Meningitis

What is bacterial meningitis?

Meningitis is an infection of the fluid in the spinal cord and the fluid that surrounds the brain. Meningitis is usually caused by an infection with a virus or a bacterium. Knowing whether meningitis is caused by a virus or a bacterium is important because of differences in the seriousness of the illness and the treatment needed.

VIRAL MENINGITIS is usually relatively mild. It clears up within a week or two without specific treatment. Viral meningitis is also called aseptic meningitis.

BACTERIAL MENINGITIS is much more serious. It can cause severe disease that can result in brain damage and even death.

What bacteria cause bacterial meningitis?

Bacterial meningitis is most commonly caused by one of three types of bacteria: Haemophilus influenzae type b (Hib), Neisseria meningitidis, and Streptococcus pneumoniae.

It is important to know which type of bacteria is causing the bacterial meningitis because antibiotics can prevent some types from spreading and infecting other people.

Where is bacterial meningitis found?

Bacterial meningitis is found worldwide. The bacteria often live harmlessly in a person's mouth and throat. In rare instances, however, they can break through the body's immune defenses and travel to the fluid surrounding the brain and spinal cord. There they begin to multiply quickly. Soon, the thin membrane that covers the brain and spinal cord (meninges) becomes swollen and inflamed, leading to the classic symptoms of meningitis.

How do people get bacterial meningitis?

The bacteria are spread by direct close contact with the discharges from the nose or throat of an infected person. Fortunately, none of the bacteria that cause meningitis are very contagious, and they are not spread by casual contact or by simply breathing the air where a person with meningitis has been.

What are the signs and symptoms of bacterial meningitis?

In persons over age 2, common symptoms are high fever, headache, and stiff neck. These symptoms can develop over several hours, or they may take 1 to 2 days. Other symptoms can include nausea, vomiting, sensitivity to light, confusion, and sleepiness. In advanced disease, bruises develop under the skin and spread quickly.

As the disease progresses, patients of any age can have seizures.

Who is at risk for bacterial meningitis?

Anyone can get bacterial meningitis, but it is most common in infants and children. People who have had close or prolonged contact with a patient with meningitis caused by Neisseria meningitidis or Hib can also be at increased risk. This includes people in the same household or day-care center, or anyone with direct contact with discharges from a meningitis patient's mouth or nose.

How is bacterial meningitis diagnosed?

The diagnosis 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.

What complications can result from bacterial meningitis?

Advanced bacterial meningitis can lead to brain damage, coma, and death. Survivors can suffer long-term complications, including hearing loss, mental retardation, paralysis, and seizures.

What is the treatment for bacterial meningitis?

Early diagnosis and treatment are very important. If symptoms occur, the patient should see a doctor right away. Bacterial meningitis can be treated with a number of effective antibiotics. It is important, however, that treatment be started early.

How can bacterial meningitis be prevented?

• Vaccines—There are vaccines against Hib, some strains of Neisseria meningitidis, and many types of Streptococcus pneumoniae.
• Disease reporting—Cases of bacterial meningitis should be reported to state or local health authorities so that they can follow and treat close contacts of patients and recognize outbreaks.
• Treatment of close contacts—People who are identified as close contacts of a person with meningitis caused by Neisseria meningitidis can be given antibiotics to prevent them from getting the disease. Antibiotics for contacts of a person with Hib disease are no longer recommended if all contacts 4 years of age or younger are fully vaccinated.

Travel precautions

Although large epidemics of bacterial meningitis do not occur in the United States, some countries experience large, periodic epidemics of meningococcal disease. Overseas travelers should check to see if meningococcal vaccine is recommended for their destination. Travelers should receive the vaccine at least 1 week before departure, if possible.