Most cases of illness from food do not happen because the food is "off". The food often looks, smells and tastes normal. The danger is the microorganisms in it that we cannot see.
Foodborne illness
These are called foodborne infections (alimentární nákazy) and food poisoning. Typical symptoms are diarrhoea, vomiting, stomach pain and fever. Sometimes they appear within a few hours, sometimes only after several days. In children, older people, pregnant women and people who are ill they can be serious.
The most common causes
- Salmonella. Found in raw poultry meat, in eggs and in dishes made with raw eggs.
- Campylobacter. Mainly raw poultry. Transfer to hands or a chopping board is enough.
- Escherichia coli (some strains), for example from undercooked minced meat and raw vegetables.
- Listeria monocytogenes. Grows even in the fridge. Pregnant women, newborns and people with weakened immunity are most at risk.
- Staphylococcus aureus. Lives on the skin, in the nose and in festering wounds. In prepared food it produces a toxin that boiling does not destroy.
- Clostridium perfringens and Bacillus cereus. They survive as spores and multiply in food left at room temperature for a long time after cooking.
- Norovirus and the hepatitis A virus. Spread mainly by the dirty hands of a sick person. A small amount is enough. Norovirus does not multiply in food, it is only carried by it.
- Parasites (for example in undercooked meat or fish).
How microorganisms multiply
Bacteria divide. In favourable conditions one becomes millions within a few hours. They need:
- nutrients: meat, milk, eggs, cooked rice and pasta suit them best;
- moisture: they multiply little in dry foods;
- warmth: they grow fastest at the temperatures at which people eat and live;
- time: every extra hour in the warm is a risk.
The defence is cold, thorough cooking and speed. Cold only slows bacteria down. Cooking destroys most of them, but the spores and toxins of some survive.
How bacteria get into food
- from raw materials (raw meat, eggs, unwashed vegetables),
- from people (hands, coughing, wounds, carriers who have no symptoms),
- from surfaces and utensils (chopping boards, knives, cloths),
- from water, pests and waste.
A person can spread an infection even when they have no symptoms themselves. That is why one rule applies to everyone: clean hands, clean utensils, the right temperature.
A sick worker
The rule is in Regulation (EC) No 852/2004, Annex II, Chapter VIII:
- Anyone suffering from or being a carrier of a disease likely to be transmitted through food must not handle food or enter areas where food is handled if there is any likelihood of direct or indirect contamination.
- The same applies to infected wounds, skin infections, sores and diarrhoea.
- Anyone so affected who may come into contact with food must report the illness or its symptoms immediately to the operator, and if possible their cause.
What this means in practice:
- If you have vomiting or diarrhoea, do not come to work and tell your supervisor.
- Do not work with food until the symptoms have passed and your doctor or employer has decided you can.
- If the illness starts at work, leave the food immediately.
- Good practice: also tell your supervisor if someone in your household is ill at home with diarrhoea or vomiting.
The employer must not let a sick person work in the food area. Reporting an illness is not a failure. It protects customers and colleagues.