Editing Norovirus (section)

== Prevention ==
After [[infection]], [[immunity (medical)|immunity]] to the ''same'' strain of the virus&nbsp;– the genotype&nbsp;– protects against reinfection for six months to two years.<ref name="pmid25490691">{{cite journal | vauthors = Payne DC, Parashar UD, Lopman BA | title = Developments in understanding acquired immunity and innate susceptibility to norovirus and rotavirus gastroenteritis in children | journal = Current Opinion in Pediatrics | volume = 27 | issue = 1 | pages = 105–9 | date = February 2015 | pmid = 25490691 | pmc = 4618547 | doi = 10.1097/MOP.0000000000000166 }}</ref> This immunity does not fully protect against infection with the other diverse genotypes of the virus.<ref name="pmid25490691"/>

In [[Canada]], norovirus is a [[notifiable disease]].<ref>{{cite web | title=Diseases Under National Surveillance (as of January 2009) | publisher=Public Health Agency of Canada | url=http://www.phac-aspc.gc.ca/bid-bmi/dsd-dsm/duns-eng.php | access-date=21 November 2017 | date=2003-09-17 | archive-date=2017-09-23 | archive-url=https://web.archive.org/web/20170923142027/http://www.phac-aspc.gc.ca/bid-bmi/dsd-dsm/duns-eng.php | url-status=live }}</ref> In both the US and the UK it is not notifiable.<ref>{{cite web|last1=Anonymous|title=Notifiable diseases and causative organisms: how to report – GOV.UK|url=https://www.gov.uk/guidance/notifiable-diseases-and-causative-organisms-how-to-report|website=www.gov.uk|publisher=[[Public Health England]]|access-date=26 November 2017|language=en|date=1 May 2010|archive-date=17 July 2018|archive-url=https://web.archive.org/web/20180717024817/https://www.gov.uk/guidance/notifiable-diseases-and-causative-organisms-how-to-report|url-status=live}}</ref><ref>{{cite web|last1=Anonymous|title=Norovirus {{!}} Reporting and Surveillance {{!}} CDC|url=https://www.cdc.gov/norovirus/reporting/index.html|website=www.cdc.gov|publisher=[[Centers for Disease Control and Prevention]]|access-date=26 November 2017|language=en-us|date=28 December 2016|archive-date=9 December 2017|archive-url=https://web.archive.org/web/20171209145710/https://www.cdc.gov/norovirus/reporting/index.html|url-status=live}}</ref>

===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]].<ref name="pmid16765204">{{cite journal |vauthors=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 }}</ref> [[Hand sanitizers]] based on [[Alcohol (chemistry)|alcohols]] tend to be ineffective against noroviruses due to their being [[Viral envelope|non-enveloped]], although some virus genotypes were found in ''[[in vitro]]'' tests with [[ethanol]] and [[isopropyl alcohol]] to be more susceptible. Alcohol susceptibility patterns between different norovirus genotypes were found to vary widely, and virolysis data for a single strain or genotype was not representative for all noroviruses.<ref name=park>{{cite journal | last1=Park | first1=Geun Woo | last2=Collins | first2=Nikail | last3=Barclay | first3=Leslie | last4=Hu | first4=Liya | last5=Prasad | first5=B. V. Venkataram | last6=Lopman | first6=Benjamin A. | last7=Vinjé | first7=Jan | title=Strain-Specific Virolysis Patterns of Human Noroviruses in Response to Alcohols | journal=PLOS ONE | volume=11 | issue=6 | date=23 June 2016 | issn=1932-6203 | pmid=27337036 | pmc=4919085 | doi=10.1371/journal.pone.0157787 | doi-access=free | page=e0157787}}</ref><ref>{{Cite web|date=2017-10-19|title=Norovirus (vomiting bug)|url=https://www.nhs.uk/conditions/norovirus/|access-date=2021-05-29|website=nhs.uk|language=en|archive-date=2018-06-12|archive-url=https://web.archive.org/web/20180612143424/https://www.nhs.uk/conditions/norovirus/|url-status=live}}</ref> Another study found that alcohol in combination with acid (1% [[citric acid]], e.g. from 15% concentrated lemon juice) produced an effective disinfectant of noroviruses.<ref>{{cite journal | last=Sato | first=Shintaro | last2=Matsumoto | first2=Naomi | last3=Hisaie | first3=Kota | last4=Uematsu | first4=Satoshi | title=Alcohol abrogates human norovirus infectivity in a pH-dependent manner | journal=Scientific Reports| volume=10 | issue=1 | date=28 September 2020 | issn=2045-2322 | doi=10.1038/s41598-020-72609-z | doi-access=free | url=https://www.nature.com/articles/s41598-020-72609-z.pdf}}</ref>

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.<ref name="cdcfactsheet"/><ref>{{cite web|url=https://www.epa.gov/pesticide-registration/list-g-epa-registered-hospital-disinfectants-effective-against-norovirus|title=List G: EPA Registered Hospital Disinfectants Effective Against Norovirus (Norwalk-like virus)|publisher=US Environmental Protection Agency|access-date=9 May 2016|date=2015-09-28|archive-date=2016-04-15|archive-url=https://web.archive.org/web/20160415170327/https://www.epa.gov/pesticide-registration/list-g-epa-registered-hospital-disinfectants-effective-against-norovirus|url-status=live}}</ref><ref>{{cite web |url=http://www.thenakedscientists.com/HTML/content/interviews/interview/838/ |title=Gastroenteritis and Noroviruses—Dr Jim Grey, Health Protection Agency |publisher=The Naked Scientists |date=2007-12-09 |access-date=2014-02-09 |archive-date=2014-03-31 |archive-url=https://web.archive.org/web/20140331051859/http://www.thenakedscientists.com/HTML/content/interviews/interview/838/ |url-status=live }}</ref>

===Health care facilities===
In healthcare environments, the prevention of [[nosocomial infection]]s involves routine and [[terminal cleaning]]. [[Nonflammable alcohol vapor in CO2 systems|Nonflammable alcohol vapor in CO<sub>2</sub> systems]] is used in health care environments where medical electronics would be adversely affected by aerosolized chlorine or other caustic compounds.<ref name="pmid10833336">{{cite journal |vauthors=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 gastroenteritis due to small round structured viruses | journal = J. Hosp. Infect. | volume = 45 | issue = 1 | pages = 1–10 | year = 2000 | pmid = 10833336 | doi = 10.1053/jhin.2000.0662 }}</ref>

In 2011, the CDC published a clinical practice guideline addressing strategies for the prevention and control of norovirus gastroenteritis outbreaks in healthcare settings.<ref>{{cite web|last1=HICPAC|title=Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in Healthcare Settings, 2011|url=https://www.cdc.gov/hicpac/norovirus/002_norovirus-toc.html|website=Healthcare Infection Control Practices Advisory Committee (HICPAC)|publisher=Centers for Disease Control and Prevention (CDC)|access-date=19 March 2015|archive-date=27 March 2015|archive-url=https://web.archive.org/web/20150327010357/http://www.cdc.gov/hicpac/norovirus/002_norovirus-toc.html|url-status=live}}</ref><ref>{{cite journal | vauthors = MacCannell T, Umscheid CA, Agarwal RK, Lee I, Kuntz G, Stevenson KB | title = Guideline for the prevention and control of norovirus gastroenteritis outbreaks in healthcare settings | journal = Infection Control and Hospital Epidemiology | volume = 32 | issue = 10 | pages = 939–69 | date = October 2011 | pmid = 21931246 | doi = 10.1086/662025 | s2cid = 27996748 }}</ref> Based on a systematic review of published scientific studies, the guideline presents 51 specific [[Evidence-based medicine|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.{{cn|date=August 2022}}

===Vaccine trials===
LigoCyte announced in 2007 that it was working on a vaccine and had started phase 1 trials.<ref name="Norovac">{{cite web| title=Norovirus Vaccine| url=http://www.ligocyte.com/downloads/Noro.pdf| access-date=2008-08-26| archive-date=2008-10-02| archive-url=https://web.archive.org/web/20081002175650/http://www.ligocyte.com/downloads/Noro.pdf| url-status=live}}</ref> The company has since been taken over by [[Takeda Pharmaceutical Company]].<ref>{{cite web| title=Takeda to Acquire LigoCyte Pharmaceuticals, Inc.| url=http://www.takeda.com/news/2012/20121005_4001.html| access-date=2013-06-22| archive-date=2013-06-29| archive-url=https://web.archive.org/web/20130629235039/http://www.takeda.com/news/2012/20121005_4001.html| url-status=live}}</ref> {{As of|2019||df=}}, a bivalent (NoV GI.1/GII.4) intramuscular vaccine had completed phase 1 trials.<ref>{{Cite journal|last1=Baehner|first1=F.|last2=Bogaerts|first2=H.|last3=Goodwin|first3=R.|date=2016-12-01|title=Vaccines against norovirus: state of the art trials in children and adults|journal=Clinical Microbiology and Infection|series=Vaccines for Mutual Protection: Selected Proceedings from the 3rd ESCMID Conference on Vaccines|volume=22|pages=S136–S139|doi=10.1016/j.cmi.2015.12.023|pmid=27130672|issn=1198-743X|doi-access=free}}</ref><ref>{{Cite web|url=https://www.takeda.com/siteassets/system/what-we-do/research-and-development-rd-in-takeda/our-pipeline/pipeline_en_2019_q2.pdf|title=Key Products and Pipeline (FY2019 Q2 Pipeline Table)|date=2019|website=[[Takeda Pharmaceutical Company]]|access-date=9 December 2019|archive-date=6 November 2019|archive-url=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|url-status=live}}</ref> In 2020 the phase 2b trials were finished.<ref>{{cite web |title=HilleVax Pipeline |url=https://www.hillevax.com/pipeline.html |website=Hillevax Pipeline |access-date=1 October 2021 |archive-date=1 October 2021 |archive-url=https://web.archive.org/web/20211001201039/https://www.hillevax.com/pipeline.html |url-status=live }}</ref><ref>{{cite journal |last1=Sherwood |first1=J |last2=Mendelman |first2=PM |last3=Lloyd |first3=E |last4=Liu |first4=M |last5=Boslego |first5=J |last6=Borkowski |first6=A |last7=Jackson |first7=A |last8=Faix |first8=D |last9=US Navy study |first9=team. |title=Efficacy of an intramuscular bivalent norovirus GI.1/GII.4 virus-like particle vaccine candidate in healthy US adults. |journal=Vaccine |date=22 September 2020 |volume=38 |issue=41 |pages=6442–6449 |doi=10.1016/j.vaccine.2020.07.069 |pmid=32878708 |doi-access=free }}</ref> 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.<ref name="Norovac"/>

=== 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,<ref>{{cite web |url=http://www.webmd.com/cold-and-flu/features/how-to-stay-well-when-everyone-else-is-sick |title=How To Stay Well (When Everyone Else Is Sick) |publisher=Webmd.com |access-date=2017-01-28 |url-status=dead |archive-url=https://web.archive.org/web/20140103204322/http://www.webmd.com/cold-and-flu/features/how-to-stay-well-when-everyone-else-is-sick |archive-date=2014-01-03 }}</ref> and it can survive for months, maybe even years in contaminated still water.<ref>{{cite web| url=http://blogs.scientificamerican.com/artful-amoeba/2012/01/17/misery-inducing-norovirus-can-survive-for-months-perhaps-years-in-drinking-water/| title=Misery-inducing Norovirus Can Survive for Months—Perhaps Years—in Drinking Water| vauthors=Frazer J| date=January 17, 2012| website=Scientific American| access-date=February 27, 2012| archive-date=March 7, 2012| archive-url=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/| url-status=live}}</ref> A 2006 study found the virus remained on surfaces used for food preparation seven days after contamination.<ref>{{cite journal |vauthors=D'Souza DH, Sair A, Williams K, Papafragkou E, Jean J, Moore C, Jaykus L | title = Persistence of caliciviruses on environmental surfaces and their transfer to food | journal = International Journal of Food Microbiology | volume = 108 | issue = 1 | pages = 84–91 | year = 2006 | pmid = 16473426 | doi = 10.1016/j.ijfoodmicro.2005.10.024 }}</ref>

=== 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.<ref name="pmid10804149">{{cite journal |vauthors=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 | issue = Suppl 2 | pages = S360–6 | year = 2000 | pmid = 10804149 | doi = 10.1086/315578 | doi-access = free }}</ref>