is relatively common in developed countries and in low-mortality developing countries (20% and 19% respectively) compared to high-mortality developing countries (14%). Proportionately it causes more illness in people in the community or in hospital outpatients (24% and 20% respectively) as compared with hospital inpatients (17%) in whom other causes are more common.[77]
Age and emergence of new norovirus strains do not appear to affect the proportion of gastroenteritis attributable to norovirus.[77]
In the United States, the estimated annual number of norovirus cases was 21 million, representing a rate of 6,270 cases per 100,000 individuals.
Norovirus is a common cause of epidemics of gastroenteritis on cruise ships. The CDC, through its Vessel Sanitation Program, records and investigates outbreaks of gastrointestinal illness – mostly caused by norovirus – on cruise ships with both a US and foreign itinerary;[78] there were 12 in 2015, and 10 from 1 January to 9 May 2016. An outbreak may affect over 25% of passengers, and a smaller proportion of crew members.[79]
Human genetics
Epidemiological studies have shown that individuals with different ABO(H) (histo-blood group) phenotypes are infected with NoV strains in a genotype-specific manner.[80] GII.4 includes global epidemic strains and binds to more histo-blood group antigens than other genogroups. FUT2 fucosyltransferase transfers a fucose sugar to the end of the ABO(H) precursor in gastrointestinal cells and saliva glands. The ABH-antigen produced is thought to act as a receptor for human norovirus: A non-functional fucosyltransferase FUT2 provides high protection from the most common norovirus strain, GII.4.[81]
Homozygous carriers of any nonsense mutation in the FUT2 gene are called non-secretors, as no ABH-antigen is produced. Approximately 20% of Caucasians are non-secretors due to G428A and C571T nonsense mutations in FUT2 and therefore have strong – although not absolute – protection from the norovirus GII.4.[82] Non-secretors can still produce ABH antigens in erythrocytes, as the precursor is formed by FUT1.[83] Some norovirus genotypes (GI.3) can infect non-secretors.[84]
History
The norovirus was originally named the "Norwalk agent" after Norwalk, Ohio, in the United States, where an outbreak of acute gastroenteritis occurred among children at Bronson Elementary School in November 1968. In 1972, electron microscopy on stored human 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.[85] The name "norovirus" (Norovirus for the genus) was approved by the International Committee on Taxonomy of Viruses (ICTV) in 2002.[86] In 2011, however, a press release and a newsletter was published by ICTV, which strongly encouraged the media, national health authorities, and the scientific community to use the virus name Norwalk virus, rather than the genus name Norovirus when referring to outbreaks of the disease. This was also a public response by ICTV to the request from an individual in Japan to rename the Norovirus genus because of the possibility of negative associations for people in Japan and elsewhere who have the family name "Noro". Before this position of ICTV was made public, ICTV consulted widely with members of the Caliciviridae Study Group and carefully discussed the case.[87]
In addition to "Norwalk agent" and "Norwalk virus", the virus has also been called "Norwalk-like virus", "small, round-structured viruses" (SRSVs), Spencer flu, and "Snow Mountain virus".[88] Common names of the illness caused by noroviruses still in use include "Roskilde illness", "winter vomiting disease",[89] "winter vomiting bug",[90] [91] "viral gastroenteritis", and "acute nonbacterial gastroenteritis".[53]
See also
External links
Notes and References
- Web site: Norovirus (vomiting bug) . nhs.uk . 8 June 2018 . 2017-10-19 . 2018-06-12 . https://web.archive.org/web/20180612143424/https://www.nhs.uk/conditions/norovirus/ . live .
- Web site: Norovirus Worldwide. CDC. 29 December 2017. en-us. 15 December 2017. https://web.archive.org/web/20181207142756/https://www.cdc.gov/norovirus/worldwide.html. 7 December 2018. dead.
- Web site: Norovirus Symptoms. CDC. 29 December 2017. en-us. 24 June 2016. https://web.archive.org/web/20181206210732/https://www.cdc.gov/norovirus/about/symptoms.html. 6 December 2018. dead.
- Book: Brunette . Gary W. . vanc . CDC Yellow Book 2018: Health Information for International Travel . 2017 . Oxford University Press . 9780190628611 . 269 . 2020-09-05 . 2022-10-07 . https://web.archive.org/web/20221007190854/https://books.google.com/books?id=np6PDgAAQBAJ&pg=PA269 . live .
- Web site: Preventing Norovirus Infection. CDC. 29 December 2017. en-us. 5 May 2017. 9 December 2017. https://web.archive.org/web/20171209085135/https://www.cdc.gov/norovirus/preventing-infection.html. live.
- Web site: Norovirus – Treatment. CDC. 29 December 2017. 22 December 2017. https://web.archive.org/web/20171222151627/https://www.cdc.gov/norovirus/about/treatment.html. live.
- Web site: 2017-10-19. Norovirus (vomiting bug). 2021-05-29. nhs.uk. en. 2018-06-12. https://web.archive.org/web/20180612143424/https://www.nhs.uk/conditions/norovirus/. live.
- Web site: Global Burden of Norovirus and Prospects for Vaccine Development. CDC. 29 December 2017. 3. August 2015. 29 December 2017. https://web.archive.org/web/20171229231709/https://www.cdc.gov/norovirus/downloads/global-burden-report.pdf. live.
- Nguyen GT, Phan K, Teng I, Pu J, Watanabe T . A systematic review and meta-analysis of the prevalence of norovirus in cases of gastroenteritis in developing countries . Medicine . 96 . 40 . e8139 . October 2017 . 28984764 . 5738000 . 10.1097/MD.0000000000008139 .
- Book: Vesikari, Timo . Vesikari . Timo . Damme . Pierre Van . Pediatric Vaccines and Vaccinations: A European Textbook . 2021 . Springer . Second. Switzerland . 978-3-030-77172-0 . 289–292 . 25. Norovirus vaccines in pipeline development. https://books.google.com/books?id=LLg-EAAAQBAJ&pg=PA289. en.
- Web site: Norovirus Clinical Overview CDC. www.cdc.gov. 2016-03-28. 2016-03-17. https://web.archive.org/web/20160317184010/http://www.cdc.gov/norovirus/hcp/clinical-overview.html. live.
- Bok . K . Green . K. Y. . Norovirus Gastroenteritis in Immunocompromised Patients . New England Journal of Medicine . 368 . 10 . 971 . 2013-03-16 . 23465122 . 4793940 . 10.1056/NEJMc1301022.
- Moore MD, Goulter RM, Jaykus L . Human Norovirus as a Foodborne Pathogen: Challenges and Developments . Annual Review of Food Science and Technology . 6 . 1 . 411–33 . April 2015 . 10.1146/annurev-food-022814-015643 . 25884284. free .
- Morillo SG, Timenetsky Mdo C . Norovirus: an overview . Revista da Associação Médica Brasileira . 57 . 4 . 453–8 . 2011 . 21876931 . 10.1590/s0104-42302011000400023 . free .
- Book: Leon, Juan. Immunity Against Mucosal Pathogens. Vajdy. Michael. 2008. Chapter 9. 232. Springer. https://books.google.com/books?id=0ZYFRep6EykC&pg=PA219. 978-1-4020-8412-6. 2022-10-07. 2022-10-07. https://web.archive.org/web/20221007190855/https://books.google.com/books?id=0ZYFRep6EykC&pg=PA219. live.
- Web site: I've lost my appetite.... Robert Matthews. New Scientist. 21 February 2016. 3 May 2015. https://web.archive.org/web/20150503052554/http://www.newscientist.com/article/mg16722551.000-ive-lost-my-appetite.html. live.
- Atmar RL, Opekun AR, Gilger MA, Estes MK, Crawford SE, Neill FH, Graham DY . Norwalk Virus Shedding after Experimental Human Infection . Emerg. Infect. Dis. . 14 . 10 . 1553–7 . October 2008 . 18826818 . 2609865 . 10.3201/eid1410.080117 . vanc .
- Marks PJ, Vipond IB, Carlisle D, Deakin D, Fey RE, Caul EO . Evidence for airborne transmission of Norwalk-like virus (NLV) in a hotel restaurant . Epidemiol. Infect. . 124 . 3 . 481–487 . June 2000 . 10982072 . 2810934 . 10.1017/s0950268899003805 . 10.1.1.404.2721 .
- Marks PJ, Vipond IB, Regan FM, Wedgwood K, Fey RE, Caul EO . A school outbreak of Norwalk-like virus: evidence for airborne transmission . Epidemiol. Infect. . 131 . 1 . 727–736 . August 2003 . 12948373 . 2870014 . 10.1017/s0950268803008689 .
- Heijne JC, Teunis P, Morroy G, Wijkmans C, Oostveen S, Duizer E, Kretzschmar M, Wallinga J . Enhanced Hygiene Measures and Norovirus Transmission during an Outbreak . Emerg. Infect. Dis. . 15 . 1 . 24–30 . 2009 . 19116045 . 2660689 . 10.3201/eid1501.080299 .
- Hedberg CW, Osterholm MT . Outbreaks of food-borne and waterborne viral gastroenteritis . Clin. Microbiol. Rev. . 6 . 3 . 199–210 . 1993 . 8395330 . 358282 . 10.1128/CMR.6.3.199 .
- Web site: Safe Internal Cooking Temperatures Chart . 7 May 2015 . Government of Canada . 27 December 2017 . 27 December 2017 . https://web.archive.org/web/20171227122625/https://www.canada.ca/en/health-canada/services/general-food-safety-tips/safe-internal-cooking-temperatures-chart.html . live .
- Web site: HPA: Shellfish consumption and the risk of norovirus infection. http://webarchive.nationalarchives.gov.uk/20140714084352/http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/Norovirus/oysterconsumptionnorovirus/. dead. 14 July 2014. 21 February 2016.
- Parashar UD, Monroe SS . 'Norwalk-like viruses' as a cause of foodborne disease outbreaks . Rev. Med. Virol. . 11 . 4 . 243–52 . 2001 . 11479930 . 10.1002/rmv.321 . 9922865 . 2020-09-05 . 2020-10-31 . https://web.archive.org/web/20201031083507/https://zenodo.org/record/1229350 . live .
- Koopmans M, Duizer E . Foodborne viruses: an emerging problem . Int. J. Food Microbiol. . 90 . 1 . 23–41 . 2004 . 14672828 . 10.1016/S0168-1605(03)00169-7 . 7127053 .
- Web site: Sherwood . Dave . How a Chilean raspberry scam dodged food safety controls from China to Canada . Reuters . 10 October 2020 . https://web.archive.org/web/20201010080047/https://www.reuters.com/article/chile-crime-raspberries-insight/how-a-chilean-raspberry-scam-dodged-food-safety-controls-from-china-to-canada-idUSKBN26R1M1 . 10 October 2020 . dead .
- Web site: Cruise ships are seeing the highest number of norovirus outbreaks in a decade . 15 July 2023 . Deseret News. 13 July 2023 .
- Web site: Family: Caliciviridae | ICTV. www.ictv.global. 2019-10-02. 2021-08-29. https://web.archive.org/web/20210829153617/https://talk.ictvonline.org/ictv-reports/ictv_online_report/positive-sense-rna-viruses/w/caliciviridae. live.
- Web site: Public Health Laboratory Network . Norovirus Laboratory Case Definition (LCD) . Australian Government Department of Health and Ageing . en . 25 September 2006 . 15 September 2020 . 1 May 2008 . https://web.archive.org/web/20080501230732/http://www.health.gov.au/internet/main/publishing.nsf/Content/cda-phlncd-norwalk.htm . live .
- Atmar . Robert L . Baehner . Frank . Cramer . Jakob P . Lloyd . Eric . Sherwood . James . Borkowski . Astrid . Mendelman . Paul M . Al-Ibrahim . Mohamed S . Bernstein . David L . Brandon . Donald M . Chu . Laurence . Davis . Matthew G . Epstein . Robert J . Frey . Sharon E . Rosen . Jeffrey B . Treanor . John J . Persistence of Antibodies to 2 Virus-Like Particle Norovirus Vaccine Candidate Formulations in Healthy Adults: 1-Year Follow-up With Memory Probe Vaccination . The Journal of Infectious Diseases . 15 August 2019 . 220 . 4 . 603–614 . 10.1093/infdis/jiz170. 31001633 .
- Vinjé J, Green J, Lewis DC, Gallimore CI, Brown DW, Koopmans MP . Genetic polymorphism across regions of the three open reading frames of "Norwalk-like viruses" . Arch. Virol. . 145 . 2 . 223–41 . 2000 . 10752550 . 10.1007/s007050050020 . 20525287 .
- Noel JS, Fankhauser RL, Ando T, Monroe SS, Glass RI . Identification of a distinct common strain of "Norwalk-like viruses" having a global distribution . J. Infect. Dis. . 179 . 6 . 1334–44 . 2000 . 10228052 . 10.1086/314783 . free .
- Tu ET, Bull RA, Greening GE, Hewitt J, Lyon MJ, Marshall JA, McIver CJ, Rawlinson WD, White PA . 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 . 2008 . 18177226 . 10.1086/525259 . 27972379 .
- Shirato H . Norovirus and histo-blood group antigens . Japanese Journal of Infectious Diseases . 64 . 2 . 95–103 . 2011 . 10.7883/yoken.64.95 . 21519121 . free .
- Graziano. Vincent R.. Wei. Jin. Wilen. Craig B.. 30 May 2019. Norovirus Attachment and Entry. Viruses. en. 11. 6. 495. 10.3390/v11060495. 31151248. 6630345. free.
- McCartney SA, Thackray LB, Gitlin L, Gilfillan S, Virgin HW, Virgin Iv HW, Colonna M . MDA-5 Recognition of a Murine Norovirus . PLOS Pathog . 4 . 7 . e1000108 . July 18, 2008 . 18636103 . 2443291 . 10.1371/journal.ppat.1000108 . Baric RS . free .
- http://newswise.com/articles/view/542714/ Researchers Discover Primary Sensor That Detects Stomach Viruses
- Web site: Viral Zone. ExPASy. 15 June 2015. 9 January 2017. https://web.archive.org/web/20170109200451/http://viralzone.expasy.org/all_by_species/194.html. live.
- Book: Prasad BV, Crawford S, Lawton JA, Pesavento J, Hardy M, Estes MK . Gastroenteritis Viruses . Structural Studies on Gastroenteritis Viruses . 238 . 26–37; discussion 37–46 . 2001 . 11444031 . 10.1002/0470846534.ch3 . 978-0-470-84653-7 . Novartis Foundation Symposia .
- Thorne LG, Goodfellow IG . Norovirus gene expression and replication . The Journal of General Virology . 95 . Pt 2 . 278–91 . February 2014 . 24243731 . 10.1099/vir.0.059634-0 . free .
- Clarke IN, Lambden PR . Organization and expression of calicivirus genes . The Journal of Infectious Diseases . 181 . S309-16 . May 2000 . Suppl 2 . 10804143 . 10.1086/315575 . free .
- Tan M, Hegde RS, Jiang X . The P Domain of Norovirus Capsid Protein Forms Dimer and Binds to Histo-Blood Group Antigen Receptors . J. Virol. . 78 . 12 . 6233–42 . 2004 . 15163716 . 416535 . 10.1128/JVI.78.12.6233-6242.2004 .
- Tan M, Huang P, Meller J, Zhong W, Farkas T, Jiang X . Mutations within the P2 domain of norovirus capsid affect binding to human histo-blood group antigens: evidence for a binding pocket . J. Virol. . 77 . 23 . 12562–71 . 2003 . 14610179 . 262557 . 10.1128/jvi.77.23.12562-12571.2003. Erratum . J. Virol. . 78 . 6 . 3200 . 2004. 10.1128/JVI.78.6.3201.2004 . Tan M. 10.1.1.212.5257. 220476008 .
- Cao S, Lou Z, Tan M, Chen Y, Liu Y, Zhang Z, Zhang XC, Jiang X, Li X, Rao Z . Structural Basis for the Recognition of Blood Group Trisaccharides by Norovirus . J. Virol. . 81 . 11 . 5949–57 . 2007 . 17392366 . 1900264 . 10.1128/JVI.00219-07 .
- Lundborg M, Ali E, Widmalm G . An in silico virtual screening study for the design of norovirus inhibitors: fragment-based molecular docking and binding free energy calculations . Carbohydr. Res. . 378 . 133–8 . 2013 . 23582100 . 10.1016/j.carres.2013.03.012 . 9941188 . https://web.archive.org/web/20210829153644/https://su.diva-portal.org/smash/get/diva2:656620/FULLTEXT01.pdf . 2019-06-24 . 2021-08-29 . live .
- Ali ES, Rajapaksha H, Jillian MC, Petrovsky N . Norovirus drug candidates that inhibit viral capsid attachment to human histo-blood group antigens . Antiviral Res. . 133 . 14–22 . 2016 . 27421712 . 10.1016/j.antiviral.2016.07.006 . 5026924.
- 10.1038/srep29400 . Molecular evolution of the capsid gene in human norovirus genogroup II . 2016 . Kobayashi . Miho . Matsushima . Yuki . Motoya . Takumi . Sakon . Naomi . Shigemoto . Naoki . Okamoto-Nakagawa . Reiko . Nishimura . Koichi . Yamashita . Yasutaka . Kuroda . Makoto . Saruki . Nobuhiro . Ryo . Akihide . Saraya . Takeshi . Morita . Yukio . Shirabe . Komei . Ishikawa . Mariko . Takahashi . Tomoko . Shinomiya . Hiroto . Okabe . Nobuhiko . Nagasawa . Koo . Suzuki . Yoshiyuki . Katayama . Kazuhiko . Kimura . Hirokazu . Scientific Reports . 6 . 29400 . 27384324 . 4935990 . 2016NatSR...629400K .
- 10.3389/fmicb.2018.03070 . free . Molecular Evolutionary Analyses of the RNA-Dependent RNA Polymerase Region in Norovirus Genogroup II . 2018 . Ozaki . Keita . Matsushima . Yuki . Nagasawa . Koo . Motoya . Takumi . Ryo . Akihide . Kuroda . Makoto . Katayama . Kazuhiko . Kimura . Hirokazu . Frontiers in Microbiology . 9 . 3070 . 30619155 . 6305289 .
- Victoria M, Miagostovich MP, Ferreira MS, Vieira CB, Fioretti JM, Leite JP, Colina R, Cristina J . Bayesian coalescent inference reveals high evolutionary rates and expansion of Norovirus populations . Infect Genet Evol . 9 . 5 . 927–932 . 2009 . 19559104 . 10.1016/j.meegid.2009.06.014 . free . 2009InfGE...9..927V .
- Tsimpidis M, Bachoumis G, Mimouli K, Kyriakopoulou Z, Robertson DL, Markoulatos P, Amoutzias GD . T-RECs: rapid and large-scale detection of recombination events among different evolutionary lineages of viral genomes . BMC Bioinformatics . 18 . 1 . 13 . January 2017 . 28056784 . 5216575 . 10.1186/s12859-016-1420-z . free .
- Web site: Norovirus: Technical Fact Sheet . National Center for Infectious Diseases, CDC . dead . https://web.archive.org/web/20120308152422/http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus-factsheet.htm . 2012-03-08 .
- Hall AJ, Lopman BA, Payne DC, Patel MM, Gastañaduy PA, Vinjé J, Parashar UD . Norovirus disease in the United States . Emerging Infectious Diseases . 19 . 8 . 1198–205 . August 2013 . 23876403 . 3739528 . 10.3201/eid1908.130465 .
- Goodgame R . Norovirus gastroenteritis . Current Gastroenterology Reports . 8 . 5 . 401–8 . October 2006 . 16968608 . 10.1007/s11894-006-0026-4 . 54521495 .
- Marshall JA, Bruggink LD . Laboratory diagnosis of norovirus . . 52 . 11–12 . 571–81 . 2006 . 17175887 .
- Wilhelmi de Cal I, Revilla A, del Alamo JM, Román E, Moreno S, Sánchez-Fauquier A . 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 . 2007 . 17391396 . 10.1111/j.1469-0691.2006.01594.x . free .
- Payne DC, Parashar UD, Lopman BA . Developments in understanding acquired immunity and innate susceptibility to norovirus and rotavirus gastroenteritis in children . Current Opinion in Pediatrics . 27 . 1 . 105–9 . February 2015 . 25490691 . 4618547 . 10.1097/MOP.0000000000000166 .
- Web site: Diseases Under National Surveillance (as of January 2009) . Public Health Agency of Canada . 21 November 2017 . 2003-09-17 . 2017-09-23 . https://web.archive.org/web/20170923142027/http://www.phac-aspc.gc.ca/bid-bmi/dsd-dsm/duns-eng.php . live .
- Web site: Anonymous. Notifiable diseases and causative organisms: how to report – GOV.UK. www.gov.uk. Public Health England. 26 November 2017. en. 1 May 2010. 17 July 2018. https://web.archive.org/web/20180717024817/https://www.gov.uk/guidance/notifiable-diseases-and-causative-organisms-how-to-report. live.
- Web site: Anonymous. Norovirus Reporting and Surveillance CDC. www.cdc.gov. Centers for Disease Control and Prevention. 26 November 2017. en-us. 28 December 2016. 9 December 2017. https://web.archive.org/web/20171209145710/https://www.cdc.gov/norovirus/reporting/index.html. live.
- Jimenez L, Chiang M . Virucidal activity of a quaternary ammonium compound disinfectant against feline calicivirus: a surrogate for norovirus . Am J Infect Control . 34 . 5 . 269–73 . 2006 . 16765204 . 10.1016/j.ajic.2005.11.009 .
- Web site: List G: EPA Registered Hospital Disinfectants Effective Against Norovirus (Norwalk-like virus). US Environmental Protection Agency. 9 May 2016. 2015-09-28. 2016-04-15. https://web.archive.org/web/20160415170327/https://www.epa.gov/pesticide-registration/list-g-epa-registered-hospital-disinfectants-effective-against-norovirus. live.
- Web site: Gastroenteritis and Noroviruses—Dr Jim Grey, Health Protection Agency . The Naked Scientists . 2007-12-09 . 2014-02-09 . 2014-03-31 . https://web.archive.org/web/20140331051859/http://www.thenakedscientists.com/HTML/content/interviews/interview/838/ . live .
- Chadwick PR, Beards G, Brown D, Caul EO, Cheesbrough J, Clarke I, Curry A, O'Brien S, Quigley K, Sellwood J, Westmoreland D . Management of hospital outbreaks of gastroenteritis due to small round structured viruses . J. Hosp. Infect. . 45 . 1 . 1–10 . 2000 . 10833336 . 10.1053/jhin.2000.0662 .
- Web site: HICPAC. Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in Healthcare Settings, 2011. Healthcare Infection Control Practices Advisory Committee (HICPAC). Centers for Disease Control and Prevention (CDC). 19 March 2015. 27 March 2015. https://web.archive.org/web/20150327010357/http://www.cdc.gov/hicpac/norovirus/002_norovirus-toc.html. live.
- MacCannell T, Umscheid CA, Agarwal RK, Lee I, Kuntz G, Stevenson KB . Guideline for the prevention and control of norovirus gastroenteritis outbreaks in healthcare settings . Infection Control and Hospital Epidemiology . 32 . 10 . 939–69 . October 2011 . 21931246 . 10.1086/662025 . 27996748 .
- Web site: Norovirus Vaccine. 2008-08-26. 2008-10-02. https://web.archive.org/web/20081002175650/http://www.ligocyte.com/downloads/Noro.pdf. live.
- Web site: Takeda to Acquire LigoCyte Pharmaceuticals, Inc.. 2013-06-22. 2013-06-29. https://web.archive.org/web/20130629235039/http://www.takeda.com/news/2012/20121005_4001.html. live.
- Baehner. F.. Bogaerts. H.. Goodwin. R.. 2016-12-01. Vaccines against norovirus: state of the art trials in children and adults. Clinical Microbiology and Infection. Vaccines for Mutual Protection: Selected Proceedings from the 3rd ESCMID Conference on Vaccines. 22. S136–S139. 10.1016/j.cmi.2015.12.023. 27130672. 1198-743X. free.
- Web site: Key Products and Pipeline (FY2019 Q2 Pipeline Table). 2019. Takeda Pharmaceutical Company. 9 December 2019. 6 November 2019. https://web.archive.org/web/20191106132837/https://www.takeda.com/siteassets/system/what-we-do/research-and-development-rd-in-takeda/our-pipeline/pipeline_en_2019_q2.pdf. live.
- Web site: HilleVax Pipeline . Hillevax Pipeline . 1 October 2021 . 1 October 2021 . https://web.archive.org/web/20211001201039/https://www.hillevax.com/pipeline.html . live .
- Sherwood . J . Mendelman . PM . Lloyd . E . Liu . M . Boslego . J . Borkowski . A . Jackson . A . Faix . D . US Navy study . team. . Efficacy of an intramuscular bivalent norovirus GI.1/GII.4 virus-like particle vaccine candidate in healthy US adults. . Vaccine . 22 September 2020 . 38 . 41 . 6442–6449 . 10.1016/j.vaccine.2020.07.069 . 32878708 . free .
- Web site: How To Stay Well (When Everyone Else Is Sick) . Webmd.com . 2017-01-28 . dead . https://web.archive.org/web/20140103204322/http://www.webmd.com/cold-and-flu/features/how-to-stay-well-when-everyone-else-is-sick . 2014-01-03 .
- Web site: Misery-inducing Norovirus Can Survive for Months—Perhaps Years—in Drinking Water. Frazer J. January 17, 2012. Scientific American. February 27, 2012. March 7, 2012. https://web.archive.org/web/20120307190724/http://blogs.scientificamerican.com/artful-amoeba/2012/01/17/misery-inducing-norovirus-can-survive-for-months-perhaps-years-in-drinking-water/. live.
- D'Souza DH, Sair A, Williams K, Papafragkou E, Jean J, Moore C, Jaykus L . Persistence of caliciviruses on environmental surfaces and their transfer to food . International Journal of Food Microbiology . 108 . 1 . 84–91 . 2006 . 16473426 . 10.1016/j.ijfoodmicro.2005.10.024 .
- Shieh Y, Monroe SS, Fankhauser RL, Langlois GW, Burkhardt W, Baric RS . Detection of Norwalk-like virus in shellfish implicated in illness . J. Infect. Dis. . 181 . Suppl 2 . S360–6 . 2000 . 10804149 . 10.1086/315578 . free .
- Web site: Traveler's Diarrhea. Merck Manuals Consumer Version. 21 February 2016. 28 February 2015. https://web.archive.org/web/20150228230806/http://www.merckmanuals.com/home/digestive_disorders/gastroenteritis/travelers_diarrhea.html. live.
- Ahmed SM, Hall AJ, Robinson AE, etal . Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis . Lancet Infect Dis . 14 . 8 . 725–30 . August 2014 . 24981041 . 10.1016/S1473-3099(14)70767-4 . 8006533 . 2019-06-24 . 2020-04-03 . https://web.archive.org/web/20200403224838/https://zenodo.org/record/1260252 . live .
- Web site: CDC VSP . Vessel Sanitation Program – Outbreak Updates for International Cruise Ships . Centers for Disease Control and Prevention . 9 May 2016 . 10 May 2016 . https://web.archive.org/web/20160510060625/http://www.cdc.gov/nceh/vsp/surv/gilist.htm . live .
- Web site: CDC – Vessel Sanitation Program – Balmoral, April 16, 2016 . Cdc.gov . 9 May 2016 . 14 May 2016 . https://web.archive.org/web/20160514100616/http://www.cdc.gov/nceh/vsp/surv/outbreak/2016/april16_balmoral.htm . live .
- Le Guyader FS, Krol J, Ambert-Balay K, Ruvoen-Clouet N, Desaubliaux B, Parnaudeau S, Le Saux JC, Ponge A, Pothier P, Atmar RL, Le Pendu J . Comprehensive analysis of a norovirus-associated gastroenteritis outbreak, from the environment to the consumer . Journal of Clinical Microbiology . 48 . 3 . 915–920 . March 2010 . 20053852 . 2832421 . 10.1128/JCM.01664-09.
- Carlsson B, Kindberg E, Buesa J, Rydell GE, Lidón MF, Montava R, Abu Mallouh R, Grahn A, Rodríguez-Díaz J, Bellido J, Arnedo A, Larson G, Svensson L . The G428A nonsense mutation in FUT2 provides strong but not absolute protection against symptomatic GII.4 norovirus infection . PLOS ONE . 4 . 5 . e5593 . May 2009 . 19440360 . 2680586 . 10.1371/journal.pone.0005593 . 2009PLoSO...4.5593C. free .
- Rydell GE, Kindberg E, Larson G, Svensson L . Susceptibility to winter vomiting disease: A sweet matter . Rev. Med. Virol. . 21 . 6 . 370–382 . November 2011 . 22025362 . 10.1002/rmv.704. 6679013 .
- Shirato H . Norovirus and histo-blood group antigens . Jpn. J. Infect. Dis. . 64 . 2 . 95–103 . 2011 . 10.7883/yoken.64.95 . 21519121. free .
- Nordgren J, Kindberg E, Lindgren PE, Matussek A, Svensson L . Norovirus gastroenteritis outbreak with a secretor-independent susceptibility pattern, Sweden . Emerg. Infect. Dis. . 16 . 1 . 81–87 . January 2010 . 20031047 . 10.3201/eid1601.090633 . 2874438.
- Book: Kapikian AZ . Viral Gastroenteritis . Overview of viral gastroenteritis . Archives of Virology . 12 . 7–19 . 1996 . 9015097 . 10.1007/978-3-7091-6553-9_2. 978-3-211-82875-5 . free .
- 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
- Web site: 2011 ICTV Newsletter #9, November 2011. ICTV. November 14, 2011. December 23, 2012. July 30, 2012. https://web.archive.org/web/20120730225245/http://talk.ictvonline.org/files/ictv_documents/m/newsletters/4069.aspx. dead.
- Book: Appleton H . Ciba Foundation Symposium 128 – Novel Diarrhoea Viruses . Small Round Viruses: Classification and Role in Food-Borne Infections . Novartis Foundation Symposia . 128 . 108–25 . 1987 . 3036438 . 10.1002/9780470513460.ch7 . 9780470513460 .
- Parashar U, Quiroz ES, Mounts AW, Monroe SS, Fankhauser RL, Ando T, Noel JS, Bulens SN, Beard SR, Li JF, Bresee JS, Glass RI . 2001 . "Norwalk-Like Viruses". Public Health Consequences and Outbreak Management . MMWR. Recommendations and Reports . 50 . RR-9 . 1–18 . 15580799 . 2017-09-10 . 2017-06-06 . https://web.archive.org/web/20170606134739/https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5009a1.htm . live .
- News: Norovirus shuts wards and unit at three Sussex hospitals . . January 11, 2012 . January 20, 2012 . January 15, 2012 . https://web.archive.org/web/20120115055919/http://www.bbc.co.uk/news/uk-england-kent-16509830 . live .
- News: Norovirus at Norfolk hospitals: Disruption continues . BBC News . January 12, 2012 . January 20, 2012 . January 20, 2012 . https://web.archive.org/web/20120120172326/http://www.bbc.co.uk/news/uk-england-norfolk-16531668 . live .