2.1 Why food makes people ill

Four common mistakes

Many people hold wrong ideas about food poisoning. Four facts correct the most common ones:

• Food that carries enough germs to make you sick can still look, smell and taste fine.
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• Food that is very fresh can still make people ill if it is handled badly.
• A clean kitchen can still serve unsafe food.
• Food can cause illness even after it has been cooked correctly.
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Three causes

Illness from food has three broad causes: something harmful gets into the food (a contaminant), the food is handled the wrong way, or a guest has a food allergy.

Contaminants come in three kinds:

• Chemical — for example cleaning products or pesticides.
• Physical — objects such as a hair, a bandage or a piece of glass.
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• Biological — living germs, carried in by a sick worker, a dirty work surface or unsafe water. These cause far more illness than the other two kinds.

Microbes and pathogens

• Bacteria live in many foods and in the human body. Only some kinds cause illness. Salmonella, Listeria, Campylobacter and E. coli are bacteria that do, so foods that may carry them need careful handling and proper cooking.
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• Viruses do not grow in food, but food can carry them. Usually a food handler passes the virus on through poor hygiene or bad handling. Hepatitis A and norovirus are two examples.
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• Parasites are carried by people and animals, inside or on the body. They make people ill when infected food is not cooked hot enough, or not frozen cold enough, to kill them. Trichinella in pork and some game, and roundworms in raw fish, are examples.
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• Protozoa are single-celled animals found in water. Giardia lamblia can live in rivers, lakes, streams and shallow wells. Salad greens washed in that water and served raw can pass it on.
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• Fungi grow on decaying matter. Many are harmless, but the mold on spoiled food can be harmful, and cutting or scraping off the part you can see does not remove it.
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Fast illness and slow illness

People often blame a short, sudden sickness on "the 24-hour flu". There is no such illness; many of these cases are really caused by food.

• Food intoxication happens when bacteria grow in the food and leave behind a poison, called a toxin. The poison is eaten with the food, so the guest reacts quickly. Staphylococcus works this way.
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• Food infection happens when live pathogens are eaten and then multiply inside the gut. Because they must grow first, the illness comes on more slowly. Salmonella works this way.
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Handling mistakes

The top ten handling mistakes that cause most illness from food are:

• Improper cooling
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• Advance preparation
• Infected person
• Inadequate reheating for hot holding
• Improper hot holding
• Contaminated raw food or ingredient
• Unsafe source
• Use of leftovers
• Cross-contamination
• Inadequate cooking

Allergies

A food allergy affects only certain people, but it can kill. Preventing a reaction means knowing and communicating every ingredient in a dish, including ingredients inside bought-in, ready-made products, and using separate tools, pans and surfaces.

Case Study - A guest said they were allergic to MSG and ordered chicken strips with sweet and sour sauce. The server said the kitchen did not add MSG to its food. The sauce, though, was bought ready-made, and MSG was on its label. The guest's lips tingled and they broke out in hives. A server who knew every ingredient in the dish could have prevented it.