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Subject: Rec.Food.Preserving FAQ (v.7.08) Part5

This article was archived around: Sat, 24 Aug 2002 22:14:42 -0400

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Archive-name: food/preserving/part5 Posting-Frequency: monthly (on or about 20th) Last-modified: 2002/08/02 Version: 7.08 Copyright: (c) 1998-2002 Eric Decker ( and others as specified within ) Maintainer: Eric Decker <ericnospam@getcomputing.com>
Rec.Food.Preserving FAQ FREQUENTLY ASKED QUESTIONS (FAQ) in the newsgroup preserving This FAQ and all its constituent parts, as a collection of information, is Copyright 1998-2002 by Eric Decker, as a work of literature. Distribution by any electronic means is granted with the understanding that the article not be altered in any way. Permission to distribute in printed form must be obtained in writing. The removal of this copyright notice is forbidden. ---------------------------------------------------------------------------- Disclaimer: No author represented in this FAQ is qualified to establish scheduled processes nor is any author a competent processing authority in the sense of 21 CFR 113.83 et alia. ----------------------------------------------------------------------------- Part 5 of 6 13. Spoilage, Especially Botulism 13.1 [Okay, I've got some bad jars. What's growing in them? How can I dispose of them?] ---- HOME CANNED FOOD SPOILAGE--WHAT WENT WRONG?? 0.1 Jars and lids that are not sterile. Food placed in unsterilized jars or even air contact with non-sterile lids provide a bacteria source that can ramp up in numbers VERY rapidly. Processing times are deemed for uncontaminated food and vessels. ----------------- 1. Fresh food was decayed, unwashed, unpeeled or untrimmed. This results in a high microbial load. A larger than normal number of microorganisms can take a longer processing time for complete sterilization than is usually recommended. 2. Food packed too tightly in jars. Temperature in the geometric center of the jar was not high enough long enough to result in complete sterilization of the food. Pack food loosely, prepare according to USDA Guidelines (1/2 inch slices, halves, etc.) then use the recommended time, pressure, temperature. 3. Jars became un-sterile soon after being filled. If lids are not placed on jars and processing is not started immediately after jars are filled, microorganisms may start to grow and reach very high levels prior to processing. 4. Inaccurate heat-processing time was used; this may occur if old recommendations are used (food is underprocessed) or if the timing was interrupted (power failure, pressure fluctuation, etc.) 5. Food was not processed at the correct temperature: A. Pressure Canner (240F, 115C). 1. Failed to test dial gauge yearly. 2. Failed to exhaust canner 10 min with full steam flow. 3. Failed to make an adjustment for elevation (11 PSIG versus 10 PSIG in Illinois due to average 1000 above sea level altitude) 4. Failed to keep pressure accurate (high enough). B. Boiling Water Bath Canner 1. Water was not covering jar tops by 2" or more. 2. Water was not maintained at a rolling boil. 3. Processing time was too short. 4. Failed to make an adjustment for altitude (addition of 2 minutes for every 1000 ft above sea level). 6. Use of Open Kettle Canning, Microwave Canning, or Oven Canning Methods. These methods do not get the canned food hot enough long enough to destroy microorganisms so the food may spoil, may contain dangerous microorganisms and their toxins, or both. 7. Improper cooling of jars after processing: A. Failure to remove jars from canner at the end of processing time or when gauge reads "0". As jars cool, they may suck water (containing microbes or spores) back into the food. B. Failure to properly cool jars. Very slow or very rapid cooling may interfere with formation of a seal. 8. Use of paraffin to seal jelly jars. Paraffin is no longer recommended for sealing jams, jellies or preserves. Mold, which is the most common spoiler of sweet spreads, can send "roots" down along the edge of the paraffin and produce toxic substances into the spread. 9. Improper storage of home-canned foods: A. Home canned foods which are exposed to temperatures in excess of 95F may spoil. Sterilization recommendations used for home canning do not necessarily kill some of the "thermophiles" or heat-loving microorganisms. These organisms tolerate high temperatures and will grow at high temperatures. If they are still present, they may grow and spoil the food, or alter the food so that other microorganisms can grow. B. Home canned foods which are stored in the sunlight may get very hot inside--the light goes in, changes to heat as it is absorbed by the food, allows the air in the headspace to expand breaking open the seal allowing microorganisms to come in. C. Keeping very acid foods (pickled or fermented products, some juices) for a long period of time may give the food acid time to eat away at and deteriorate the lid resulting in pinholes which allow microorganisms to get into the jar. Discard any home canned food with damaged or flaking metal on the lid. D. Lids on home canned foods stored in a damp place may rust through allowing microbes to get into the food. Prepared by Susan Brewer/Foods and Nutrition Specialist/Revised, 1992 EHE-669 ---- UNSEALED JARS AND SPOILED FOOD--WHAT TO DO Occasionally even the most careful home canner has jars which become unsealed during storage resulting in food spoilage. Exposure to high temperatures or water during storage may cause the seals to break open or the lids to rust through allowing microorganisms access to the food inside. Any time a jar of home-canned food looks suspicious, treat it as though it were spoiled. Low-acid home-canned foods such as vegetables, meat, poultry and seafood are a special problem because of their association with botulism, so spoiled in these food categories should be detoxified before they are disposed of. 1. Do not taste food from an unsealed jar or any food which appears to be spoiled. Presence of black discoloration, gas, swelling of the lid, unnatural odors, spurting liquid and mold growth (blue, white, black or green) indicate spoilage. 2. Spoiled, low-acid foods (including tomatoes) may have no evidence of spoilage, so if they are suspect: A. Swollen but still sealed jars can be put in the garbage (in a heavy bag) or buried. B. Unsealed jars should be detoxified. 3. Detoxification: A. Place containers and lids on their sides in a large pot (8 qt or more). B. Wash hands well. C. Cover containers with water to at least 2" over them. D. Put lid on pot and bring to a boil. E. Boil 30 minutes. F. Cool and discard (in trash bag or bury). G. Scrub all counters, containers, equipment (including the can opener), clothing and hands that may have had contact with the food. Throw away sponges, wash cloths, etc. used in the clean-up. ALTERNATE DETOXIFICATION METHODS: Cover jar and food with chlorine bleach. Let stand 24 hours. Dispose of as above. Cover jar and food with a strong lye solution and let stand 24 hours. Dispose of as above. NOTE: Do not mix chlorine bleach and lye (sodium hydroxide) together. [Pick a detox method and stick with it.--LEB]. Prepared by Susan Brewer/Foods and Nutrition Specialist/Revised, 1992 EHE-680 ---- 13.1.2 [Botulism. What is it?] The word from the FDA, courtesy of Henry Hilbreath, aka souris.. Food and Drug Administration Foodborne Pathogenic Microorganisms and Natural Toxins 1992 1. Name of the organism: Clostridium botulinum Clostridium botulinum is an anaerobic, Gram-positive, spore-forming rod that produces a potent neurotoxin. The spores are heat-resistant and can survive in foods that are incorrectly or minimally processed. Seven types (A, B, C, D, E, F and G) of botulism are recognized, based on the antigenic specificity of the toxin produced by each strain. Types A, B, E and F cause human botulism. Types C and D cause most cases of botulism in animals. Animals most commonly affected are wild fowl and poultry, cattle, horses and some species of fish. Although type G has been isolated from soil in Argentina, no outbreaks involving it have been recognized. Foodborne botulism (as distinct from wound botulism and infant botulism) is a severe type of food poisoning caused by the ingestion of foods containing the potent neurotoxin formed during growth of the organism. The toxin is heat labile and can be destroyed if heated at 80C for 10 minutes or longer. The incidence of the disease is low, but the disease is of considerable concern because of its high mortality rate if not treated immediately and properly. Most of the 10 to 30 outbreaks that are reported annually in the United States are associated with inadequately processed, home-canned foods, but occasionally commercially produced foods have been involved in outbreaks. Sausages, meat products, canned vegetables and seafood products have been the most frequent vehicles for human botulism. The organism and its spores are widely distributed in nature. They occur in both cultivated and forest soils, bottom sediments of streams, lakes, and coastal waters, and in the intestinal tracts of fish and mammals, and in the gills and viscera of crabs and other shellfish. 2. Name of the Disease: Four types of botulism are recognized: foodborne, infant, wound, and a form of botulism whose classification is as yet undetermined. Certain foods have been reported as sources of spores in cases of infant botulism and the undetermined category; wound botulism is not related to foods. Foodborne botulism is the name of the disease (actually a food-borne intoxication) caused by the consumption of foods containing the neurotoxin produced by C. botulinum. Infant botulism, first recognized in 1976, affects infants under 12 months of age. This type of botulism is thought to be caused by the ingestion of C. botulinum spores which colonize and produce toxin in the intestinal tract of infants (toxico infectious botulism). Honey is the only implicated food source for C. botulinum spores. The number of confirmed infant botulism cases has increased significantly as a result of greater awareness by health officials since its recognition in 1976. It is now internationally recognized, with cases being reported in more countries. Wound botulism is the rarest form of botulism. The illness results when C. botulinum by itself or with other microorganisms infects a wound and produces toxins which reach other parts of the body via the blood stream. Foods are not involved in this type of botulism. Undetermined category of botulism involves adult cases in which a specific food or wound source cannot be identified. It has been suggested that some cases of botulism assigned to this category might result from intestinal colonization in adults, with in vivo production of toxin. Reports in the medical literature suggest the existence of a form of botulism similar to infant botulism, but occurring in adults. In these cases, the patients had surgical alterations of the gastrointestinal tract and/or antibiotic therapy. It is proposed that these procedures may have altered the normal gut flora and allowed C. botulinum to colonize the intestinal tract. 3. Nature of the Disease: Infective dose - a very small amount (a few nanograms) of toxin can cause illness. Onset of symptoms in foodborne botulism is usually 18 to 36 hours after ingestion of the food containing the toxin, although cases have varied from 4 hours to 8 days. Early signs of intoxication consist of marked lassitude, weakness and vertigo, usually followed by double vision and progressive difficulty in speaking and swallowing. Difficulty in breathing, weakness of other muscles, abdominal distention, and constipation may also be common symptoms. Clinical symptoms of infant botulism consist of constipation that occurs after a period of normal development. This is followed by poor feeding, lethargy, weakness, pooled oral secretions, and wail or altered cry. Loss of head control is striking. Recommended treatment is primarily supportive care. Antimicrobial therapy is not recommended. Infant botulism is diagnosed by demonstrating botulinal toxins and the organism in the infants' stools. 4. Diagnosis of Human Illness: Although botulism can be diagnosed by clinical symptoms alone, differentiation from other diseases may be difficult. The most direct and effective way to confirm the clinical diagnosis of botulism in the laboratory is to demonstrate the presence of toxin in the serum or feces of the patient or in the food which the patient consumed. Currently, the most sensitive and widely used method for detecting toxin is the mouse neutralization test. This test takes 48 hours. Culturing of specimens takes 5-7 days. 5. Associated Foods: The types of foods involved in botulism vary according to food preservation and eating habits in different regions. Any food that is conducive to outgrowth and toxin production, that when processed allows spore survival, and is not subsequently heated before consumption can be associated with botulism. Almost any type of food that is not very acidic (pH above 4.6) can support growth and toxin production by C. botulinum. Botulinal toxin has been demonstrated in a considerable variety of foods, such as canned corn, peppers, green beans, soups, beets, asparagus, mushrooms, ripe olives, spinach, tuna fish, chicken and chicken livers and liver pate, and luncheon meats, ham, sausage, stuffed eggplant, lobster, and smoked and salted fish. 6. Frequency: The incidence of the disease is low, but the mortality rate is high if not treated immediately and properly. There are generally between 10 to 30 outbreaks a year in the United States. Some cases of botulism may go undiagnosed because symptoms are transient or mild, or misdiagnosed as Guillain-Barre syndrome. 7. The Usual Course of Disease and Complications: Botulinum toxin causes flaccid paralysis by blocking motor nerve terminals at the myoneural junction. The flaccid paralysis progresses symmetrically downward, usually starting with the eyes and face, to the throat, chest and extremities. When the diaphragm and chest muscles become fully involved, respiration is inhibited and death from asphyxia results. Recommended treatment for foodborne botulism includes early administration of botulinal antitoxin (available from CDC) and intensive supportive care (including mechanical breathing assistance). 8. Target Populations: All people are believed to be susceptible to the foodborne intoxication. 9. Food Analysis Since botulism is foodborne and results from ingestion of the toxin of C. botulinum, determination of the source of an outbreak is based on detection and identification of toxin in the food involved. The most widely accepted method is the injection of extracts of the food into passively immunized mice (mouse neutralization test). The test takes 48 hours. This analysis is followed by culturing all suspect food in an enrichment medium for the detection and isolation of the causative organism. This test takes 7 days. 10. Recent Outbreaks: In the last 10 years, two separate outbreaks of botulism have occurred involving commercially canned salmon. Restaurant foods such as sauteed onions, chopped bottled garlic, potato salad made from baked potatoes and baked potatoes themselves have been responsible for a number of outbreaks. [Root crops, pattern?--LEB] Also, smoked fish, both hot and cold-smoke (e.g., Kapchunka) have caused outbreaks of type E botulism. In October and November, 1987, 8 cases of type E botulism occurred, 2 in New York City and 6 in Israel. All 8 patients had consumed Kapchunka, an uneviscerated, dry-salted, air-dried, whole whitefish. The product was made in New York City and some of it was transported by individuals to Israel. All 8 patients with botulism developed symptoms within 36 hours of consuming the Kapchunka. One female died, 2 required breathing assistance, 3 were treated therapeutically with antitoxin, and 3 recovered spontaneously. The Kapchunka involved in this outbreak contained high levels of type E botulinal toxin despite salt levels that exceeded those sufficient to inhibit C. botulinum type E outgrowth. One possible explanation was that the fish contained low salt levels when air-dried at room temperature, became toxic, and then were re-brined. Regulations were published to prohibit the processing, distribution and sale of Kapchunka and Kapchunka-type products in the United States. Most recently, a bottled chopped garlic-in-oil mix was responsible for three cases of botulism in Kingston, N.Y. Two men and a woman were hospitalized with botulism after consuming a chopped garlic-in-oil mix that had been used in a spread for garlic bread. The bottled chopped garlic relied solely on refrigeration to ensure safety and did not contain any additional antibotulinal additives or barriers. The FDA has ordered companies to stop making the product and to withdraw from the market any garlic-in-oil mix which does not include microbial inhibitors or acidifying agents and does not require refrigeration for safety. Since botulism is a life-threatening disease, FDA always initiates a Class I recall. The botulism outbreak associated with salted fish mentioned above is reported in greater detail in Mortality and Morbidity Weekly Report (MMWR) 36(49): 1987 Dec 18. A botulism type B outbreak in Italy associated with eggplant in oil is reported in MMWR 44(2):1995 Jan 20. An incident of foodborne botulism in Oklahoma is reported in MMWR 44(11): 1995 Mar 24. [Traced to a 3 day-old pot of beef stew left sitting at room temperature on the stove burner. Yikes!--LEB] In the late 1900's a MD in northern Canada was found guilty in the death of a young woman. Autopsy showed she died of botulism. The doctor misdiagnosed the problem and the patient died a couple of days later. Botulism is sneaky, deadly and not seem much anymore. Be VERY careful in your canning as the doctor treating you or your family just might make an error based on a lack of experience with said toxin. - ED. mow@vm.cfsan.fda.gov ---- Botulism poisoning is due to ingesting toxin(s) produced by the anaerobic bacterium _Clostridium botulinum_. There are seven isoforms of botulism toxins (Types A-G). Botulism toxins are colorless, odorless, and tasteless, but highly potent neurotoxins. To explain the physiology of the toxin a little farther, you might remember that nerve impulses are electrical signals (charge gradient that runs along the length of an axon), while the connection between muscles and nerves are mediated by chemical signals. The end of an axon releases synaptic vesicles filled with chemical neurotransmitters. These synaptic vesicles travel a short distance to the synaptic plate on muscle cells, then bind and release neurotransmitters. Current research indicates that botulism toxins bind and cleave several proteins on the outside of synaptic vesicles. Those vesicles cannot then bind to the next synaptic plate and unload the neurotransmitter. Thus, the connection between nerve and muscle impulses is cut biochemically, at the place where the chemical signal is delivered. Muscle control is lost, especially fine facial muscles. Symptoms of botulism toxin poisoning usually occur within 12-36 hrs after ingestion. They include muscle weakness, slurred speech, blurred vision (all fine muscle movements); followed by an inability to hold up the head. Death occurs by respiratory failure. If you recognize these symptoms after trying a canned food, call 911 immediately. Whoever is able should reclose the jar, wrap well, put in a ziploc bag, close, bring to the hospital. Wash your hands carefully after this procedure! [Other food poisoning symptoms are listed below in question IV.5--LEB] Treatment for botulism is straightforward. Often the antisera to the toxin is given, and the victim is placed on a respirator. Survival depends on the amount of toxin ingested, and how quickly the victim got treatment. Recovery is quite slow, taking months. The United States case/fatality rate has dropped in recent years, but the *number of cases* in the US increases slightly in proportion to the popularity of home canning. Interesting cultural comparison: botulism cases in Europe tend to come from cured meats, from Japan from salted fish, from the US from canned vegetables. 13.1.3 [I'm confused about when the toxin is produced. Tell me more about the bacterium.] There are three varieties of _C. botulinum_; 2 of these varieties (A, C) live and grow in soil under anaerobic (without oxygen) conditions, while 1 variety (E) can be found in fresh and saltwater, also under anaerobic conditions. Under aerobic (oxygen) conditions, all varieties of _C. botulinum_ encyst, producing a spore. Under normal *aerobic* conditions, both oxygen and your immune system take care of the few dormant spores that you meet in everyday life. NOTE: This is the dormant spore, *not* the bacterium. The bacterium is what you could find in a badly processed can. However, while the encysted, dormant form does *not* produce the toxin (only the bacterium does), the _C. botulinum_ spore is much more resistant to extreme conditions than the bacterium, making it harder to kill. Deadly problems can occur in situations where you attempt to preserve food by creating an *anerobic* state; namely, when you create a vacuum seal using heat and a 2-piece lid, sometimes when you preserve food in oil, or when you smoke meat. In each of those situations, the _C. botulinum_ spores can develop ("hatch" is a good way of thinking of it) into the bacterium, which then produce the toxin in your canned goods, oil, or on your smoked meat. For this reason, _C. botulinum_ spores in canned/smoked food must be killed or must be kept dormant. You, as a food preserver, using good common sense and a bag of tricks can accomplish this. 13.3.4 [How can I be absolutely, positively sure that those spores are killed?] You know, I think someone could make a mint by inventing the "home botulism test kit" that would work in the same way that a home pregnancy test kit does. But we don't, so... Remember, that despite the bacterium's fearsome reputation, _C. botulinum_ is still a microbe, and can be killed using a little basic microbiology. Preserving recipes utilize at least one of these 5 microbiological facts, good recipes often use several. 1. _C. botulinum_ bacterium dies at 212 F/ 100 C. 2. _C. botulinum_ spores die at 240 F/ 116 C. 3. Botulism toxin denatures at 185 F/ 85 C. **(All temperatures must be maintained for least 15 minutes, and the heat must be consistent throughout the food, fluid, and jar.)** 4. _C. botulinum_ spores cannot hatch in strong acid solutions of pH 4.6 or below. (Some sources claim pH 4.7.) 5. _C. botulinum_ cannot grow, develop, or multiply in food with a water content of less than 35%. (Food dehydrators have another set of toxic pests to worry about, see IV.6 about aflatoxin.) Common sense is a first step in the prevention of botulism. For instance: 1.) _C. botulinum_ bacteria and spores usually live in soil. Thus clean foods of soil, dust, grit, etc, using fresh, cold water. Change wash water often. Don't can "drops", fruit that has dropped to the ground. Pay special attention to cleaning root crops (including garlic!), shucking skins or peeling that produce if need be. 2.) One variety of _C. botulinum_ (E) lives in flat water. So, you want to make your brines, etc, with fresh cold water. Start with fresh, cold water if you are boiling to sterilize, or perform other operations. 3.) Botulism spores remain dormant under high acid conditions. Fruit is quite high in acid but also contains a lot of sugar, so the fruit still tastes sweet. Vinegar is added to vegetables to pickle them. You can can foods like this in a boiling waterbath. However, the concentration of acid (ionic strength) is also very important, so you want to use vinegars of a known strength (5% or 5 grain); add the recommended amount of vinegar, citric acid, or ascorbic acid described in your recipe; can just-ripe fruits. For safety's sake, you shouldn't cut down the amount of vinegar in a recipe, take a cue from fruit and add a little bit of sugar to cut down the extreme acid taste. Vegetable pickles should be immersed in the vinegar or brine. *BTW, finding out that honey is a source of botulism spores (infant botulism), means that I'm not thrilled about the idea of substituting honey for sugar, as the Rodale Institute appears to be.* 4.) Botulism spores, bacterium, and the toxin are killed by high heat. However, all the contents of the jar has to get to the target temperature, no matter the volume, and the temperature should be sustained for about 15 minutes. Follow recipes exactly, including jar sizes and treatment of the jars. Process at least for the times indicated, but remember that you have to increase processing time or pressures depending on your altitude. (Water boils at lower temperatures the higher your altitude.) Note that larger size jars usually require longer processing time, because the heat has to penetrate through the jar. Acid and heat are each used in canning things that are borderline acid, such as tomatoes, tomato vegetable mixes (like salsa and spaghetti sauce), vegetable relishes, and other vegetable mixes. The idea here is that you can't increase one thing to avoid other procedures. (You can't increase acid to avoid pressure canning). 5.) Botulism cannot grow or develop without water. In making jams or jellies, enough sugar and pectin is added to form a gel, depressing the amount of free water available for bacteria to grow. This is one of the reasons why special care has to be taken if the jam or jelly is extremely runny. Foods preserved in oil (raw garlic, chilis, dried tomatoes) create a special case. Oil contains no water, as it is centrifuged out during processing. If an item is dependably dry, under 35% water content, adding it to the oil should not cause problems, as long as your items are well immersed (1 inch of oil covering). Dry herbs, seeds and spices, dried chiles, even sundried tomatoes should not cause problems. (N.B: Research from the Australian Extension Service--sundried tomatoes are more acid than hydrated ones: pH 4.0 for dried, 4.6 for hydrated--LEB). However, the dehydrated food must be properly dried, conditioned, and not case hardened (case hardened things are hard and crunchy on the outside, soft and gooey on the inside). The jury is out on wet herbs. If you try to preserve a lot of "wet" items in oil (garlic cloves, chopped onions, ginger root, fresh chiles), you might have a heap of trouble. Oil doesn't contain much dissolved oxygen, so it is a good anaerobic medium. Raw garlic, onions, ginger are all rootcrops, and each contain over 35% water. Chilies often are added to oil in a non-dried state. Generally, you want to "pickle", or at least allow your wet, raw item to take up some 5% vinegar for about 15-20 minutes before putting into the oil. Chunky items (i.e. garlic cloves) should be smashed, crushed, or chopped to get the vinegar into the item. Simple, but through, sauteing of your chosen flavoring in your oil can also get rid of spores, since they evaporate free water, and the oil can be heated to above 240 F. Yet another idea is to refrigerate your flavored oils, as bacterial growth is very slow below 40 F/4 C. In addition, the garlic-in-oil botulism problem began when garlic pastes in olive oil were introduced in grocery stores. Many of the botulism poisonings occurred when these pastes were used in cold pasta, salads, and salad dressings. If you are going to be using your flavored oil for sauteing, stir fry, or deep fat frying you will easily heat your oil to above any of the target temperatures described above. Since the toxin is denatured at 185 F/85 C, if you are concerned about a canned good the usual procedure is as described in the above section (to hard boil the contents for 15 minutes). NOTE: This will denature the botulism toxin. Other toxins, such as those caused by _Staphococcus_, will not denature until temps of 240 F/116 C are reached and sustained for 30 minutes. As a matter of fact, a hard boil in that case will break open the bacteria, and more toxin would be released into the food. 13.1.5 [I don't feel so good. What do I have/had/will have?] This is a generalized list of food poisoning symptoms pulled from the Bad Bug Book on the FDA site: http://vm.cfsan.fda.gov/~mov/app2.html. [If you are actually in the throes of food poisoning, do not use this as a substitute for a doctor's diagnosis and care. I merely list this as a subject useful to food preserver--LEB.] Associated Onset time Predominant organism to symptoms symptoms or toxin __________________________________________________________________________ Upper gastrointestinal tract symptoms (nausea, vomiting) occur first or predominate: Less than 1 h Nausea, vomiting, unusual Metallic salts taste burning of mouth. 1-2 h Nausea, vomiting, cyanosis, Nitrites headache, dizziness, dyspnea, trembling, weakness, loss of consciousness. 1-6 h, mean Nausea, vomiting, retching, Staphylococcus aureus 2-4 h diarrhea, abdominal pain, and its enterotoxins prostration. 8-16 h Vomiting, abdominal cramps, Bacillus cereus (2-4 h emesis diarrhea, nausea. possible) 6-24 h Nausea, vomiting, diarrhea, Amanita species thirst, dilation of pupils, mushrooms collapse, coma. Sore throat and respiratory symptoms occur: 12-72 h Sore throat, fever, nausea, Streptococcus pyogenes vomiting, rhinorrhea, sometimes a rash. 2-5 days Inflamed throat and nose, Corynebacterium spreading grayish exudate, diphtheriae fever, chills, sore throat, malaise, difficulty in swallowing, edema of cervical lymph node. ______________ Lower gastrointestinal tract symptoms (abdominal cramps, diarrhea) occur first or predominate: 2-36 h, mean Abdominal cramps, diarrhea, Clostridium perfringens, 6-12 h putrefactive diarrhea Bacillus cereus, associated with C. perfringens, Streptococcus faecalis, sometimes nausea and vomiting. S. faecium 12-74 h, mean Abdominal cramps, diarrhea, Salmonella species 18-36 h vomiting, fever, chills, (including S. arizonae), malaise, nausea, headache, Shigella, enteropatho- possible. Sometimes bloody genic Escherichia coli, or mucoid diarrhea, cutaneous other Enterobacteriacae, lesions associated with V. Vibrio parahaemolyticus, vulnificus. Yersinia Yersinia enterocoliticia, enterocoliticia mimics Pseudomonas aeruginosa flu and acute appendicitis. (?),Aeromonas hydrophila, Plesiomonas shigelloides, Campylobacter jejuni, Vibriocholerae (Ol and non-Ol) V.vulnificus, V. fluvialis 3-5 days Diarrhea, fever, vomiting Enteric viruses abdominal pain, respiratory symptoms. 1-6 weeks Mucoid diarrhea (fatty stools) Giardia lamblia abdominal pain, weight loss. 1 to several Abdominal pain, diarrhea, Entamoeba histolytica weeks, constipation, headache, drowsiness, ulcers, variable -- often asymptomatic. 3-6 months Nervousness, insomnia, hunger Taenia saginata, pains, anorexia, weight loss, T. solium abdominal pain, sometimes gastroenteritis. ....---.... Neurological symptoms (visual disturbances, vertigo, tingling, paralysis) occur: Less than l h *** SEE GASTROINTESTINAL AND/OR Shellfish toxin NEUROLOGIC SYMPTOMS (Shellfish Toxins) (this Appendix) Gastroenteritis, nervousness, Organic phosphate blurred vision, chest pain, cyanosis, twitching, convulsions. Excessive salivation, perspir- Muscaria-type ation, gastroenteritis, mushrooms irregular pulse, pupils constricted, asthmatic breathing. Tingling and numbness, Tetradon (tetrodotoxin) dizziness, pallor, gastro- toxins hemmorrhage, and desquamation of skin, fixed eyes, loss of reflexes, twitching, paralysis. 1-6 h Tingling and numbness, gastro- Ciguatera toxin enteritis, dizziness, dry mouth, muscular aches, dilated pupils, blurred vision, paralysis. Nausea, vomiting, tingling, Chlorinated hydrocarbons dizziness, weakness, anorexia, weight loss, confusion. 2 h to 6 days, Vertigo, double or blurred Clostridium botulinum usually vision, loss of reflex to and its neurotoxins 12-36 h light, difficulty in swallowing. speaking, and breathing, dry mouth, weakness, respiratory paralysis. More than 72 h Numbness, weakness of legs, Organic mercury spastic paralysis, impairment of vision, blindness, coma. Gastroenteritis, leg pain, Triorthocresyl ungainly high-stepping gait, phosphate foot and wrist drop. ______________ Allergic symptoms (facial flushing, itching) occur: Less than 1 h Headache, dizziness, nausea, Histamine (scombroid) vomiting, peppery taste, burning of throat, facial swelling and flushing, stomach pain, itching of skin. Numbness around mouth, tingling Monosodium glutamate sensation, flushing, dizziness, headache, nausea. Flushing, sensation of warmth, Nicotinic acid itching, abdominal pain, puffing of face and knees. _____________ Generalized infection symptoms (fever, chills, malaise, prostration, aches, swollen lymph nodes) occur: 4-28 days, mean Gastroenteritis, fever, edema Trichinella spiralis 9 days about eyes, perspiration, muscular pain, chills, prostration, labored breathing. 7-28 days, mean Malaise, headache, fever, cough, Salmonella typhi 14 days nausea, vomiting, constipation, abdominal pain, chills, rose spots, bloody stools. 10-13 days Fever, headache, myalgia, rash. Toxoplasma gondii 0-50 days, Fever, malaise, lassitude, Etiological agent not mean 25-30 anorexia, nausea, abdominal yet isolated -- probably days pain, jaundice. viral Varying periods Fever, chills, head- or joint Bacillus anthracis, (depends on ache, prostration, malaise, Brucella melitensis, B. specific swollen lymph nodes, and other abortus, B. suis, Coxi- illness) specific symptoms of disease ella burnetii, Franci- in question. sella tularensis, Listeria monocytogenes, Mycobacterium tubercu- losis, Mycobacterium species, Pasteurella multocida, Strepto- bacillus moniliformis, Campylobacter jejuni, Leptospira species. Gastrointestinal and/or Neurologic Symptoms - (Shellfish Toxins): 0.5 to 2 h Tingling, burning, numbness, Paralytic Shellfish drowsiness, incoherent speech, Poisoning (PSP) respiratory paralysis. (saxitoxins) 2 - 5 min to Reversal of hot and cold Neurotoxic Shellfish 3 - 4 h sensation, tingling; numbness Poisoning (NSP) of lips, tongue & throat; muscle (brevetoxins) aches, dizziness, diarrhea, vomiting. 30 min to Nausea, vomiting, diarrhea, Diarrheic Shellfish 2 - 3 h abdominal pain, chills, fever Poisoning (DSP) (dinophysis toxin, okadaic acid, pecteno- toxin, yessotoxin) 24 h (gastroin- Vomiting, diarrhea, abdominal Amnesic Shellfish testinal) to pain, confusion, memory loss, Poisoning (ASP) 48 h disorientation, seizure, coma (domoic acid) (neurologic) _________________________________________________________________ Text last edited: 21 Jan 92 Hypertext last edited: 26 Jul 94mow@vm.cfsan.fda.gov 13.1.6 [Aflatoxin. What is it?] Food dehydrators have another set of toxic pests to worry about. While bacteria need free water to reproduce, molds can grow and spread, and de- velop their toxins under much drier conditions. The most famous mold is that of ergot, which when ingested causes hallucinations. The molds of most concern here are those of _Aspergillus_, which produces aflatoxin. The Bad Bug MO of aflatoxin is listed below. Aflatoxins U S Food & Drug Administration Center for Food Safety & Applied Nutrition Foodborne Pathogenic Microorganisms and Natural Toxins 1992 (Bad Bug Book) 1. Name of Toxin: Aflatoxins 2. Name of Acute Disease: Aflatoxicosis Aflatoxicosis is poisoning that results from ingestion of aflatoxins in contaminated food or feed. The aflatoxins are a group of structurally re- lated toxic compounds produced by certain strains of the fungi _Aspergillus flavus_ and _A. parasiticus_. Under favorable conditions of temperature and humidity, these fungi grow on certain foods and feeds, resulting in the production of aflatoxins. The most pronounced contamination has been encoun- tered in tree nuts, peanuts, and other oilseeds, including corn and cotton- seed. 2. Aflatoxins: The major aflatoxins of concern are designated B1, B2, G1, and G2. These toxins are usually found together in various foods and feeds in various pro- portions; however, aflatoxin B1 is usually predominant and is the most toxic. When a commodity is analyzed by thin-layer chromatography, the aflatoxins separate into the individual components in the order given above; however, the first two fluoresce blue when viewed under ultraviolet light and the second two fluoresce green. [Could a black light be useful to monitor dried items?--LEB]. Aflatoxin M a major metabolic product of aflatoxin B1 in animals and is usually excreted in the milk and urine of dairy cattle and other mammalian species that have consumed aflatoxin-contaminated food or feed. 3. Nature of Disease: Aflatoxins produce acute necrosis, cirrhosis, and carcinoma of the liver in a number of animal species; no animal species is resistant to the acute toxic effects of aflatoxins; hence it is logical to assume that humans may be similarly affected. A wide variation in LD50 values has been obtained in animal species tested with single doses of aflatoxins. For most species, the LD50 value ranges from 0.5 to 10 mg/kg body weight. Animal species respond differently in their susceptibility to the chronic and acute toxicity of aflatoxins. The toxicity can be influenced by environmental factors, expo- sure level, and duration of exposure, general health, and nutritional status of diet. Aflatoxin B1 is a very potent carcinogen in many species, including nonhuman primates, birds, fish, and rodents. In each species, the liver is the primary target organ of acute injury. Metabolism plays a major role in determining the toxicity of aflatoxin B1; studies show that this aflatoxin requires meta- bolic activation to exert its carcinogenic effect, and these effects can be modified by induction or inhibition of the mixed function oxidase system. 4. Normal Course of Disease: In well-developed countries, aflatoxin contamination rarely occurs in foods at levels that cause acute aflatoxicosis in humans. In view of this, studies on human toxicity from ingestion of aflatoxins have focused on their carcin- ogenic potential. Therelative susceptibility of humans to aflatoxins is not known, even though epidemiological studies in Africa and Southeast Asia, where there is a high incidence of hepatoma, have revealed an association between cancer incidence and the aflatoxin content of the diet. These studies have not proved a cause-effect relationship, but the evidence suggests an association. One of the most important accounts of aflatoxicosis in humans occurred in more than 150 villages in adjacent districts of two neighboring states in northwest India in the fall of 1974. According to one report of this out- break, 397 persons were affected and 108 persons died. In this outbreak, contaminated corn was the major dietary constituent, and aflatoxin levels of 0.25 to15 mg/kg were found. The daily aflatoxin B1 intake was estimated to have been at least 55 ug/kg body weight for an undetermined number of days. The patients experienced high fever, rapid progressive jaundice, edema of the limbs, pain, vomiting, and swollen livers. One investigator reported a pe- culiar and very notable feature of the outbreak: the appearance of signs of disease in one village population was preceded by a similar disease in domes- tic dogs, which was usually fatal. Histopathological examination of humans showed extensive bile duct proliferation and periportal fibrosis of the liver together with gastrointestinal hemorrhages. A 10-year follow-up of the Indian outbreak found the survivors fully recovered with no ill effects from the experience. A second outbreak of aflatoxicosis was reported from Kenya in 1982. There were 20 hospital admissions with a 60% mortality; daily aflatoxin intake was estimated to be at least 38 ug/kg bodyweight for an undetermined number of days. In a deliberate suicide attempt, a laboratory worker ingested 12 ug/kg body weight of aflatoxin B1 per day over a 2-day period and 6 months later, 11 ug/kg body weight per day over a 14-day period. Except for transient rash, nausea and headache, there were no ill effects; hence, these levels may serve as possible control levels for aflatoxin B1 in humans. In a 14-year follow-up, a physical examination and blood chemistry, including tests for liver function, were normal. 5. Diagnosis of Human Illnesses: Aflatoxicosis in humans has rarely been reported; however, such cases are not always recognized. Aflatoxicosis may be suspected when a disease out- break exhibits the following characteristics: - the cause is not readily identifiable - the condition is not transmissible - syndromes may be associated with certain batches of food - treatment with antibiotics or other drugs has little effect - the outbreak may be seasonal, i.e., weather conditions may affect mold growth. The adverse effects of aflatoxins in animals (and presumably in humans) have been categorized into two general forms. A. (Primary) Acute aflatoxicosis is produced when moderate to high levels of aflatoxins are consumed. Specific, acute episodes of disease ensue may include hemorrhage, acute liver damage, edema, alteration in digestion, absorption and/or metabolism of nutrients, and possibly death. B. (Primary) Chronic aflatoxicosis results from ingestion of low to moderate levels of aflatoxins. The effects are usually subclinical and dif- ficult to recognize. Some of the common symptoms are impaired food conver- sion and slower rates of growth with or without the production of an overt aflatoxin syndrome. 6. Associated Foods: In the United States, aflatoxins have been identified in corn and corn pro- ducts, peanuts and peanut products, cottonseed, milk, and tree nuts such as Brazil nuts, pecans, pistachio nuts, and walnuts. Other grains and nuts are susceptible but less prone to contamination. 7. Relative Frequency of Disease: The relative frequency of aflatoxicosis in humans in the United States is not known. No outbreaks have been reported in humans. Sporadic cases have been reported in animals. 8. Target Populations: Although humans and animals are susceptible to the effects of acute afla- toxicosis, the chances of human exposure to acute levels of aflatoxin is remote in well-developed countries. In un-developed countries, human sus- ceptibility can vary with age, health, and level and duration of exposure. 9. Analysis of Foods: Many chemical procedures have been developed to identify and measure afla- toxins in various commodities. The basic steps include extraction, lipid removal, cleanup, separation and quantification. Depending on the nature of the commodity, methods can sometimes be simplified by omitting unnecessary steps. Chemical methods have been developed for peanuts, corn, cottonseed, various tree nuts, and animal feeds. Chemical methods for aflatoxin in milk and dairy products are far more sensitive than for the above commodities because the aflatoxin M animal metabolite is usually found at much lower levels (ppb and ppt). All collaboratively studied methods for aflatoxin anal- ysis are described in Chapter 26 of the AOAC Official Methods of Analysis. 10. History of Recent Outbreaks: Very little information is available on outbreaks of aflatoxicosis in humans because medical services are less developed in the areas of the world where high levels of contamination of aflatoxins occur in foods, and, therefore, many cases go unnoticed. Text last edited: 21 Jan 92 Hypertext last edited: 19 Apr 95 mow@vm.cfsan.fda.gov (end of part 5)