11/25/2013

Anisakis

Anisakis is a parasite which could be found in raw seafood like squid or salmon. I thought its infection or infestation had been a rare event. But, when talking about it with my wife a few days ago, I have heard from her that a lady who used to prepare our dinner told her that she had found that parasite from time to time in raw squid.

This story may mean the case of anisakis infestation is not a rare problem but it could occur around myself. Anisakis could be killed by freezing the food. Chewing when eating certain food is also helpful to kill it. The gastric acid might be also a barrier to have Anisakis reach the gastric wall. But some could reach the gastric wall and infest it causing very bad stomachache. In the case of stomachache by Anisakis, you should undergo an endoscopic procedure and take it away from the stomache.

It is quite problematic that fresh raw seafood could cause this problem more easily. I have had raw seafood for thousands of times without any stomachache. There could be some genetic vulnerability for this infestation. I should study about that. But no one could assure I won't have the problem tomorrow.  So Dennis' comment on the risk of parasite infection is not negligible. And Don's belief Kirin would pasteurize the parasite doesn't seem practical either.

PS:After uploading this article, I found this review abstract. It won't mention about the genetic diversity in host defence against this parasite. There seem to be two pathophysiological causing problems in human being. One is the direct infestation. The other is an anaphylaxis via specific IgE. The immunogenetic factor must be involved in the latter. The severer allergological symptoms should occur only in selected cases determined by the immunogenetic trait.


2012 Aug;44(4):150-6.

Anisakis simplex: current knowledge.

Source

Clinical Allergy and Immunology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Pace, 9, 20122 Milan, Italy. v.pravettoni@policinico.mi.it

Abstract

Anisakiasis, firstly described in 1960s in the Netherlands, is a fish-borne parasitic disease caused by the consumption of raw or undercooked fish or cephalopods contaminated by third stage (13) larvae of the Anisakidae family, in particular Anisakis simplex (As), A. pegreffii and Pseudoterranova decipiens. Every year, approximately 20,000 cases of anisakiasis were reported worldwide, over 90% are from Japan and most others in Spain, the Netherlands and Germany, depending on the habits of fish consuming. Live As larvae can elicit i) a parasitic infection of the digestive tract or, occasionally, other organs, causing erosive and/or haemorrhagic lesions, ascites, perforations until granulomas and masses, if larva is not removed, and ii) allergic reactions, as anaphylaxis, acute/chronic urticaria and angioedema. Like other parasite infestations, As larva induces an immune adaptive response characterised by T-lymphocyte proliferation with polyclonal and monoclonal (responsible for As allergic symptoms) IgE production, eosinophilia and mastocytosis. Several As allergens, many of which thermostable, were described In particular the major allergen Ani s 1 and Ani s 7 could characterized a past or a recent infection. There is a general agreement that an active infection is required to initiate allergic sensitivity to Anisakis. Until now, the only effective treatment for anisakiasis is the endoscopic removal of live larvae and the best protection against anisakiasis is to educate consumers about the dangers of eating raw fish and to recommend avoiding the consumption of raw or inadequately thermally treated marine fish or cephalopods. 

3 comments:

  1. Shin
    Science has a way of determining that virtually anything we do as living organisms has risk. Maybe it's a good thing that science has accomplished so many good insights into the risk of living. But, science cannot remove the joys of certain things. People jump out of airplanes or dive to depths in the ocean. All are risks that science would say are above average, perhaps insurmountable. If you really look at statistics, one probably would never drive a car, or ride with someone under the age of 21. The fact remains that the overbearing presence of human life on this planet changes nature's equation for equilibrium between life and death. As you have so noted, such things as atomic energy, chemical food preservatives and herbicides/pesticides in our food chain will do nothing but reduce the cost of food and increase the risk of life. For me, I must say, I fully intend to enjoy what remains of my short period on this earth and will take some level of risk to do so. By the way, you misquoted me. I said TWO Kirin beers would cure the risk....

    Thank you for a nice visit this evening, Shin

    Don

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    Replies
    1. We could live without eating raw fish, Don. The problem is if we would go on eating them with the knowledge of the probability for the risk. 20.000 cases a year in the world. You enjoy fresh squid. So do I! Maybe, I would choose frozen one, though. I can't have such amount of beer at the same time.

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  2. Shin, your cautions are well noted and appropriate. 20,000 cases per year is an astronomical number. We kill about 30,000 people per year in car accidents, but that is only 10.38 per every 100 million in population. That is down from twice that in the early 80's. At Korean Sushi place, they had Sake bombers. Warm Sake in shot glass with large bottle of Kirin. Maybe that's the vaccination.

    I am just joking with you.

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