Encephalitis and Meningitis

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Encephalitis and meningitis facts

  • Encephalitis is inflammation of the brain.
  • Meningitis is inflammation of the membranes (called meninges) that surround the brain and spinal cord.
  • Both encephalitis and meningitis can be caused by bacteria or viruses, and rarely a fungus, or be noninfectious.
  • Headache and fever are the most common symptoms of encephalitis and meningitis. Stiff neck, confusion, or lethargy can also be present.
  • The diagnosis is usually made by performing a lumbar puncture (spinal tap).
  • A CT scan or MRI of the brain can also be helpful but usually is only done in addition to the spinal tap.
  • Treatment depends on identifying the underlying cause. If bacteria are causing the infection, then antibiotics are indicated.
  • Anyone experiencing symptoms of encephalitis or meningitis should see a doctor immediately.
  • Depending on the organism causing the infection, close contacts can also get sick and need to be evaluated by a health-care professional.
  • Basic methods that help to prevent the spread of infections (hand washing and covering ones mouth when coughing) can also help prevent the spread of some forms of meningitis.
  • Being up to date on vaccinations will help prevent certain forms of meningitis.

What is encephalitis?

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Encephalitis is brain inflammation.

What causes encephalitis?

Encephalitis is a rare condition that is most often caused by viruses. It can also be caused by noninfectious diseases, such as systemic lupus erythematosus and Behçet's disease. The leading cause of severe encephalitis is the herpes simplex virus. Other causes include enterovirus infections or mosquito-borne viruses. The very young and the elderly are more likely to have more severe encephalitis.

Exposure to viruses can occur through breathing in respiratory droplets from infected people, certain insect bites, and direct skin contact.

Medically Reviewed by a Doctor on 7/16/2015

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Meningitis Incubation Period

The incubation period for bacterial meningitis, the most serious types of meningitis, is about three to five days after initial contact with the microbe. However, in some individuals, bacterial meningitis symptoms can occur as rapidly as 24 hours. For viral meningitis, the incubation period can range widely from only a few days to a few weeks.