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. On average, symptoms appear after about 3 weeks but may appear as late as 2 months after you have eaten something with listeria.
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).
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, cold precooked chicken, pre- packaged or stored salads ,soft-service creams, and some dips and spreads.
If you think you have eaten food contaminated with listeria or if you have any of the symptoms of listeria infection, contact your doctor or midwife right away. Remember that it can take 2 months for symptoms to appear.
If you are concerned about listeria, call Healthline on 0800 611 116 or contact your doctor or practice nurse.
The information on this page focusses on disease prevention and protection only. Please use the ‘Resources’ and ‘Related Websites’ links below for more information.
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 or weeks before you feel unwell.
Some people get very sick with listeriosis.
If you are pregnant
If you think you have eaten food contaminated with listeria or if you have any of the symptoms of listeria infection, contact your doctor or midwife right away.
To reduce the risk of listeriosis
Pregnant women and others at risk should not eat foods most likely to contain listeria, including:
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
Last updated 11.8.2020