Food poisoning

Food poisoning is illness caused by eating unsafe food. Common symptoms are vomiting, diarrhoea, stomach pain and fever. Symptoms can start within hours or can take days. For young children, older people, pregnant people and those already unwell, food poisoning can be very serious.

The bacteria that cause food poisoning do not usually change how food looks, smells or tastes. This is different from the bacteria and moulds that make food go off. Food can be dangerous and still seem perfectly good.

Norovirus is the most common cause of gastroenteritis in the UK. It is a virus, so it does not need to grow in food. It spreads from infected people, through hands, surfaces and food. One infected food handler can pass it to many customers.

Campylobacter is the most common bacterial cause of food poisoning. It is found on raw poultry. Even one drop of raw chicken juice can be enough to make someone ill.

Salmonella is linked to raw eggs, poultry and meat. Thorough cooking kills it. Keep raw eggs away from ready-to-eat food, and wash your hands after handling them. E. coli O157 is linked to raw and undercooked beef, especially mince, and to soil on vegetables. A very small amount can cause serious illness, including kidney failure.

Listeria monocytogenes can grow at chill temperatures, so a fridge will not stop it. The risk comes from ready-to-eat chilled food, such as pâté, soft cheese, smoked fish and sliced cooked meats. It is especially dangerous in pregnancy. This is one reason why use-by dates matter so much.

Staphylococcus aureus lives on skin, in noses and in infected cuts. It passes to food from hands, and makes a poison in the food.

Bacillus cereus is linked to cooked rice. Clostridium perfringens is linked to large meat dishes that are cooled slowly. The next lesson explains why.

If a customer says your food made them ill, tell your manager straight away. Write down what they ate and when. Keep aside any of that food you still have, and do not throw it away. Do not argue with the customer. A business that believes it has sold unsafe food must tell the authorities.