Meningitis

Meningitis is inflammation of the membranes that surround the brain. Meningitis can be caused by either a virus or bacteria. Bacterial meningitis may be life-threatening.

What is meningitis?

Meningitis is a disease caused by an inflammation of the meninges. These are the membranes that surround the brain and spinal cord. The inflammation is usually caused by infection of the fluid surrounding the brain and spinal cord. 

Side view of head and neck with cross section of brain showing cerebrospinal fluid around the brain and spinal cord.

What causes meningitis?

There are several types of meningitis with different causes:

Cause

Details

Viral (caused by a virus)

  • Viral meningitis is more common than bacterial meningitis. Meningitis from most viruses is rarely life-threatening. But some can cause long-standing nervous system complications or death. Viral meningitis can be caused by different viruses. It is spread between people by coughing or sneezing, or through poor hygiene. Rarely, insects, such as mosquitoes and ticks, may spread these viruses.

  • In a few cases, viral meningitis can be helped by special antiviral medicines that target specific viruses. Most people have a full recovery. But headaches, fatigue, and depression may continue.

Bacterial (caused by a bacterium)

  • Bacterial meningitis, although rare, may be fatal.

  • Bacteria may be spread through respiratory and throat fluids. This can be through coughing and kissing.

  • Many species of bacteria can cause meningitis. Below are 4 types: 

    • Neisseria meningitidis (meningococcus). This is a common cause of bacterial meningitis in children 2 to 18 years of age. It is spread by respiratory droplets and close contact. Meningococcal meningitis occurs most often in the first year of life. But it may also occur in people who live in close quarters, such as a college dorm.

    • Streptococcus pneumoniae (pneumococcus). This is the most common and most serious form of bacterial meningitis. People with weak immune systems are most at risk.

    • Haemophilus influenzae type b. The Hib vaccine has greatly decreased the number of cases in the U.S. Children who don't have access to the vaccine and those in daycare centers are at higher risk of getting this illness.

    • Listeria monocytogenes. This has become a more frequent cause of meningitis in newborns, pregnant women, people older than age 60, and in people of all ages who have a weak immune system.

Fungal meningitis (caused by a fungus)

  • Fungal meningitis is very uncommon. It can happen in people with a weak immune system. This might be from AIDS or cancer.

  • Fungal infections can rarely be caused by medical procedures. This can happen if there is contamination.

Aseptic meningitis

  • Aseptic meningitis can occur when there is inflammation of the meninges from an immune response, but no evidence of a bacterial infection. It is most often due to certain viruses.

  • Autoimmune disorders and certain medicines can cause inflammation without an infection.

Carcinomatous meningitis

  • Sometimes meningitis can be caused by cancer cells in the spinal fluid.

What are the symptoms of meningitis?

These are the most common symptoms of meningitis:

  • Fever

  • Headache

  • Nausea and vomiting

  • Stiff neck

  • Sensitivity to bright light

  • Confusion

  • Joint aches or pains

  • Drowsiness

  • Seizures

Symptoms for children may include:

  • Fever

  • High-pitched cry

  • Pale, blotchy skin color

  • Not wanting to eat

  • Vomiting

  • Fretful and fussy

  • Arching back

  • Difficult to wake

These symptoms may not occur all at once. And not everyone who gets meningitis will have all of these symptoms. The symptoms of meningitis may look like other health problems. Always see your healthcare provider for a diagnosis.

How is meningitis diagnosed?

Along with a health history and physical exam, your healthcare provider may do one or more of the following tests: 

  • Spinal tap (lumbar puncture). The healthcare provider puts a needle into the lower back and into the spinal canal. This is the area around the spinal cord. They measure the pressure in the spinal canal and brain. The provider may remove a small amount of cerebral spinal fluid (CSF) to test it for infection or other problems. CSF is the fluid that bathes the brain and spinal cord.

  • Blood testing. Blood is collected and tested for infection.

  • CT scan. This procedure uses X-rays and a computer to make images of the body. A CT scan shows detailed images of any part of the body. This includes the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.

  • MRI. This procedure uses a magnet to create very detailed images of the brain and spine. MRI uses no radiation but may take longer than a CT scan.

How is meningitis treated?

Treatment may include:

  • Bacterial meningitis. IV (intravenous) antibiotics are used to treat bacterial meningitis. The earlier the treatment is started, the better the outcome. Steroids can help in treating bacterial meningitis in babies and children. But this treatment is used less often in adults. Dexamethasone is a type of steroid. It may be given in certain cases of bacterial meningitis. It lowers the inflammatory response caused by the bacteria.

  • Viral meningitis. Treatment for viral meningitis is usually aimed at easing symptoms. Except for the herpes simplex virus, there are no specific medicines to treat the viruses that cause meningitis. Sometimes antiviral medicines are used to treat some other specific types of viruses.

While you are recovering from meningitis, your healthcare provider may advise other treatments to help you get better faster and ease symptoms. These may include:

  • Bed rest in a dimly lit room

  • Medicines to reduce fever and headache. Don't take aspirin.

You may need extra oxygen or a breathing machine (ventilator) if you become very ill and have trouble breathing.

Can meningitis be prevented?

Several vaccines can prevent types of bacterial meningitis. These vaccines are recommended for babies and children. Two doses between ages 11 and 18 are also recommended.

In certain cases, your healthcare provider may advise one of the meningitis vaccines. You may need a meningitis vaccine if you have:

  • Chronic lung conditions, such as emphysema or chronic obstructive pulmonary disease

  • Heart disease

  • Diabetes

  • Chronic kidney failure

  • Decreased immunity status

  • Certain blood disorders

  • Damaged or removed spleen

You may also need one if you travel to countries where meningitis is widespread. If you have questions about prevention, see your healthcare provider.

Wearing insect repellant and long pants and sleeves may also reduce the risk of certain viruses spread by mosquitoes and other insects.

Key points about meningitis

  • Meningitis is a disease caused by an inflammation of the meninges. These are the membranes that surround the brain and spinal cord.

  • It's usually caused by a virus. But it can be caused by bacteria and fungi.

  • Sometimes meningitis can be from noninfectious causes, such as autoimmune disorders or medicines.

  • Treatment for meningitis depends on the cause of the disease.

  • Vaccines can prevent or lower your chance of getting meningitis.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.

  • Before your visit, write down questions you want answered.

  • Bring someone with you to help you ask questions and remember what your provider tells you.

  • At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

  • Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

  • Ask if your condition can be treated in other ways.

  • Know why a test or procedure is recommended and what the results could mean.

  • Know what to expect if you do not take the medicine or have the test or procedure.

  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your healthcare provider if you have questions, especially after office hours or on weekends.