Editing Anisakis (section)

==Health implications==
{{Split section|Anisakiasis |discuss={{TALKPAGENAME}}#Split proposed |date=January 2024}}
Anisakids pose a risk to human health through intestinal infection with worms from the eating of underprocessed fish and through allergic reactions to chemicals left by the worms in fish flesh.<ref name="pmid17823758">{{cite journal |vauthors=Amato Neto V, Amato JG, Amato VS |title=Probable recognition of human anisakiasis in Brazil |journal=Rev. Inst. Med. Trop. Sao Paulo |volume=49 |issue=4 |pages=261–62 |year=2007 |pmid=17823758 |doi= 10.1590/s0036-46652007000400013|doi-access=free}}</ref>

===Anisakiasis===
{{Infobox medical condition (new)
| name            = Anisakiasis
| synonyms        =
| image           = Symptoms of Raw fish infection.png
| caption         = Differential symptoms of parasite infection by raw fish: ''[[Clonorchis sinensis]]'' (trematode/fluke), ''Anisakis'' (nematode/roundworm) and ''[[Diphyllobothrium]]'' (cestode/tapeworm),<ref name=wai>[http://www.13.waisays.com/fish.htm WaiSays: "About Consuming Raw Fish"] Retrieved on April 14, 2009</ref> all have gastrointestinal, but otherwise distinct, symptoms.<ref>For Chlonorchiasis: [http://www.phac-aspc.gc.ca/msds-ftss/msds34e-eng.php Public Health Agency of Canada > Clonorchis sinensis – Material Safety Data Sheets (MSDS)] Retrieved on April 14, 2009</ref><ref>For Anisakiasis: [http://www.wrongdiagnosis.com/a/anisakiasis/symptoms.htm WrongDiagnosis: "Symptoms of Anisakiasis"] Retrieved on April 14, 2009</ref><ref>For Diphyllobothrium: [https://www.nlm.nih.gov/medlineplus/ency/article/001375.htm#Symptoms MedlinePlus > "Diphyllobothriasis"] Updated by: Arnold L. Lentnek, MD. Retrieved on April 14, 2009</ref><ref>For symptoms of diphyllobothrium due to vitamin B<sub>12</sub>-deficiency [http://www.umm.edu/blood/aneper.htm University of Maryland Medical Center > "Megaloblastic (Pernicious) Anemia"] {{Webarchive|url=https://web.archive.org/web/20111126022240/http://www.umm.edu/blood/aneper.htm |date=2011-11-26 }} Retrieved on April 14, 2009</ref>
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| field           = [[Infectious disease (medical speciality)|Infectious disease]]
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Anisakiasis is a human parasitic infection of the gastrointestinal tract caused by the consumption of raw or undercooked seafood containing larvae of the [[nematode]] ''Anisakis simplex''.

Within a few hours of ingestion, the parasitic worm tries to burrow through the intestinal wall, but since it cannot penetrate it, it gets stuck and dies. The presence of the parasite triggers an immune response; immune cells surround the worms, forming a ball-like structure that can block the [[digestive system]], causing severe abdominal pain, malnutrition, and vomiting. Occasionally, the larvae are regurgitated.  If the larvae pass into the bowel or large intestine, a severe [[eosinophilic]] [[granulomatous]] response may also occur one to two weeks following infection, causing symptoms mimicking [[Crohn's disease]].<ref>{{cite journal |last1=Montalto |first1=M. |last2=Miele |first2=L. |last3=Marcheggiano |first3=A. |last4=Santoro |first4=L. |last5=Curigliano |first5=V. |last6=Vastola |first6=M. |last7=Gasbarrini |first7=G. |title=Anisakis infestation: a case of acute abdomen mimicking Crohn's disease and eosinophilic gastroenteritis |journal=Digestive and Liver Disease |date=January 2005 |volume=37 |issue=1 |pages=62–64 |doi=10.1016/j.dld.2004.05.014 |pmid=15702862 }}</ref><ref>{{Cite web |date=2019-05-16 |title=CDC - DPDx - Anisakiasis |url=https://www.cdc.gov/dpdx/anisakiasis/index.html |access-date=2023-02-17 |website=www.cdc.gov |language=en-us}}</ref> Anisakiasis may present as a gastric, intestinal, or allergic disease.<ref name="Biomedica2019">{{cite journal |last1=Patiño |first1=JA |last2=Olivera |first2=MJ |title=Gastro-allergic anisakiasis: The first case reported in Colombia and a literature review. |journal=Biomedica: Revista del Instituto Nacional de Salud |date=15 June 2019 |volume=39 |issue=2 |pages=241–246 |doi=10.7705/biomedica.v39i2.3936 |pmid=31529811|doi-access=free }}</ref>

The first case of human infection by a member of the family Anisakidae was reported in the Netherlands by Van Thiel, who described the presence of a marine nematode in a patient suffering from acute abdominal pain.<ref name="Audicana">{{cite journal |last1=Audicana |first1=Maria Teresa |last2=Kennedy |first2=MW |year=2008 |title=Anisakis Simplex: From Obscure Infectious Worm to Inducer of Immune Hypersensitivity |journal=Clinical Microbiology Reviews |volume=21 |issue=2 |pages=360–79 |doi=10.1128/CMR.00012-07 |pmc=2292572 |pmid=18400801}}</ref> It is frequently reported in areas of the world where fish is consumed raw, lightly pickled, or salted.  The areas of highest prevalence are Scandinavia (from [[cod]] [[livers]]), Japan (after eating [[sashimi]]), the Netherlands (by eating infected [[Soused herring|fermented herrings]] (''maatjes''), Spain (from eating anchovies and other fish marinated in ''[[escabeche]]''), and along the Pacific coast of South America (from eating ''[[ceviche]]''). The frequency in the United States is unknown because the disease is not reportable{{Citation needed|date=September 2021}} and can go undetected or be mistaken for other illnesses. Anisakiasis was first recognized in the 1960s.
During the 1970s, about 10 cases per year were reported in the literature. The frequency is probably much higher, due to home preparation of raw or undercooked fish dishes. In Japan, more than 1,000 cases are reported annually.<ref name="FDA">[https://web.archive.org/web/20130418013247/http://www.fda.gov/downloads/Food/FoodborneIllnessContaminants/UCM297627.pdf ''Bad Bug Book: Foodborne Pathogens Microorganisms and Natural Toxins Handbook''], 2nd edition Food and Drug Administration.</ref> Development of better diagnostic tools and greater awareness has led to more frequent reporting of anisakiasis.

==== Diagnosis ====
Diagnosis can be made by gastroscopic examination, during which the 2-cm larvae are visually observed and removed, or by histopathologic examination of tissue removed at biopsy or during surgery.{{citation needed|date=January 2023}}

Important clues for the diagnosis of anisakiasis include a recent history of eating raw or insufficiently cooked fish or squid followed by the sudden start of epigastric or right lower quadrant stomach pain. The removal and examination of the larva by gastroscopy or surgery provides a definitive diagnosis.<ref>{{Cite journal |last1=Hochberg |first1=Natasha S. |last2=Hamer |first2=Davidson H. |date=2010-10-01 |title=Anisakidosis: Perils of the deep |journal=Clinical Infectious Diseases |volume=51 |issue=7 |pages=806–812 |doi=10.1086/656238 |issn=1537-6591 |pmid=20804423 |doi-access=free}}</ref>

==== Prevention ====
Raising consumer and producer awareness about the existence of anisakid worms in fish is a critical and effective prevention strategy. Anisakiasis can be easily prevented by adequate cooking at temperatures greater than 60&nbsp;°C{{Citation needed|date=November 2021}} or freezing. The FDA recommends all shellfish and fish intended for raw consumption be blast frozen to −35&nbsp;°C or below for 15 hours or be regularly frozen to −20&nbsp;°C or below for seven days.<ref name="FDA" /> Salting and marinating will not necessarily kill the parasites, as in Italy where two-thirds of cases were attributed to [[European anchovy|anchovies]] marinated in lemon or vinegar.<ref name="GuardoneArmani2018">{{cite journal |last1=Guardone |first1=Lisa |last2=Armani |first2=Andrea |last3=Nucera |first3=Daniele |last4=Costanzo |first4=Francesco |last5=Mattiucci |first5=Simonetta |last6=Bruschi |first6=Fabrizio |date=30 July 2018 |title=Human anisakiasis in Italy: a retrospective epidemiological study over two decades |journal=Parasite |volume=25 |pages=41 |doi=10.1051/parasite/2018034 |pmc=6065268 |pmid=30058531}}</ref> Humans are thought to be more at risk of anisakiasis from eating wild fish rather than farmed fish. {{Citation needed|date=June 2022}} Many countries require all types of fish with potential risk intended for raw consumption to be previously frozen to kill parasites. The mandate to freeze herring in the Netherlands has virtually eliminated human anisakiasis in the Netherlands.<ref name="John">{{cite book |last=John |first=David T. |url=https://archive.org/details/markellvogesmedi0000mark_8thed/page/267 |title=Markell and Voge's Medical Parasitology |author2=William Petri |publisher=Saunders |year=2006 |isbn=978-0-7216-7634-0 |location=St. Louis |pages=[https://archive.org/details/markellvogesmedi0000mark_8thed/page/267 267–70]}}</ref>

The best preventive measure for Anisiakis is to avoid eating raw or undercooked fish or squid.<ref>{{Cite web |date=2020-09-16 |title =Anisakiasis FAQs |url= https://www.cdc.gov/parasites/anisakiasis/faqs.html |access-date= |website=www.cdc.gov |language=en-us}}</ref> Another common prevention method is the thermal treatment of the fish or squid prior to consumption. The fish or squid should be cooked at >60&nbsp;°C for >1 min or frozen whole at −20&nbsp;°C for >24 h.<ref>{{Cite journal |last1=Adroher-Auroux |first1=Francisco Javier |last2=Benítez-Rodríguez |first2=Rocío |date=2020-10-01 |title=Anisakiasis and Anisakis: An underdiagnosed emerging disease and its main etiological agents |url=https://www.sciencedirect.com/science/article/pii/S0034528820309759 |journal=Research in Veterinary Science |language=en |volume=132 |pages=535–545 |doi=10.1016/j.rvsc.2020.08.003 |issn=0034-5288 |pmid=32828066 |s2cid=221258565|hdl=10481/89372 |hdl-access=free }}</ref>

==== Treatment ====
For the worm, humans are a dead-end host. ''Anisakis'' and ''Pseudoterranova'' larvae cannot survive in humans, and eventually die. In some cases, the infection resolves with only symptomatic treatment.<ref name="pmid19336962">{{cite journal |last1=Nakaji |first1=Konosuke |date=2009 |title=Enteric Anisakiasis Which Improved with Conservative Treatment |journal=Internal Medicine |volume=48 |issue=7 |pages=573 |doi=10.2169/internalmedicine.48.1905 |pmid=19336962 |doi-access=free}}</ref> In other cases, however, the infection can lead to [[small bowel obstruction]], which may require surgery,<ref name="pmid18427347">{{cite journal |last1=Sugita |first1=Satoshi |last2=Sasaki |first2=Atsushi |last3=Shiraishi |first3=Norio |last4=Kitano |first4=Seigo |date=April 2008 |title=Laparoscopic Treatment for a Case of Ileal Anisakiasis |journal=Surgical Laparoscopy, Endoscopy & Percutaneous Techniques |volume=18 |issue=2 |pages=216–218 |doi=10.1097/SLE.0b013e318166145c |pmid=18427347}}</ref> although treatment with [[albendazole]] alone (avoiding surgery) has been reported to be successful. [[Intestinal perforation]] (an emergency) is a possible complication.<ref>{{cite journal |last1=Pacios |first1=Enrique |last2=Arias-Diaz |first2=Javier |last3=Zuloaga |first3=Jaime |last4=Gonzalez-Armengol |first4=Juan |last5=Villarroel |first5=Pedro |last6=Balibrea |first6=Jose L. |date=December 2005 |title=Albendazole for the Treatment of Anisakiasis Ileus |journal=Clinical Infectious Diseases |volume=41 |issue=12 |pages=1825–1826 |doi=10.1086/498309 |pmid=16288416 |doi-access=free}}</ref>

===Allergic reactions===
Even when the fish is thoroughly cooked, ''Anisakis'' larvae pose a health risk to humans. Anisakids (and related species such as the sealworm, ''Pseudoterranova'' species, and the codworm ''Hysterothylacium aduncum'') release many [[biochemical]]s into the surrounding tissues when they infect a fish. They are also often consumed whole, accidentally, inside a fillet of fish.{{citation needed|date=January 2023}}

[[File:Anisakids.jpg|thumb|right|Anisakid larvae in the body cavity of a [[herring]] (''Clupea harengus'')]]

Acute allergic manifestations, such as [[urticaria]] and [[anaphylaxis]], may occur with or without accompanying gastrointestinal symptoms. The frequency of allergic symptoms in connection with fish ingestion has led to the concept of gastroallergic anisakiasis, an acute IgE-mediated generalized reaction.<ref name=Audicana/> Occupational allergy, including asthma, conjunctivitis, and contact dermatitis, has been observed in fish processing workers.<ref name=Nieuwenhuizen>{{cite journal  | last1 = Nieuwenhuizen  | first1 = N  | title = Exposure to the Fish Parasite Anisakis Causes Allergic Airway Hyperreactivity and Dermatitis  | journal = The Journal of Allergy and Clinical Immunology  | volume = 117  | issue = 5  | year = 2003  | pages = 1098–105  | pmid = 16675338  | last2 = Lopata  | first2 = AL  | last3 = Jeebhay  | first3 = MF  | last4 = Herbert  | first4 = DR  | last5 = Robins  | first5 = TG  | last6 = Brombacher  | first6 = F  | doi = 10.1016/j.jaci.2005.12.1357| doi-access = free  }}</ref>
sensitization and allergy is determined by skin-prick test and detection of specific antibodies against ''Anisakis''. Hypersensitivity is indicated by a rapid rise in levels of [[immunoglobulin E|IgE]] in the first several days following consumption of infected fish.<ref name=Audicana/> A 2018 review of cases in France has shown that allergic cases were more commonly found, although the number of human ''Anisakis'' infections was decreasing.<ref name="YeraFréalle2018">{{cite journal |last1=Yera |first1=Hélène |last2=Fréalle |first2=Émilie |last3=Dutoit |first3=Emmanuel |last4=Dupouy-Camet |first4=Jean |title=A national retrospective survey of anisakidosis in France (2010-2014): decreasing incidence, female predominance, and emerging allergic potential |journal=Parasite |date=11 April 2018 |volume=25 |pages=23 |doi=10.1051/parasite/2018016 |pmid=29637891 |pmc=5894341}}</ref>