What is viral meningitis?

On this page you’ll find an overview of meningitis caused by viruses, including transmission, symptoms, treatment and after-effects.

• Viral meningitis is rarely life-threatening.
• Viruses are the most common cause of meningitis globally.

What is viral meningitis?

Viral meningitis is the swelling of the lining of the brain and spinal cord (called meninges) caused by a viral infection. If a virus enters the cerebrospinal fluid (CSF), which surrounds and cushions the brain and spinal cord, it can cause inflammation and swelling in the meninges. This increases pressure on the brain and results in the symptoms of meningitis.

You can feel very unwell if you have viral meningitis, but it's rarely life-threatening. Most people make a good recovery. 

The viruses that cause meningitis can also cause encephalitis, which is swelling of the brain tissue.  Encephalitis is life-threatening and requires urgent treatment.

What are the symptoms of viral meningitis?

The symptoms of viral meningitis can be similar to bacterial meningitis. It’s important to seek urgent medical help if you suspect a case of meningitis.

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

Symptoms may include:

• Fever.
• Vomiting.
• Severe headache.
• Stiff neck.
• Dislike of bright lights.

Symptoms in babies and very young children can be slightly different. Their symptoms may include:

• High temperature (warning: could be normal or low in babies under three months old).
• Irritability.
• Vomiting / refusing to feed.
• A high-pitched cry.

• Tense or bulging soft spot on the top of their head.

Not everyone with meningitis will get all these symptoms.

The symptoms of bacterial and viral meningitis can be similar, and it’s not possible to know what is causing the illness without further testing. People with bacterial meningitis will get worse fast and need urgent treatment with antibiotics, while meningitis caused by a virus is generally much less dangerous.

Check regularly on someone who is unwell. Always trust your instincts and get professional medical help immediately if you or someone you know is seriously ill.

Learn more about the symptoms of meningitis

How do you get viral meningitis?

The viruses that cause meningitis are very common and usually cause only mild cold and flu-like symptoms. Getting meningitis after becoming infected with a virus is rare.

Many different types of virus can cause meningitis. Some of the more common ones are:

• Enteroviruses (responsible for around 90% of all viral meningitis cases).
• Parechoviruses (an important cause of viral meningitis in young babies).
• Herpes viruses (also the cause of chickenpox, shingles, cold sores and genital warts).
• Mumps virus.
• Measles virus.
• Arboviruses (includes West Nile virus, Japanese encephalitis, tick-borne encephalitis and dengue).
• Human immunodeficiency virus (HIV).
• Lymphocytic Choriomeningitis (LCM).

Remember that getting meningitis after becoming infected with these viruses is rare.

Viral meningitis is not contagious. It’s possible for people with some types of viral meningitis to pass the virus to others, but it would be very unlikely to lead to another case of viral meningitis.

How is viral meningitis treated?

There are no treatments for most viruses that cause meningitis, as antibiotics won't be effective. So, treatment is normally limited to easing the symptoms, such as painkillers for headache or anti-emetics to stop vomiting.

Most people recover within five days to a fortnight, but for some the recovery period is longer.

When you are in the hospital with meningitis, the doctor may do a lumbar puncture. This is when a sample of cerebrospinal fluid (CSF) is taken from your spinal canal (the space through the back bones which contains the spinal cord). The sample of CSF is examined and sent for further laboratory testing. A lumbar puncture is important to confirm the diagnosis of meningitis, and to show which germ is causing the illness

What are the after-effects of viral meningitis?

Viral 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 following after-effects can be a concern for at least the first year of recovery from the illness:^1,2,3,4

• Learning and intellectual disabilities such as memory loss, lack of concentration or issues with thinking and problem solving.
• Headaches.
• Difficulties with sleep.
• Fatigue.
• Anxiety and depression.

Some children who have enteroviral meningitis and are under one year old have been shown to develop subtle neurological problems later in life.⁵ A small proportion (less than 1%) of young infants with viral meningitis may be left with serious neurological after-effects, such as seizures in the first year after the illness.⁶

The viruses that cause meningitis can also cause encephalitis, which is swelling of the brain tissue. This condition is more serious than viral meningitis. People with encephalitis are more likely to be left with long term after-effects. Support and information about recovery from encephalitis is available from the Encephalitis Society website.

Can we prevent viral meningitis?

Most causes of viral meningitis are not preventable. A good general precaution against viral meningitis is attention to handwashing. The most common cause of viral meningitis, enteroviruses, usually enter the body via the hand-to-mouth route.

There are vaccines available against some causes of viral meningitis. Immunisation against mumps, measles and rubella (MMR) is offered in many countries globally. Some countries also routinely immunise against varicella zoster virus (a herpes virus that can cause meningitis but much more commonly causes chickenpox). You can check immunisation schedules for your own country on the World Health Organisation website.

Immunisations are also available for some arboviruses such as tick-borne encephalitis and Japanese encephalitis. Vaccinations may be recommended for travellers to areas where the risk of these infections is high.

Author: Meningitis Research Foundation.
Reviewed by: Ian Alexander, Meningitis Research Foundation Ambassador; Hajime Takeuchi, the Japan Child Meningitis Organisation and CoMO member.
Published: 23 December 2024.