What is meningococcal disease?

Meningococcal disease is a bacterial infection. It occurs commonly in two forms: inflammation of the membranes covering the brain and spinal cord (meningococcal meningitis) or a severe blood infection (meningococcemia).

The bacteria that causes meningococcal disease, Neisseria meningitidis, first infects the mucous membranes of the nose and throat, usually without any symptoms. In fact, 5 percent to 10 percent of the population may carry the bacteria at any given time without becoming ill. In a small proportion of infected persons, the bacteria passes through the mucous membrane and reaches the blood stream, causing meningococcal meningitis or meningococcemia. When illness occurs, it does so within four days of exposure, but can develop as long as 10 days later. The disease is most common during winter and spring.

How is meningococcal disease spread?

Meningococcal infection is not highly contagious. Transmission from person to person occurs through direct contact with nose and throat secretions. An infected person can transmit the disease by coughing or sneezing directly into the face of others, kissing a person on the mouth, or sharing a glass or cup.

Because it is possible to harbor the bacteria in the nose and throat yet not develop symptoms, healthy persons as well as persons who are ill may spread the bacteria to others. The bacteria is not transmitted by casual contact, such as sitting in the same room as an infected person or passing an infected person in a hallway or on a sidewalk.

What are the symptoms of meningococcal disease?

Meningococcal disease usually starts with a sudden onset of fever and headache. A stiff neck may be present and later a red rash often develops. Nausea and vomiting also can occur but alone are not sufficient to suggest meningococcal disease. In newborns and small infants, the classic findings of fever, headache and neck stiffness may be absent or difficult to detect, and the infant may show only extreme listlessness, irritability, poor feeding and sometimes vomiting. In severe cases, as the disease progresses, both infants and older patients may have seizures and decreased alertness advancing to coma.

Who is most susceptible to meningococcal disease?

Meningococcal disease is primarily a disease of young children. About 50 percent of cases occur in infants and children younger than 4 years of age. Adults at increased risk of meningococcal disease include those who have recently been brought together as a group and housed under crowded living conditions, such as in barracks or institutions. College freshmen, particularly those living in dormitories, are at modestly increased risk. Household contacts of cases, who are at greatest risk of meningococcal disease, have only about three to 10 chances in 1,000 of developing the disease. Most persons are not susceptible to meningococcal disease because they have had prior exposure and have become immune.

In Illinois, the five-year median (2002-2006) for meningococcal disease is approximately 46 cases a year.

Fewer than 10 percent of all meningococcal disease cases are fatal. Death occurs more often in meningococcemia (as high as 17 percent) than in meningococcal meningitis (approximately 7 percent).

How is meningococcal disease treated?

Cases of meningococcal disease require immediate medical treatment by a physician. The diagnosis is usually made by growing bacteria from a sample of blood or spinal fluid. The spinal fluid is obtained by performing a spinal tap, in which a needle is inserted into an area in the lower back where fluid in the spinal canal is readily accessible. Intravenous penicillin or other antibiotics are used to treat infected persons.

How can meningococcal disease be prevented?

Risk of transmission of meningococcal infection can be reduced by practicing good hygiene. Persons should cover their noses and mouths when sneezing or coughing and discard used tissues promptly. Wash hands thoroughly following exposure to respiratory secretions. To avoid exposure, persons should not share cigarettes, straws, cups, glasses or eating utensils. Eating and drinking utensils can be used by others only after they have been washed.

It is recommended that household contacts and others who have had close personal contact with infected persons receive a short course of certain antibiotics, which kill bacteria living in throat secretions. Since the recommendations for use of preventive antibiotics vary according to the specific situation, it is best to consult a physician or local health department for advice. Even if an antibiotic is taken, close contacts should be observed and any sign of disease promptly evaluated by a physician.

Meningococcal vaccine is effective on certain types of Neisseria meningitidis but is only recommended when there is a high incidence of cases in a limited geographic area and for persons traveling to countries where epidemics are in progress.

It is recommended that health care providers routinely vaccinate persons age 11 to 18 years with meningococcal vaccine to improve vaccination coverage in this age group. College freshmen living in dormitories are at increased risk for meningococcal disease and, if not previously vaccinated, they should be vaccinated before entering college.