Food Poisoning.                                       

The sickening facts.

Firstly any one can get "food poisoning", no one is immune.

Secondly poor food hygiene is the main cause.

Now here are some of the details:

Each year it is estimated that as many as 5.5 million people in the UK may suffer from food borne illnesses – that’s 1 in 10 people. This section explains what food poisoning is and describes some of the most common organisms that cause it............. "the usual suspects".

Food poisoning organisms found in food  are very hard to detect since they do not usually affect the taste, appearance or smell of food.

Food poisoning is more likely to affect people with lowered resistance to disease than healthy people who might show mild symptoms or none at all. Elderly or sick people, babies, young children and pregnant women are particularly vulnerable to food poisoning and should seek treatment if they have symptoms.

Chemicals, heavy metals, parasites, fungi, viruses and bacteria can cause food borne illness. Bacteria related food poisoning is the most common, but fewer than 20 of the many thousands of different bacteria actually are the culprits. More than 90% of the cases of food poisoning each year are caused by Staphylococcus aureus, Salmonella, Clostridium perfringens, Campylobacter, Listeria monocytogenes, Vibrio parahaemolyticus, Bacillus cereus, and Entero-pathogenic Escherichia coli. 

These bacteria are commonly found on many raw foods. Normally a large number of food-poisoning bacteria must be present to cause illness. Therefore, illness can be prevented by:

1) controlling the initial number of bacteria present, 

2) preventing the small number from growing, 

3) destroying the bacteria by proper cooking,

4) avoiding re-contamination.

 

Information on the main causes of food poisoning:

 

SALMONELLA                            SALMONELLA
Disease: Salmonellosis
Source: Spread when contaminated food (meat, poultry, eggs) is eaten raw or undercooked. Also, when cooked food comes in contact with contaminated raw food, or when an infected person prepares food.
Symptoms (after eating): Onset: 6-48 hours; nausea, fever, headache, abdominal cramps, diarrhoea, and vomiting lasting 2-7 days. Can be fatal to infants, the elderly, the infirm, and the immune-compromised.
Prevention: Separate raw foods from cooked foods. Thoroughly cook meat, poultry, and eggs. Consume only pasteurised  milk, dairy products, and egg nog. Don't leave food at room temperature over 2 hours. Refrigerate below 5 degrees C.

STAPHYLOCOCCUS AUREUS    STAPHYLOCOCCUS AUREUS
 Disease: Staph
Source: Carried by people on skin, in boils, pimples, and throat infections; spread when carriers handle food. Staph bacteria produce toxins (poisons) at warm temperatures. Meat, poultry, salads, cheese, eggs, custards, and cream-filled desserts are susceptible foods.
Symptoms (after eating): Onset: 1-8 hours; vomiting, diarrhoea, nausea, and abdominal cramps lasting 1-2 days. Rarely fatal.
Prevention: Cooking won't destroy staph poison, so practice good personal hygiene and sanitary food handling. Don't leave perishable food unrefrigerated over 2 hours. For quick cooling, place hot food in small containers no more than 4 inches deep; cover when cool and refrigerate.

CLOSTRIDIUM BOTULINUM       
Disease: Botulism
Source: Most common in low acid foods canned improperly at home. The presence of these bacteria or their poisons is sometimes signalled by clear liquids turned milky, cracked jars, loose or dented lids, swollen or dented cans, or an "off" odour. Recently, botulism has also been associated with low oxygen cooked foods (i.e. foil wrapped; vacuum packaged) which have been held at room temperatures for long periods of time.
Symptoms (after eating): Onset: 4-72 hours; nervous system disturbances such as double vision, droopy eyelids, trouble speaking, swallowing, breathing. Untreated botulism can be fatal. If you or a family member have botulism symptoms, get medical help immediately. Then call health authorities.
Prevention: Carefully examine canned goods (particularly those canned at home), and don't use any canned goods showing danger signs. Also, cook and reheat foods thoroughly, keep cooked foods hot (above 60 degrees C) or cold (below 5 degrees C) and divide large portions of cooked food into smaller portions for serving and cooling.

CLOSTRIDIUM PERFRINGENS           
Disease: Perfringens food poisoning
Source: "Buffet germ" that grows rapidly in large portions of food that cool slowly. It grows in chafing dishes which may not keep food sufficiently hot and in the refrigerator if food is stored in portions too large to cool quickly.
Symptoms (after eating): Onset: 8-24 hours; diarrhoea, gas pains, nausea, and sometimes vomiting lasting only a day. Usually mild, but can be serious in ulcer patients, the elderly, ill, or immune-compromised.
Prevention: Keep food hot (above 60 degrees C) or cold (below 5 degrees C). Divide bulk cooked foods into small portions for serving and cooling. Reheat leftovers to at least 75 degrees C. Take special care with poultry, stew, soup, gravy, and casseroles.

CAMPYLOBACTER JEJUNI           
Disease: Campylobacteriosis
Source: Contracted from untreated drinking water, infected pets, and when contaminated meat, poultry, milk, or shellfish is eaten raw or undercooked. Symptoms (after eating): Onset: 2-10 days; severe diarrhoea (possibly bloody), cramps, fever, and headache lasting 1-10 days.
Prevention: Don't drink untreated water or unpasteurised milk. Wash hands, utensils and surfaces that touch raw poultry or meat. Thoroughly cook meat, poultry, and seafood.

LISTERIA MONOCYTOGENES       
Disease: Listeriosis
Source: Common in nature, food processing environments, and intestinal tracts of humans and animals. Spread in untreated water, unpasteurised milk and dairy products, raw meat and seafood, plus raw vegetables fertilized with infected manure.
Symptoms (after eating): Onset: 2-30 days. Adults can develop fever, chills, and intestinal flu-like symptoms. Infants may vomit, refuse to drink, or have trouble breathing. Possible complications-meningitis, meningo-encephalitis, blood poisoning, spontaneous abortion, stillbirths. Rare, but can be fatal. Pregnant women, newborns, the elderly, infirm, and immune-compromised are most at risk.
Prevention: Avoid raw milk and cheese made from unpasteurised milk. Follow keep refrigerated labels, observe sell by and use by dates, and thoroughly reheat frozen or refrigerated processed meat and poultry products before eating. Listeria monocytogenes is a special problem since it can survive adverse conditions. It can grow in a pH range of 5.0-9.5 in good growth medium. The organism has survived the pH 5 environment of cottage cheese and ripening cheddar. It is salt tolerant surviving concentrations as high as 30.5 % for 100 days at 4 degrees C, but only 5 days if held at 37C.

SHIGELLA BACTERIA       
Disease: Shigellosis
Source: Spread when human carrier with poor sanitary habits handles liquid or moist food that is not thoroughly cooked afterwards. Shigella multiply at room temperature. Susceptible foods include poultry, milk and dairy products, salads, and other foods that require a lot of mixing and handling and no further heat treatment.
Symptoms (after eating): Onset: 1-7 days; abdominal pain, diarrhoea, fever, sometimes vomiting, and blood, pus or mucus in stool; lasts 5-6 days. Most serious in infants, the elderly, infirm, or immune-compromised.
Prevention: Practice good personal hygiene and sanitary food handling (wash hands thoroughly and frequently). Also, avoid leaving perishable foods unrefrigerated over 2 hours and cook food thoroughly (reheat to at least 75 degrees C). Do not prepare food when ill with diarrhoea or vomiting.

ESCHERICHIA COLI O157:H7       
Disease: Hemorrhagic colitis
Source: Serotype 0157:H7 toxin contracted by drinking water which contains raw sewage (usually during travel). Also, can occur in raw or rare ground beef and unpasteurised milk.
Symptoms (after eating): Onset: 3-4 days; severe abdominal cramps followed by diarrhoea (often bloody), nausea, vomiting, fever lasting to 10 days. May require hospitalisation. Possible complication-Hemolytic Uremic Syndrome (HUS), a urinary tract infection capable of causing kidney failure in children.
Prevention: Don't drink untreated water or unpasteurised milk. Thoroughly cook food and reheat it to at least 75degrees C. Don't leave perishable food unrefrigerated over 2 hours.


Viruses


HEPATITIS A                           
Disease: Infectious hepatitis
Source: Contracted when shellfish, harvested from water polluted by raw sewage, is eaten raw. Also spread by human carriers who prepare and serve uncooked food.
Symptoms (after eating): Onset: 14-50 days; fatigue, fever, nausea, vomiting, abdominal cramps, appetite loss, followed by liver enlargement, jaundice, and darkened urine. May cause liver damage and death.
Prevention: Avoid untreated drinking water and cook shellfish thoroughly. Also, practice good personal hygiene, handle all foods in a sanitary manner, and keep raw and cooked foods separated.

NOROVIRUSES                       
Disease: Viral gastroenteritis
Source: A group of viruses contracted when contaminated shellfish is eaten raw or partially cooked. Also, spread by infected people who prepare food when they are ill with these viruses.
Symptoms (after eating): Onset: 24-48 hours; diarrhoea, vomiting, nausea, abdominal cramps, fever, chills, and body aches.
Prevention: Cook shellfish thoroughly. Practice good personal hygiene and handle food in sanitary manner. Do not prepare or serve food when ill with diarrhoea or vomiting.

Moulds               
                                                            

MYCOTOXINS
Disease: Mycotoxicosis
Source: Many foods are susceptible to a wide variety of moulds. Some mycotoxins (poisons produced by moulds) can be harmful if consumed in large amounts. When it occurs, mycotoxicosis is usually traced back to beans, peanuts, corn, and other grains that have been stored in warm moist places.
Symptoms (after eating): May cause liver and/or kidney disease. (This depends on the amount of mycotoxin and length of exposure.)
Prevention: Store foods properly, and check for visible mould and "off" colour, odour, or texture. Discard contaminated food and clean container or storage area. (Hard cheeses, salami, or dry cured country ham may be salvaged by cutting out an inch of product on all sides and below the mouldy area.)


The basic rules for preparing food hygienically?

 

What should I do if I get sick?

Consult your family doctor. Think about what foods you have eaten in the last few days. Drink plenty of water to avoid dehydration. If the doctor diagnoses food poisoning report your illness to your local authority Environmental Health Officer. Prompt investigation may prevent other people suffering. Refrigerate any foods suspected of having caused illness. They may be needed for further analysis to determine what caused your illness. As far as possible do not handle or prepare food while you have the symptoms. Wash your hands thoroughly with soap and hot water before handling food. If you work in the food industry notify your employer. Unfortunately, it is estimated that less than 10% of all food poisoning incidents are reported

 

Shellfish Poisoning.           

Shellfish poisoning is caused by a group of toxins elaborated by planktonic algae (dinoflagellates, in most cases) upon which the shellfish feed. The toxins are accumulated and sometimes metabolised by the shellfish. The 20 toxins responsible for paralytic shellfish poisonings (PSP) are all derivatives of saxitoxin. Diarrheic shellfish poisoning (DSP) is presumably caused by a group of high molecular weight polyethers, including okadaic acid, the dinophysis toxins, the pectenotoxins, and yessotoxin. Neurotoxic shellfish poisoning (NSP) is the result of exposure to a group of polyethers called brevetoxins. Amnesic shellfish poisoning (ASP) is caused by the unusual amino acid, domoic acid, as the contaminant of shellfish.

 

Types of Shellfish Poisoning.

 

Ingestion of contaminated shellfish results in a wide variety of symptoms, depending upon the toxins(s) present, their concentrations in the shellfish and the amount of contaminated shellfish consumed. In the case of PSP, the effects are predominantly neurological and include tingling, burning, numbness, drowsiness, incoherent speech, and respiratory paralysis. Less well characterised are the symptoms associated with DSP, NSP, and ASP. DSP is primarily observed as a generally mild gastrointestinal disorder, i.e., nausea, vomiting, diarrhea, and abdominal pain accompanied by chills, headache, and fever. Both gastrointestinal and neurological symptoms characterise NSP, including tingling and numbness of lips, tongue, and throat, muscular aches, dizziness, reversal of the sensations of hot and cold, diarrhoea, and vomiting. ASP is characterised by gastrointestinal disorders (vomiting, diarrhoea, abdominal pain) and neurological problems (confusion, memory loss, disorientation, seizure, coma).

All shellfish (filter-feeding molluscs) are potentially toxic. 

However, PSP is generally associated with mussels, clams, cockles, and scallops; 

NSP with shellfish harvested along the Florida coast and the Gulf of Mexico; 

DSP with mussels, oysters, and scallops, and ASP with mussels.

 

Relative Frequency of Disease: 

Good statistical data on the occurrence and severity of shellfish poisoning are largely unavailable, which undoubtedly reflects the inability to measure the true incidence of the disease. Cases are frequently misdiagnosed and, in general, infrequently reported. Of these toxicoses, the most serious from a public health perspective appears to be PSP. The extreme potency of the PSP toxins has, in the past, resulted in an unusually high mortality rate.

Course of Disease and Complications: 

PSP: Symptoms of the disease develop fairly rapidly, within 0.5 to 2 hours after ingestion of the shellfish, depending on the amount of toxin consumed. In severe cases respiratory paralysis is common, and death may occur if respiratory support is not provided. When such support is applied within 12 hours of exposure, recovery usually is complete, with no lasting side effects. In unusual cases, because of the weak hypotensive action of the toxin, death may occur from cardiovascular collapse despite respiratory support.

NSP: Onset of this disease occurs within a few minutes to a few hours; duration is fairly short, from a few hours to several days. Recovery is complete with few after effects; no fatalities have been reported.

DSP: Onset of the disease, depending on the dose of toxin ingested, may be as little as 30 minutes to 2 to 3 hours, with symptoms of the illness lasting as long as 2 to 3 days. Recovery is complete with no after effects; the disease is generally not life threatening.

ASP: The toxicosis is characterized by the onset of gastrointestinal symptoms within 24 hours; neurological symptoms occur within 48 hours. The toxicosis is particularly serious in elderly patients, and includes symptoms reminiscent of Alzheimer's disease. All fatalities to date have involved elderly patients.

 

 

"Bon Apetit"

 

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