Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!brl-adm!rutgers!ll-xn!adelie!axiom!linus!philabs!aecom!werner From: werner@aecom.UUCP (Craig Werner) Newsgroups: sci.med,net.cooks Subject: Sushi and Parasites Message-ID: <576@aecom.UUCP> Date: Tue, 4-Nov-86 00:56:49 EST Article-I.D.: aecom.576 Posted: Tue Nov 4 00:56:49 1986 Date-Received: Wed, 5-Nov-86 22:25:06 EST Distribution: na Organization: Albert Einstein Coll. of Med., NY Lines: 70 Xref: mnetor sci.med:177 net.cooks:4105 <<>> As both a parasitologist and a sushi chef, I often get questions from people who worry about the little nasties that might be lurking it the raw fish that they are about to eat. What follows is a summary : By and large, as long as one limits oneself to salt water fish, one need not worry about parasites. One should not eat fresh water fish raw. Avoid the temptation to make sushi from fish that you have caught yourself, as parasites as probably the least of your worries. Salmon is used for Sushi, but only after smoking, not raw. The ingestion of raw salmon is associated with cases of the parasite Diphyllobothria, the fish tapeworm. Undercooked cod has been associated with phocanemea, as has filet of haddock. (Phocanema is a roundworm). The most common parasitic infection is Anisakis, another roundworm, and it is generally associated with eating raw mackerel. In both Phocanema and Anisakis, the parasite is unable to colonize the human host, and after a few days of acute gastroenteritis, the parasite is either coughed up or passed. It can also be removed endoscopically by a doctor in a matter of minutes. Finally, I should point out a much more common reason for illness after eating raw food is bacteria. Particular among those bacteria that live in salt water is Vibrio parahemolyticus (a cousin of Vibrio cholera) but more mundane bacteria are usually involved. I should note that the number of reported cases of parasite infection secondary to ingestion of sushi numbers only 10-20 cases per year, if that many. References and a repost of an article from last year: Chitwood, M. Nematodes of Medical Significance Found in Market Fish Am J Trop Med Hyg 1970;19:599-602. Chitwood M. Phocanema-type larval nematode coughed up by a boy in California. Am J Trop Med Hyg 1975;24:710-711. Ishizuka T, Ishizuka A, A case of Diphyllobothriasis due to eating masou- sushi [letter]. Med J Australia 1986;145:114. Goldmann, DR. Hold the Sushi! [letter] JAMA 1985;253:2495-6. The article: Sushi found to harbor Parasites. (fr. American Medical News) Kwizo Sugimachi, MD and colleagues at Kyushu U. cite 178 cases of Anisakis larval infection resulting from uncooked fish in the 15 years between 1969 and 1984. Raw Mackerel accounted for 87% of the cases. All patients became ill within 12 hours after eating the fish. All were treated successfully by endoscopically removing the larvae and administering antacids. Otherwise the pain would have persisted for several days until the larvae died. Most of the US cases are a Phocanema-like larvae that is usually coughed up. Most larvae, however, pass through the systen without causing any distress. Larvae in fish can be killed by smoking or cooking, and also by freezing at -20C for three days (so much for fresh fish). Oh, and one last thing: for those in the greater New York area, my next sushi party will be Sat. Nov. 15, 9:00 pm, at my apartment. RSVP. -- Craig Werner (MD/PhD '91) !philabs!aecom!werner (1935-14E Eastchester Rd., Bronx NY 10461, 212-931-2517) "Knowing you, you're probably doing twice as much as is healthy for you."