Listeria is a foodborne bacterial illness which can make you sick. Infection with listeria bacteria is called listeriosis.

Listeriosis is particularly dangerous for pregnant women. It can cause miscarriage, premature labour or stillbirth, and can cause infection in their baby.

Listeria is a common bacterium (bug) widely found in dust, soil, water, plants, sewage and animal droppings. It can be transmitted through infected food.

It usually causes few or no symptoms, but can be serious for pregnant women, newborn babies, older people, and people with weakened immune systems.

If a pregnant woman develops an infection caused by listeria (listeriosis), it can cause miscarriage and stillbirth. Newborn babies who develop listeriosis can have difficulty breathing, develop a chest infection, and inflammation of the coverings of the brain (meningitis). This can sometimes cause death.

Pregnant women and others at risk should not eat foods most likely to contain listeria, including unpasteurised milk and cheese, some seafood and processed meats such as luncheon meat and salami.

If you are concerned about listeria, call Healthline on 0800 611 116 or see your doctor or practice nurse.

Listeria can be spread through eating infected food. The bug has been found in a variety of foods at all stages of preparation, from raw to well-cooked left-overs. Listeria will still grow on food that is stored in a fridge.

It can also be passed from mother to baby during pregnancy or birth.

If you’ve eaten contaminated food, it can be a few days before you feel unwell.  

Symptoms include:

  • mild fever
  • headache
  • aches and pains
  • feeling sick or nauseous
  • vomiting or diarrhoea
  • stomach cramps.

Some people get very sick with listeriosis. 


To reduce the risk of listeriosis

Pregnant women and others at risk should not eat foods most likely to contain listeria, including:

  • raw (unpasteurised) milk and cheese, and any food that contains unpasteurised milk
  • soft, semi-soft or surface-ripened soft cheese (eg, brie, camembert, feta, ricotta, roquefort)
  • processed meats including ham and all other chilled pre-cooked meat products including chicken, salami and other fermented or dried sausages
  • cold pre-cooked chicken
  • uncooked, smoked or ready-to-eat fish or seafood, including oysters, prawns, smoked ready-to-eat fish, sashimi or sushi
  • paté, hummus and tahini-based dips and spreads
  • pre-prepared, pre-packaged or stored salads (including fruit salads) and coleslaws
  • soft-serve ice creams.

To treat listeriosis

Most people with mild symptoms of listeriosis require no treatment. More serious infections can be treated with antibiotics. During pregnancy, prompt antibiotic treatment may help keep the infection from affecting the baby.

Stay away from school, early childhood centres or work until two days after the symptoms have gone, and don’t have visitors from outside the family.

Listeriosis is a notifiable disease. This means that health professionals or laboratories will inform us when someone has it. This allows us to monitor the number of people who have the disease and give health professionals advice on how to reduce its spread. 


There are specific requirements for notifiable diseases in the Auckland region.

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Last updated 29.11.2018

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