Meningitis

  • Key facts

    • Meningitis is an infection and resulting inflammation of the meninges, the membranes that surround the brain and spinal cord.
    • Meningitis is most commonly caused by bacteria or viruses though it may also be caused by a fungal infection, a reaction to certain medications or medical treatments, an inflammatory disease such as lupus, some types of cancer, or a traumatic injury to the head or spine.
    • Knowing whether or not the infection is caused by a virus or bacteria is important because the severity of the illness and treatment differ depending on what type of meningitis an individual has.
    • Bacterial meningitis is a rare but sometimes fatal disease. Bacterial meningitis is commonly caused by three bacteria:

    Pneumococcal meningitis
    is the most common form of meningitis and the most serious form of bacterial meningitis. Six thousand cases of pneumococcal meningitis are reported in the U.S. annually. The disease is caused by the bacterium Streptococcus penumoniae which also causes pneumonia, blood poisoning, and ear and sinus infections. Children under age 2 and adults with weakened or depressed immune systems are at higher risk than others. Aftereffects include neurological problems ranging from deafness to severe brain damage.

    Meningococcal meningitis
    caused by the bacterium, Neisseria menigitides, affects about 2,600 individuals a year and is common among children ages 2 – 18. Ten to fifteen percent of cases are fatal with another 10-15 percent experiencing brain damage or other serious side effects. High risk groups include infants under age 1, people with suppressed immune systems, travelers to foreign countries where the disease is endemic, and college students, especially freshmen, who live in dormitories.

    Haemophilus meningitis
    caused by the haemophilus influenzae bacteriaum (Hib) Until introduction of Hib vaccines into routine childhood immunization programs in the 1990s, Hib disease, mainly meningitis and pneumonia in young children, was a significant public health concern in developed as well as developing countries. Since introduction of the Hib vaccines, the Hib-related meningitis has largely disappeared from the United States.

    • Viral or aseptic meningitis is the most common form of meningitis in the U.S. It is rarely fatal in individuals with a healthy immune system. It is frequently not diagnosed because it is thought to be the flu. It is usually caused by enteroviruses — viruses that enter the body through the mouth and travel to the brain and surrounding tissues. Enteroviruses are present in mucus, saliva, and feces and can be transmitted through direct contact with an infected person or infected object or surface. Individuals infected with viral meningitis usually recover without specific treatment within 7 to 10 days

    Signs and symptoms

    • Hallmark signs of meningitis are sudden fever, severe headache, and a stiff neck. In more severe cases, neurological symptoms may include nausea and vomiting, confusion and disorientation, drowsiness, sensitivity to bright light, and poor appetite.
    • Meningitis often appears with flu-like symptoms that develop over 1-2 days.
    • In newborns and infants, typical symptoms of fever, headache, and neck stiffness may be hard to detect. Other signs in babies might be inactivity, irritability, vomiting, and poor feeding.
    • Since the symptoms of viral and bacterial meningitis are often similar, persons who believe they have been exposed should seek medical help as soon as possible.

    Diagnosis

    • Early diagnosis and treatment are important. If symptoms occur, the patient should see a doctor immediately. Bacterial meningitis can be treated with a number of effective antibiotics but treatment must start early.
    • The diagnosis of bacterial meningitis is usually made by growing bacteria from a sample of spinal fluid. The spinal fluid is obtained by a spinal tap. A doctor inserts a needle into the lower back and removes some fluid from the spinal canal. Identification of the type of bacteria responsible for the meningitis is important for the selection of correct antibiotic treatment.

    Treatment

    • Viral meningitis has no specific treatment at this time. Most patients recover on their own. Physicians may recommend bed rest, plenty of fluids, and medicine to relieve fever and headache. Persons with severe viral meningitis may be hospitalized for supportive care. The physician may prescribe anticonvulsants such as dilantin or phenytoin to prevent seizures and corticosteroids to reduce brain inflammation. If inflammation is severe, pain medicine and sedatives may be prescribed to make the patient more comfortable.
    • Bacterial meningitis: strong doses of general antibiotics may be prescribed first, followed by intravenous antibiotics in more severe cases.

    Prevention

    • Good personal hygiene reduces the risk of getting the disease from an infected person. Avoid sharing food, utensils, glasses and other objects with a person who may have or been exposed to the infection.
    • Wash hands often with soap and rinse under running water.
    • People who live, work, or go to school with someone who has been diagnosed with bacterial meningitis may be asked to take antibiotics for a few days as a preventive measure.
    • Several vaccines protect against bacterial meningitis but their effectiveness varies depending on the type of bacteria.