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Meningitis and Encephalitis

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There are vaccines available for:

  • Haemophilus influenzae type b—widespread vaccination of children in the U.S. has drastically reduced the incidence of Haemophilus influenzae type b. For details, see the CDC page on Hib Vaccination.
  • Streptococcus pneumoniae (pneumococcal meningitis)—see the CDC page on Pneumococcal Vaccination.
  • Neisseria meningitidis (meningococcal meningitis)—see the CDC page on Meningococcal Vaccination.

Those with close contact to someone who has meningococcal meningitis may be prescribed antibiotics for a few days to decrease their risk of developing a full-blown infection.


Risk of infection caused by an arbovirus can be minimized by limiting exposure to mosquitoes and ticks, limiting outdoor activities at night, wearing long-sleeved clothing, using insect repellents, and eliminating freestanding water around the home.


Treatment for encephalitis, meningitis, and meningoencephalitis is targeted to the cause of the infection and inflammation while minimizing tissue damage and complications and relieving patient symptoms. Bed rest in a dark quiet room, fluids, pain relief for head and body ache, anti-inflammatory drugs, anti-seizure medications, sedatives, and anti-nausea agents may be prescribed. Corticosteroids may be given in some cases to help reduce tissue and brain swelling.

Treatment for bacterial causes
Acute bacterial and fungal meningitis and encephalitis are considered medical emergencies. Bacterial infections are frequently treated with a broad-spectrum antibiotic as soon as, or even before, the cause is positively identified. This therapy may then need to be modified once culture results identify the specific bacteria and its susceptibility to antimicrobial agents. Antibiotics chosen must be able to pass through the blood-brain barrier and reach sufficient concentration in the CSF. They may be administered intravenously and reach high levels in the blood. Patients are monitored for signs of drug toxicity and for organ function. Depending on the type of bacteria and the state of the patient's immune system, treatment may need to be continued for weeks, months, or even years.

Medical procedures are sometimes necessary to drain infected abscesses or sinuses. These procedures may need to be repeated.

Treatment for viral causes
Many cases of viral encephalitis and meningitis may be mild to moderate in severity, self-limited, and only require monitoring, rest, and relief of symptoms. People with more severe cases may require hospitalization. For viral encephalitis due to herpes or varicella-zoster viruses (the cause of chickenpox and shingles), healthcare practitioners may prescribe an antiviral drug such as acyclovir. People with HIV infections are treated with highly active antiretroviral therapy (HAART).

Treatment for fungal causes
Fungal infections are usually treated with intravenous (IV) anti-fungal drugs. Treatment may continue for an extended period of time. Patients with compromised immune systems may have to continue oral therapy indefinitely to prevent the infection from recurring.

Treatment for parasitic causes
Acute parasitic meningoencephalitis caused by the amoeba Naegleria fowleri is frequently fatal because there are no antimicrobial drugs proven effective to treat this infection. Infections with Toxoplasma and other parasitic agents may resolve with appropriate anti-parasitic drugs.

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