THE EMETOPHOBES' GUIDE
TO (AVOIDING) FOOD POISONING
Eating or drinking food or drink contaminated with viruses,
bacteria or toxins can produce the symptoms of food poisoning any emetophobe
absolutely dreads - stomach/abdominal pains, nausea, vomiting, fever and
diarrhoea. Symptoms can start within just 30 minutes (chemical poisoning) or up
to 48 hours after ingesting infected food.
Different types of food poisoning include:
BACILLUS CEREUS: This is a common bug found in vegetables and grains such as rice. If boiled rice is left standing in a hot kitchen then any spores which survived cooking will be able to germinate and multiply prior to being served with a meal.
CAMPYLOBACTER: This is the most common form of food poisoning in the UK with 43,000 cases reported in the UK in 1996 and is on the increase (only 30,000 cases reported in 1980).
It is found in contaminated poultry which is inadequately cooked, under-cooked meat which is still red or pink inside, unpasteurised milk and even in water. It can be transmitted into other foods by cross-contamination, such as poultry touching cooked, ready-to-eat food.
Once the bacteria has been ingested it multiplies in the stomach to produce milder symptoms of nausea and vague stomach pains with, possibly, a fever for a day or so. Then the main symptoms (nausea, diarrhoea, vomiting, abdominal pains) usually appear between 3-10 days after eating the suspect food. The illness lasts for 5-10 days with a further period of a week or two as the bacteria is finally eliminated from the body.
BOTULISM: The name derives from Latin botulus meaning sausage which is one of the main sources of botulism, along with processed meats and canned vegetables which have not been adequately heated.
It is a tough bacterium which survives both heat and dry conditions by changing into spores which remain dormant until meeting optimum breeding conditions of warmth, moisture, nutrients and an absence of oxygen - ie conditions found within the centre of a sausage.
Once ingested, the toxin moves through intestinal walls into the lymphatic system and into the blood-stream in which it is transported around the entire body. This process can take between 12-24 hours, after which the patient becomes ill as the junctions between nerves and muscles are impaired. Symptoms of poisoning by the clostridium botulinum toxin progressively include nausea (sometimes followed by vomiting or diarrhoea - but not always), dry mouth, dizziness, blurred/double vision, paralysis of limb muscles, difficulty speaking and swallowing then difficulty breathing as chest muscle function becomes impaired. Although patients become paralysed, their level of consciousness and senses are nearly normal. It is very difficult to repair the damage done in bad cases and it can be fatal.
Eight different types of the toxin exist - types A, B, C, D, E and so on which vary in their heat resistance. In order to minimise chances of ingesting either, food should be heated (and reheated if allowed to chill between the initial cooking and during storage) to 80 C for up to 10 minutes for types A and B while type E, associated with fish, salmon and vacuum-packed fish must be heated up to 60 C for 5 minutes.
CLOSTRIDIUM PERFRINGENS: is more common but far less severe than clostridium botulinum and is found in meats (especially mince or meat pies) and is entirely avoidable by adequate cooking. Food such as stews cooked in a large saucepan and allowed to cool very slowly or kept luke-warm overnight in a kitchen provides the ideal breeding ground for the spores to multiply. The toxin damages the intestines and leads to severe diarrhoea for 12-18 hours after ingestion. To avoid altogether : ensure food is not allowed to stand at temperatures between 30-50 C for longer than an hour to ensure the bacteria cannot breed at a dangerous level. Any re-heating must be thorough to avoid food-poisoning.
STAPHYLOCOCCUS AUREUS: Staphylococci are small, rounded bacteria which everyone carries on their body, particularly on our skin and up our nostrils. Not all the bacteria causes food poisoning but there is no easy way for a lay-person to spot which are the dangerous ones, hence care must be taken to ensure food does not become contaminated by our own bacteria.
If bacteria do get into food then, under ideal breeding conditions of warmth and moisture, they multiply in large numbers releasing high levels of toxin into food. The foods most likely to be affected are meats (especially chicken), creams, custards and baked products containing a filling such as the dodgy vol-au-vents often served at buffets, parties and other social functions.
The toxin is rapidly absorbed and appears to travel up from the stomach to the brain where it triggers the vomiting centre in the brain and causes vomiting within 30 minutes to 3 hours after eating the contaminated food.
As the toxin is resistant to normal cooking, re-heating will not make dangerous/contaminated food safe hence it is vital to ensure it does not become infected in the outset.
LISTERIOSIS: is especially associated with salads (where vegetables are added to dressings or mayonnaise and then refrigerated for several days afterwards since the toxin thrives in low temperatures), Soft Cheeses, Salamis and other processed meats (which may be contaminated with listeria before or following manufacture) and long storage in refrigerators provides an ideal breeding ground for the toxin and cook-chill foods. This involves an initial cooking of food to 70 C at which all but the spores of bacteria should be destroyed. The food is then rapidly chilled to prevent any bacteria growing. However, the initial cooking may fail to kill all bacteria, foods could be stored at too high a temperature during transportation or in the retail outlet or at home in the domestic refrigerator. Especially risky are pre-cooked chickens which can stay on supermarket shelves for several days and then in the domestic fridge for an additional few days.
Symptoms of Listeriosis include fever, flu-like symptoms and muscle pains.
SALMONELLA: is one of the most widely studied forms of food poisoning. The natural hosts of salmonella are birds although it can also be present in cattle, pigs and veal calves.
Chickens are especially risky since salmonella can get into hens' ovaries and contaminate the bird. As eggs are layed they can also pick up specks of the hens' droppings which may contaminate the egg shell. Eggs should, therefore, be stored separately from other foods in the fridge and hands should be washed after handling eggs. Since the eggshell is permeable to water, it is NOT advisable to actually wash eggs. Meticulous personal/food hygiene should ensure there is no hand to mouth infection.
Symptoms including nausea, colicky, spasmodic abdominal pains followed by urgent and frequent greenish diarrhoea, hot or cold sweats and, sometimes, vomiting. The illness reaches a peak after 6 hours but it can take several weeks to make a full recovery. In serious cases, salmonella can get into the bloodstream causing septicaemia with a high temperature, collapse and breathing difficulties which can be fatal.
VIRUSES: These are the smallest
infectious agents identified to
date. If a virus is eaten then it can cause a
disease very similar to food poisoning with symptoms of nausea, vomiting,
diarrhoea, often termed gastro-enteritis. Of most concern to emetophobes is that
the virus can, potentially, be airborne thus making it extremely difficult to
avoid. The most common problem with viruses is seen in hospitals, nursing homes
and areas where large numbers of people are clustered together, especially in a
warm and humid atmosphere, whereby over a period of a few weeks the illness will
be contracted by people in turn.
If somebody suffers from projectile vomiting, small round-structured viruses (SRSV's) can be inhaled - just another reason to keep away from anyone doing the dreaded . . . .
ESHERICA COLI - the topical issue. This bug lives in the human bowel where it does not normally cause problems. However, in 1995 a gene mutated causing E Coli to become increasingly toxic, now referred to as E Coli 0157. It is found in under-cooked meats, particularly mince where a small portion of contaminated meat is mixed with larger portions of uncontaminated meat thus infecting the entire batch. Adequate cooking will destroy the bug and much E coli can be avoided by steering clear of pre-cooked meats where the cooking time and temperature is unknown and undercooked burgers which are still red/pink inside. It can take many months to thoroughly eradicate the E Coli infection which is treated with antibiotics (remember some bugs are now becoming resistant to anti-biotics) and the symptoms of nausea, 'mega-vomiting', diarrhoea etc can be intense for up to about 2 months. The Scottish outbreak killed 20 people within a short timespan whilst normally only 4 people per year would die from it.
FLIES: can be a source of infection. They eat by pumping saliva over food which then digests food externally and the resulting fluid is then sucked back by the fly who might also defecate on the food surface. Hence it is vital to always keep foods covered.
SHELLFISH: absorb chemicals and bacteria from the water in which they live and bacteria and viruses can stick to their skin. They should be carefully washed and, ideally, adequately cooked although some people prefer to eat oysters raw. It is a good idea to immerse shellfish in boiling water for a few minutes then rapidly cool them if they are to be served cold. They can carry viruses which cause vomiting, diarrhoea and hepatitis.
Refrigerators should be operated at under 3 degrees centigrade (buy a fridge thermometer) and a rise in temperature from 4 C to 8 C can increase the rate of bacterial growth by 65%. Reheating or under-cooking food can also encourage bacterial growth which peaks in the optimum temperature range of 8 c to 60 C, the mid-point being around 37 C - ie Body Temperature!
FOOD HYGIENE/SAFETY TIPS!
KITCHEN HYGIENE
 | keep raw and cooked foods separate |
| ensure fridge temperature is below 3-5 C |
| ensure freezer temperature is at/below -18 C (ideally at minus 22 deg C) |
| wash hands before preparing food and after touching any possible source of contamination- dustbins, door handles, eggs, raw meat/fish, your nose or mouth |
| do not touch sink taps, fridge door handles etc with contaminated fingertips as these will then become a source of contamination every time they are used |
| replace dish cloths daily (or bleach/boil daily), wash after use and store as dry as possible |
| when washing up, remove all visible traces of food, wash in hot water (use rubber gloves to allow a high temperature to be used), allow washing up to dry naturally then buff it up using a tea towel |
| replace tea-towels regularly - a damp one is an ideal bacteria breeding ground |
| do not delve through cutlery drawers etc with dirty hands or you will contaminate everything you touch! |
| thaw and store chickens/raw meat etc at the lowest point in the fridge so that it will not drip onto other foods |
| change hand towels daily to avoid build-up of bacteria and moisture |
| keep soap bars as dry as possible to avoid bacterial growth - or use liquid soap in a dispenser |
| promptly dispose of rubbish and food waste in which bacteria thrive and vermin are attracted to |
| surfaces and chopping boards used to prepare raw foods should be mopped with kitchen roll then thoroughly washed. Plastic chopping boards are easier to keep clean than wooden ones although it is thought that wooden boards may contain as natural antibacterial agent. |
| keep all food covered to ensure it cannot be contaminated by flies |
| use separate plates for pets which are often carriers of campylobacter |
| do not buy dirty or eggs with cracked shells; store eggs in the fridge to discourage bacteria growth; wash your hands after handling eggs and never eat uncooked eggs |
THE MAIN RISKS
| inadequately cooked food - use a food thermometer if in doubt but clean it before each use otherwise you could be introducing new bacteria every time you insert it! |
| food prepared in advance and kept at room temperature- thus allowing bacteria to multiply |
| inadequate thawing of raw foods (eg chicken and turkey) |
| unless the pack states the product CAN be cooked from frozen, food should be thoroughly defrosted before cooking |
| cross-contamination from raw to cooked foods |
| handling food when infected with food poisoning bacteria |
| Cornish pasties, sandwiches and meat pies - often stored at room temperature rather than refrigerated |
| food kept warm (but not hot enough) under strong lights eg canteens, motorway services |
| kebabs - uncooked slices can be served; re-heating is common and may be inadequate |
| take-away food (especially Indian or Chinese) prepared out of sight, kept hot for long periods or inadequately re-heated in microwave ovens |
| mayonnaise - possibly made from under-cooked/raw eggs; storage temperatures unknown |
| restaurant soup - could be made from previous day's left-overs; but usually OK if tinned or powdered |
| sauces containing egg yokes |
| buying frozen/chilled foods and leaving them in a warm car/kitchen prior to correctly storing/preparing |
| raw meat and fish should always be stored at the bottom of the fridge to prevent any fluids dripping onto cooked/ready-to-serve food below |
| Remember : cooked meat, fish, eggs and dairy products should never be kept in warm surroundings for more than 2 hours |
| Pets must ALWAYS be banned from the kitchen and cats never allowed to roam on worktops where food is prepared. |
RELATIVELY SAFE FOODS
| cooked vegetables and well-washed salads |
| dry, salty foods such as nuts, crisps, anchovies and olives |
| fresh fruit (washed/peeled), fruit juice, jam, pickles, bread and biscuits are too acidic, too sugary or too dry to allow bacteria to multiply |
| tinned foods are usually subjected to sufficient heat to kill bacteria BUT the can must be undamaged and with no dents or rust |
| dried foods |
| fish and chips from fish and chip shops - cooked to order in hot fat from fresh or frozen (not reheated) ingredients |
| frozen foods which are transferred to the home freezer within less than an hour (less in hot weather) |
| Most foods which are fried or grilled and immediately eaten are OK since they are subjected to high temperatures (but ensure they are cooked right through) |
| fish has to be transported on ice or it rapidly goes off. As it cooked at a high temperature and promptly served, the risks are reduced |
AVOID cold buffet foods: cream cakes, cooked meats, pate etc which have been on display for some time in a warm room/marquee, sandwiches served from a counter in direct sun or an overheated shop, partially-cooked barbecue food (best to pre-cook it in a microwave and 'brown' it on the barbecue to finish it off), ice cream made from unpasteurised milk, quiches, casseroles and vol-au-vents - these must be piping hot right through when they are served, foods which are handled (or later fingered) by a lot of people
I hope reading this has not put you off your next meal!
Antibiotics can help recovery from food-poisoning and reduce the duration of suffering diarrhoea and vomiting from 50 hours to 25 - or less. A single 500mg dose of ciprofloxacin (Ciproxin) can reduce the number of trips to the loo from 11 to 5 and potentially fewer if you take a diarrhoea remedy such as loperamide in addition.
Further information about food hygiene/poisoning is available at : www.fightbac.org and www.foodsafety.gov Please note, these are not Gut Reaction pages