What Is Meningitis?

Meningitis is a rare infection that affects the delicate membranes -- called meninges -- that cover the brain and spinal cord. You or your children can catch it.

meningitis

Types of Meningitis

Bacterial meningitis

It's an extremely serious illness. You or your child will need to get medical help right away. It can be life-threatening or lead to brain damage unless you get quick treatment.

Several kinds of bacteria can cause bacterial meningitis. The most common ones in the U.S. are:

  • Streptococcus pneumoniae (pneumococcus)
  • Neisseria meningitidis (meningococcus)
  • Listeria monocytogenes (in older people, pregnant women, or those with immune system problems)

A bacteria called Haemophilus influenzae type b (Hib) was a common cause of meningitis in babies and young children until the Hib vaccine became available for infants. There are also vaccines for Neisseria meningitidis and Streptococcus pneumoniae. Experts recommend that all children get them, as well as all adults who are at a higher risk for the disease.

In many cases, bacterial meningitis starts when bacteria get into your bloodstream from your sinuses, ears, or throat. The bacteria travel through your bloodstream to your brain.

The bacteria that cause meningitis can spread when people who are infected cough or sneeze. If you or your child has been around someone who has bacterial meningitis, ask your doctor what steps you should take to avoid catching it.

Viral meningitis

Viral meningitis is more common than the bacterial form and generally -- but not always -- less serious. A number of viruses can trigger the disease, including several that can cause diarrhea.

Fungal meningitis

Fungal meningitis is much less common than the bacterial or viral forms. Healthy people rarely get it. You’re more likely to get this form of meningitis if you have a problem with your immune system, like AIDS.

Parasitic meningitis

Parasitic meningitis is also rare. It’s caused by parasites that usually affect animals. You can get it from eating animals like snails, slugs, snakes, fish, or poultry that are infected by parasites or their eggs, or produce that contains parasite eggs. The risk is higher with raw or undercooked foods. You can’t pass on this type of meningitis to other people.

Amoebic meningitis

Amoebic meningitis is a rare, usually fatal infection by a single-celled bug called Naegleria fowleri. This amoeba lives in soil or warm, fresh water, but not salt water. People typically get it from swimming in water where the amoeba lives, not drinking it. Amoebic meningitis isn’t contagious.

Non-infectious meningitis

Non-infectious meningitis is caused by diseases like lupus or cancer, or if you’ve had a head injury, brain surgery, or take certain medications. It isn’t contagious.

Chronic meningitis

Chronic meningitis has similar symptoms as acute meningitis, but develops over a couple of weeks. It results from infections with a fungus or the mycobacteria that cause tuberculosis. These organisms get into the tissue and fluid surrounding your brain to cause meningitis.

Meningitis Symptoms

Meningitis symptoms can develop within hours or days and may include:

  • Confusion
  • Fever
  • Headache
  • Numbness in your face
  • Sensitivity to light
  • Stiff neck so that you can’t lower your chin to your chest
  • Upset stomach or vomiting
  • Severe headache with nausea or vomiting
  • A hard time concentrating
  • Seizures
  • Sleepiness or a hard time waking up
  • Lack of appetite
  • Lack of thirst
  • Skin rash (with meningococcal meningitis)

Symptoms of meningitis in infants

In infants, meningitis symptoms may include:

  • High fever
  • Crying that’s constant and gets louder when you hold the baby
  • Baby seems overly sleepy, sluggish, or inactive
  • Stiff neck or body
  • Bulge on the soft area on the top of the baby’s head
  • Poor ability to feed
  • Crankiness

Risk Factors for Meningitis

Anyone can get meningitis, but research shows that it's more common in these age groups:

  • Children under 5
  • Teenagers and young adults ages 16-25
  • Adults over 55

Meningitis is more of a danger for people with certain medical conditions, such as a damaged or missing spleen, long-term disease, or immune system disorders.

Because certain germs that cause meningitis can spread easily, outbreaks are most likely to happen in places where people live close to each other. College students in dorms or military recruits in barracks can be more likely to catch the disease. So are people who travel to areas where meningitis is more common, such as parts of Africa

Causes of Meningitis

Meningitis almost always results from a bacterial or viral infection that begins somewhere else in your body, like your ears, sinuses, or throat.

Less common causes of meningitis include:

  • Autoimmune disorders
  • Cancer medications
  • Syphilis
  • Tuberculosis

Meningitis Diagnosis

Your doctor will ask about your medical history and do a physical exam, including checking your neck for stiffness and looking for a skin rash that might suggest a bacterial infection. They will also need to do tests that can include:

  • Blood tests to find bacteria
  • CT or MRI scans of your head to find swelling or inflammation
  • Spinal tap, in which a health care worker uses a needle to take fluid from around your spinal cord. It can tell what’s causing your meningitis.

Treatment for Meningitis

Your treatment will depend on the type of meningitis you have.

Bacterial meningitis needs treatment with antibiotics right away. The doctor might give you a general, or broad-spectrum, antibiotic even before they’ve found the exact bacteria that caused your illness. Once they do, they’ll change to a drug that targets the specific bacteria they find. You might also get corticosteroids to ease inflammation.

Viral meningitis usually goes away on its own without treatment. Your doctor might tell you to stay in bed, drink plenty of fluids, and take over-the-counter pain medicines if you have a fever or aches. If a virus like herpes or influenza caused your illness, you might take antiviral medication.

Antifungal medications can treat fungal meningitis.

Complications of Meningitis

Meningitis can cause severe complications in adults and children, especially if you delay treatment. Possible complications include:

  • Seizures
  • Brain damage
  • Loss of hearing
  • Memory problems
  • Learning problems
  • A hard time walking
  • Kidney failure
  • Shock
  • Death

Prevention of Meningitis

You may be able to prevent meningitis by avoiding infection with the viruses or bacteria that cause it. These infections are passed to others when you cough, sneeze, kiss, or share toothbrushes or eating utensils. Take these steps to prevent infections:

  • Wash hands often. Rinse well. Teach your kids to wash their hands often too, especially after eating, using the toilet, or when you’re in public places.
  • Don’t share items like toothbrushes, eating utensils, or lipstick.
  • Don’t share foods or drinks with other people.
  • Cover your mouth and nose when you cough or sneeze.
  • Stay healthy. Eat a healthy diet, get plenty of exercise, and rest at night.
  • If you’re pregnant, eat food that’s well-cooked. Avoid foods made from unpasteurized milk.
  • Get immunized. Follow your doctor’s advice on getting immunization shots for diseases that may cause bacterial meningitis, including flu and pneumonia vaccines.

WebMD Medical Reference

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