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

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
  • chills
  • feeling sick or vomiting
  • diarrhoea

If you have these symptoms, you can usually look after yourself at home. Read about how to treat sickness and diarrhoea yourself.

Call your midwife if you’re pregnant and think you have listeriosis

You may need a blood test to check for the infection. You’ll be given antibiotics if you have listeriosis because it could cause serious problems like a miscarriage if not treated.

Ask for an urgent GP appointment if:

  • you think you have listeriosis and you have a condition that weakens your immune system (like diabetes)
  • you think you have listeriosis and you’re having treatment that weakens your immune system (like chemotherapy)
  • you think your baby might have listeriosis

If it’s not treated, severe listeriosis can cause serious infections like meningitis in babies and people with a weak immune system.

How to avoid listeriosis

There are some simple things you can do to reduce your risk of getting listeriosis: