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Published Date: 2012-03-31 11:08:08
Subject: PRO/EDR> Botulism - USA: (NYC), tofu susp., alert
Archive Number: 20120331.1086556
BOTULISM - USA: (NEW YORK CITY), TOFU SUSPECTED, ALERT
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A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Sat 31 Mar 2012
Source: New York Daily News [edited]
2 people developed botulism, a rare but potentially fatal foodborne illness, after buying tofu at a store in Flushing. The NYC Health Department said in a release Friday evening, 30 Mar 2012, that it confirmed 1 case and suspected another case.
Both of the afflicted are Chinese-speaking Queens residents who recently bought fresh, unrefrigerated bulk tofu from a Flushing market. The tofu was not made at the store, and its source is under investigation, the Health Department release states.
"This kind of tofu, commonly sold in an open, water-filled bin, is highly suspected to be the source of these cases; however it has not yet been confirmed," the release states. Fresh, unrefrigerated tofu is used to make fermented tofu and is an ingredient in a popular Chinese dish called chou doufu, or stinky tofu. Anyone who has bought this variety of tofu is urged to throw it away, even if they cooked it, because the spores can survive cooking.
A Health Department spokewoman said neither patient has died of the illness, but declined to comment on their condition. She also declined to name the Flushing store where the two bought the tofu. "We're still investigating the origin and destinations of the tofu, and because of that we aren't disclosing the name of the store," she said.
New York City has seen only 1 other case of foodborne botulism in the past 15 years.
[Byline: Kerry Wills]
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[The English word "tofu" (http://en.wikipedia.org/wiki/Tofu) comes from the Japanese, which itself derives from the Chinese doufu from "bean" plus "curdled" or "fermented". Tofu is made by coagulating soy milk and pressing the resulting curds. Although pre-made soy milk may be used, most tofu producers begin by making their own soy milk, which is produced by soaking, grinding, boiling and straining dried (or, less commonly, fresh) soybeans. Coagulation of the protein and oil (emulsion) suspended in the boiled soy milk is the most important step in the production of tofu. This process is accomplished with the aid of coagulants. Two types of coagulants (salts and acids) are used commercially. Stinky tofu is a soft tofu that has been fermented in a unique vegetable and fish brine. The blocks of tofu smell strongly of certain pungent cheeses, and are described by many as rotten and fecal. Despite its strong odor, the flavor and texture of stinky tofu is appreciated by aficionados, who describe it as delightful. The texture of this tofu is similar to the soft Asian tofu that it is made from. The rind that stinky tofu develops from frying is said to be especially crisp, and is usually served with soy sauce, sweet sauce, and/or hot sauce.
Most USA botulism postings relate to the alert that a particular commercially prepared food was not adequately made which would increase a risk of intoxication with _C. botulinum toxin_. In most of these, no clear evidence of botulism is found in the food product. When botulism does occur related to food, it is most likely to be home-prepared. It should be noted that in typical food-borne botulism, the toxin is preformed in the food when ingested rather than disease being produced with ingestion of spores. Infant botulism (and its very rare adult equivalent, adult intestinal toxemia botulism) are caused by ingestion of spores, which germinate, and toxin is formed _in situ_.
Botulinum, the most toxic of known toxins, is produced by the gram-positive spore forming anaerobic bacterium _Clostridium botulinum_, found in soil worldwide. Botulism is caused by the consumption of contaminated products containing spores. Spores produce toxin when they germinate in the product or in the digestive tract. Humans are most often intoxicated by consumption of the preformed toxin in such things as home-canned vegetables or even baked potatoes left unrefrigerated. As little as 0.001 microgram per kilogram body weight may be lethal. The time from ingestion of the toxin until clinical signs are observed will vary with the amount of toxin ingested. The onset of clinical signs may be as short as a few hours but is seldom more than 24 hours. A very small amount of material containing the toxin can cause symptoms. Signs can develop rapidly and death can occur in a little as 6 hours after initial onset. Clinical signs may begin in human beings between 12-36 hours after ingestion of the toxin. The clinical signs and symptoms in human beings include ptosis, blurred vision, diplopia [double vision], dry mouth & throat, dysphagia, and dysphoria. These are a result of cranial nerve palsies. These early signs are followed by symmetrical descending flaccid paralysis, with generalized weakness and progression to respiratory failure. -Mod. LL]
[For a map of NYC showing the 5 boroughs, see http://www.nycgo.com/maps. Flushing is located in Queens, and a description of the neighborhood can be found at http://www.nycgo.com/slideshows/must-see-flushing. The HealthMap/ProMED map of New York City can be found at: http://healthmap.org/r/1FWY. - Mod.MPP]