Listeriosis is a rare infection caused by bacteria called listeria. It usually goes away on its own, but can cause serious problems if you're pregnant or have a weak immune system.
How you catch listeriosis
Listeriosis is usually caught from eating food containing listeria bacteria.
You can get it from lots of types of food, but it's mainly a problem with:
- unpasteurised milk
- dairy products made from unpasteurised milk
- soft cheeses, like camembert and brie
- chilled ready-to-eat foods, like prepacked sandwiches, pâté and deli meats
These foods do not always cause listeriosis. If you have eaten them recently, you do not need to do anything unless you get symptoms of the infection.
You can also catch listeriosis from:
- someone else who has it – for example, if you eat food they have handled when they have not washed their hands
- close contact with farm animals – especially sheep and cows that are giving birth
Symptoms of listeriosis
In most people, listeriosis has no symptoms or only causes mild symptoms for a few days, such as:
- a high temperature of 38C or above
- aches and pains
- feeling sick or vomiting
If you have these symptoms, you can usually look after yourself at home.
Get advice from a medical professional now if:
- you're pregnant and think you have listeriosis
- you have a condition that weakens your immune system (like diabetes) and think you have listeriosis
- you're having treatment that weakens your immune system (like chemotherapy) and think you have listeriosis
- you think your baby might have listeriosis
You may need a blood test to check for the infection and antibiotics to treat it.
Call your local emergency service if you get:
- a severe headache and stiff neck
- discomfort when looking at bright lights
- fits (seizures)
- sudden confusion
- a rash that does not fade when a glass is rolled over it – the rash may be blotchy, like bruises or small red pinpricks
These could be symptoms of meningitis caused by listeriosis, which needs to be treated in hospital straight away.
How to avoid listeriosis
There are some simple things you can do to reduce your risk of getting listeriosis:
- wash your hands regularly with soap and water
- wash fruit and vegetables before eating them
- store ready-to-eat foods as recommended by the manufacturer
- make sure all hot food is steaming hot all the way through
- do not eat food after its use-by date, even if it looks and smells normal
Foods to avoid if you're pregnant
If you're pregnant, you should avoid eating foods that have the highest risk of causing listeriosis.
- some uncooked soft cheeses – including brie and camembert
- all types of pâté – including vegetable pâté
- unpasteurised milk or dairy products
- any undercooked food
If you're pregnant, you should also avoid close contact with farm animals that are giving birth or have recently given birth.