Listeria is an illness caused by eating foods contaminated by the bacteria, Listeria monocytogenes. Listeria infection is uncommon but it can cause death in at-risk people, such as the elderly and people whose immune systems are not working properly. It can be dangerous to pregnant women and their unborn babies.
Some foods are high risk
Some foods are more likely to contain listeria. These include:
- Ready-to-eat seafood, such as smoked fish or mussels
- Premixed raw vegetables, including coleslaw
- Precooked meats, such as pate, deli meat and cooked chicken used in sandwich shops
- Unpasteurised milk
- Soft-serve icecreams
- Soft cheeses like brie, camembert and ricotta.
Symptoms range from mild to severe
Early symptoms include:
- Aches and pain.
These can lead to more serious problems, including:
- Meningitis (brain infection)
- Septicaemia (blood poisoning).
It’s dangerous for pregnant women
Even a mild infection can cause:
- Premature birth
- A baby who is very ill when born.
Other people who are at high risk
People at high risk include:
- The elderly.
- People whose immune system is weakened by illnesses like cancer, liver or kidney disease and diabetes.
- People on medications like prednisolone or cortisone. This includes organ transplant patients.
Listeria can be treated with antibiotics but prevention is best
Early use of antibiotics can help, but prevention is best. At-risk people should:
- Only eat freshly prepared foods
- Avoid high risk foods
- Avoid dips and salad dressings
- Avoid ready-to-eat foods kept in the fridge for more than one day.
Some hints when handling and preparing food
When you handle and prepare food, you should take care to:
- Wash your hands before preparing food, and between handling raw food and ready-to-eat foods.
- Wash raw fruit and vegetables well before eating.
- Cook all foods of animal origin, including eggs, thoroughly.
- Don't use the same boards, knives etc for cooked foods that you used for raw foods, unless they have been washed in warm, soapy water.
- Defrost food by placing it on the lower shelves of the fridge or use a microwave.
Store food with care
When you store food, you should:
- Keep food covered.
- Place cooked food in the fridge within one hour of cooking.
- Put raw meat, poultry and fish below cooked or ready-to-eat food in the fridge to prevent drips that could contaminate preprepared food.
- Do not use refrigerated foods beyond their use-by dates.
- Keep your fridge clean.
- Your fridge temperature should be below 5°C
- Keep hot foods hot (above 60°C) and cold foods cold (at or below 5°C)
- Reheat food until the internal temperature of the food is piping hot
- Ensure microwaved food reaches an even temperature before eating.