Meningitis is an inflammation of the meninges, the membranes that surround the brain. There are three meninges:
- dura mater - the outside membrane that adheres to the inside of the skull
- arachnoid - the middle membrane
- pia mater - the innermost membrane, which adheres to the brain
There are two distinct types of meningitis:
|viral - caused by a virus
- Viral meningitis is more common than bacterial, although rarely life threatening. Viral meningitis can be caused by different viruses, and is spread between people by coughing or sneezing, or through poor hygiene. Other germs can be found in sewage polluted water.
- Viral meningitis cannot be helped by antibiotics. Recovery is normally complete, but headaches, tiredness, and depression may persist.
|bacterial - caused by a bacterium
- Bacterial meningitis, although rare, may be fatal.
- Bacteria may be spread through the exchange of respiratory and throat secretions, such as coughing and kissing, but they cannot live outside the body for long. They cannot be picked up from water supplies, swimming pools, buildings, etc.
- Many species of bacteria can cause meningitis, but four types account for most cases:
- Neisseria meningitidis (meningococcus)
Meningococcus is found in the nasopharynx of about 10 percent of the population and is spread by respiratory droplets and close contact. For unknown reasons, only a small fraction of carriers develop meningitis. Meningococcal meningitis occurs most often in the first year of life, but may also occur in closed populations, such as schools.
- streptococcus pneumoniae (pneumococcus)
Pneumococcus is the most common cause of adult meningitis. Those at high risk may include persons with chronic ear infections, sinus infections, closed head injury, recurrent meningitis, and pneumococcal pneumonia.
- group B streptococcus
Group B streptococcus is becoming a more frequent cause of meningitis in persons over the age of 50, particularly when underlying conditions or diseases are present. It is also responsible for meningitis in neonates.
- Listeria monocytogenes
Listeria monocytogenes has become a more frequent cause of meningitis in neonates, pregnant women, persons over the age of 60, and in persons of all ages who are immunocompromised.
There are several ways that the infection can reach the brain, including:
- through the bloodstream from another infected part of the body
- through the bones of the skull from infected sinuses or inner ears
- from a head injury, such as a fractured skull or penetrating wound
- after surgery or extended hospitalization
- a weakened immune system
- as a result of chronic kidney failure
Overseas travelers should check to see if meningococcal vaccine is recommended for their destination, as some countries have large epidemics of meningococcal meningitis.
Travelers should receive the vaccine at least one week before departure.
The following are the most common symptoms of meningitis. However, each individual may experience symptoms differently. Symptoms may include:
- nausea and vomiting
- stiff neck
- photophobia (low tolerance to bright light)
- joint aches or pains
- loss of appetite
Symptoms for children may also include:
- high pitched cry
- pale, blotchy skin color
- not wanting to eat
- fretful and fussy
- arching back
- difficult to wake
It is important to note that these symptoms may not occur all at once, nor in everyone who contracts meningitis. The symptoms of meningitis may resemble other conditions or medical problems. Consult a physician for diagnosis.
Early diagnosis is important so that appropriate treatment can be started immediately. The diagnosis of meningitis is usually made by taking a sample of spinal fluid obtained by performing a spinal tap. The sample of spinal fluid is analyzed in the laboratory and the type of bacteria is identified.
There are many forms and degrees of meningitis. Treating it depends on the type of bacterium or virus that causes the infection.
Specific treatment will be determined by your physician based on:
- your overall health and medical history
- extent of the disease
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
Generally, antibiotics are used to treat bacterial meningitis, and may also be prescribed for immediate family members or others who are in very close contact with the patient. Because antibiotics work by breaking the bacteria into fragments that may cause inflammation, a corticosteroid, or steroid, such as dexamethasone, may be given for bacterial meningitis in adults. The steroid works by decreasing the inflammation and reducing pressure that can build up in the brain. Antibiotics are not used for viral meningitis.
The Centers for Disease Control and Prevention (CDC) currently recommends the meningococcal vaccine for children 11 to 12 years of age and other adolescents who want to reduce their risk. Immunization for the bacteria is not widespread due to its uncommon occurrence. Individuals who may require immunization include the following:
- asplenic children - children without a spleen
- teens entering high school
- college students - immunization of college students is recommended by the American College Health Association
- military recruits
- individuals who are traveling to countries where the incidence of meningococcal infectious is higher (parts of Africa)
- family members or those in close contact of individuals with meningitis, if the individual has the following type of bacterial meningitis:
- H. influenzae type b
- Neisseria meningitis (meningococcal)
If you have questions regarding prevention, discuss this with your physician.
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