Listeria meningitis

On this page you’ll find an overview of meningitis caused by Listeria bacteria, including symptoms, treatment and prevention.

• Listeria meningitis is a life-threatening disease that needs treatment with antibiotics. 
• It occurs mainly in babies, elderly people and those with weakened immune systems.
• There is no vaccine to protect against Listeria meningitis.
• You can lower the risk of your baby getting Listeria meningitis by avoiding eating certain foods during pregnancy.

What is Listeria meningitis?

Listeria meningitis is the swelling of the membranes, called meninges, that cover and protect the brain and spinal cord. It’s a serious complication of an infection, known as listeriosis, by a type of bacteria called Listeria monocytogenes (L. monocytogenes).

Listeria meningitis occurs when L. monocytogenes invade the body and enter the cerebrospinal fluid (CSF), which surrounds and cushions the brain and spinal cord. In the CSF, bacteria can rapidly multiply and release poisons, causing inflammation and swelling in the meninges. This increases pressure on the brain, producing symptoms of meningitis.

What are the symptoms of Listeria meningitis?

Early symptoms of Listeria meningitis can look like milder, more common infections.

Early diagnosis and treatment will increase the chances of a full recovery from Listeria meningitis.

Symptoms may include: 

• Fever.
• Vomiting.
• Severe headache.
• Stiff neck (less common in young children).
• Dislike of bright lights.
• Seizures (fits).
• Confused / delirious.
• Very sleepy / vacant /difficult to wake.

• High temperature (warning: could be normal or low in babies under three months old).
• Irritability.
• Vomiting / refusing to feed.
• A high-pitched cry.
• A stiff body with jerky movements or else floppy and lifeless.
• Very sleepy / staring expression / too sleepy to wake up.
• Tense or bulging soft spot on the top of their head.

How do you get Listeria meningitis?

Listeria meningitis is caused by exposure to the bacteria L. monocytogenes, which causes an infection known as listeriosis. In most cases, people are exposed by eating contaminated food. The bacteria can survive, and even grow under refrigerator temperatures. Vegetables can become contaminated through the soil or via the use of manure as fertilizer. Ready-to-eat foods may be contaminated with the bacteria during processing, distribution and storage.²

In pregnancy it’s recommended you avoid eating certain foods such as those containing unpasteurised milk, soft cheese, ready-to-eat cold-smoked or cured fish. These foods are at risk of being contaminated with L. monocytogenes. If you get listeriosis when you are pregnant, there’s a chance that it can be passed to the baby.

Listeriosis isn’t usually serious for most people. But in a susceptible person, the bacteria may overcome the body’s defences and travel in the blood to the meninges around their brain to cause meningitis.

Who can get Listeria meningitis?

Listeria meningitis can affect anyone. But certain groups of people are at higher risk of Listeria meningitis. This includes:

• Pregnant women, who are sixteen to eighteen times more susceptible to Listeria infection than other adults.³ If they become infected they can pass it to their unborn baby. This can cause miscarriage, stillbirth, premature birth and serious illness in the newborn baby.
• Newborn babies, who are vulnerable to infection and can ‘catch’ listeriosis in the womb or during or after birth. The infection can be classified as early-onset or late-onset, depending on how long after birth the baby starts to develop symptoms. If a baby develops symptoms at birth or within 48 hours of birth, this is known as early-onset and usually causes sepsis. If symptoms begin 48 hours after birth, this is termed late-onset infection and tends to cause meningitis.

• People aged over 60 years.
• People who have a weakened immune system due to illnesses like cancer, diabetes, kidney disease, liver disease or chronic infections.
• People who are taking immunosuppressant medication (drugs that calm or control the body’s immune system).
• People with malignancies (especially of the blood).
• People with alcohol dependency.⁴

How is Listeria meningitis treated?

Listeria meningitis needs urgent treatment with antibiotics.

Meningitis can kill quickly, so if you suspect that you have this disease you should seek immediate medical care. If the Listeria infection occurs during pregnancy, prompt treatment with antibiotics can prevent the infection being passed to the baby. Prompt recognition and hospital treatment offer the best chance of a good recovery.

When you get to hospital, the doctor may do a lumbar puncture (LP) to help diagnose meningitis. A lumbar puncture involves taking a sample of cerebrospinal fluid from the spinal canal (the space through the back bones which contains the spinal cord). A lumbar puncture is important to confirm the diagnosis of meningitis. It will also show which germ is causing the illness so doctors can choose the most appropriate treatment.

You may be given antibiotics intravenously (directly into the vein). In the UK these should be given within an hour of the doctors suspecting meningitis. Steroids may also be given to reduce swelling around the brain, but are not recommended for the treatment of young babies.

If you’re very unwell, you might be transferred to a special ward in the hospital where you can be regularly monitored by hospital staff. In the UK this is known as an Intensive Care Unit.

L. monocytogenes is resistant to a group of antibiotics known as the cephalosporins which are commonly used to treat bacterial meningitis. In the UK, when the cause of meningitis is unknown, it is recommended that people at high risk of developing Listeria meningitis are treated with a penicillin type antibiotic, such as Amoxycillin, as well as a cephalosporin.

What are the after-effects of Listeria meningitis?

Listeria meningitis affects everyone differently. Most people make a full recovery without any lasting problems. But in some cases, it can cause ongoing problems which may need further treatment and support.

The possible after-effects of Listeria meningitis include:

• Learning and intellectual disabilities such as memory loss, lack of concentration or issues with thinking and problem solving.
• Clumsiness and co-ordination problems.
• Headaches.
• Deafness, hearing problems, tinnitus, dizziness or loss of balance.
• Epilepsy or seizures.
• Weakness, paralysis or spasms.
• Loss of sight or vision problems.
• Hydrocephalus (fluid on the brain).
• Mental health issues and changes to personality or behaviour.
• Difficulties with sleep.
• Fatigue.
• Anxiety and depression.

Long-term after-effects of meningitis are usually identified while you are still in hospital. For very young babies it might not be possible to tell if they have any long-term effects until they get older. 

Is there any follow-up care after recovery from Listeria meningitis?

Ideally, you should be given information about what to expect during recovery before you leave the hospital. The follow-up care you receive will be different depending on where in the world you live, the services available, and the guidelines that your local doctors follow. If your baby has ongoing needs, they might have further treatment involving different teams of doctors and specialists.

In the UK, doctors will arrange at least one follow up appointment six weeks after the initial illness so they can check for longer-term after-effects.⁵ For babies under one year of age, there will be an additional follow-up appointment one year after the illness. This is particularly important as some long-term neurodevelopmental after-effects can't be identified immediately after your baby’s initial illness.

Read more about the follow-up care after recovery from meningitis.

Can we prevent Listeria meningitis?

It isn’t always possible to prevent Listeria meningitis. But as almost all cases of listeriosis are caused by eating contaminated food, there are some things you can do to help prevent getting it. This is especially important during pregnancy. You can:

• Avoid eating high-risk foods such as:
  –unpasteurised milk or dairy products
  –some soft cheeses (brie and camembert)
  –pre-prepared fruit or vegetables
  –smoked seafood
  –ready-to-eat seafood and cold meats (especially deli meats), unless cooked at a high temperature before eating.
• Avoid eating food that has passed its ‘use by’ date.
• Eat freshly prepared food.
• Cook food thoroughly or reheat until steaming.
• Use good food hygiene, such as washing your hands regularly with soap and water.

Can I get a vaccine to protect me against Listeria meningitis?

There are no vaccines available that prevent Listeria infection.