Meningitis

Meningitis Media Backgrounder

Meningococcal disease is a serious, potentially life-threatening infection caused by the bacteria Neisseria meningitidis. Although it is most common in infants younger than one year of age, anyone can get meningococcal disease. Adolescents and college freshmen who live in dormitories are particularly vulnerable to this potentially deadly disease.

Up to 2,800 Americans get the infection each year and approximately 10 percent of them will die. Long-term effects in survivors can be severe with up to 20 percent suffering brain damage, kidney damage, hearing loss or amputation of arms, legs, fingers or toes. The devastating nature of meningococcal disease, coupled with the fact that up to 83 percent of cases among adolescents may be vaccine-preventable, make this a compelling public health issue.

Contracting Meningitis

Meningococcal disease is contagious. The disease is spread from person to person through the exchange of respiratory and throat secretions such as by coughing and sneezing. The bacteria may also be transmitted by more direct means, such as kissing. The bacteria attach to the mucosal lining of the nose and throat where they can multiply. Most people will become asymptomatic carriers of the bacteria; however, in a small percentage of people, the bacteria will penetrate the mucosal lining and enter the bloodstream. The bacteria then travel through the body rapidly and can cause damage to many organs.

The incubation period for meningococcal disease is typically three to four days, with a range of two to 10 days. Early symptoms of meningitis, the most common form of meningococcal disease, may include sudden onset of fever, headache and stiff neck. Nausea, vomiting, sensitivity to light, altered mental status and seizures often accompany these symptoms. A rash, usually dark purple and spotted, may appear on the arms, legs or torso.

Incidence of meningococcal disease ebbs and flows overall and within specific age groups. In some periods, increased rates have been noted among adolescents and college students. Lifestyle behaviors that may be relatively common among college students increase risk for meningococcal disease. These include active and passive smoking, bar patronage and excessive alcohol consumption, especially during a meningococcal disease outbreak.

Other group living situations, such as military camps and barracks, may increase the risk of meningococcal disease. Prior to routine immunization of all U.S. soldiers, outbreaks of meningococcal disease occurred with the arrival of new recruits for basic training. Routine immunization of incoming military recruits has eliminated these outbreaks.

Meningococcal disease cases that occur on college campuses induce fear among students, parents and faculty and disrupt "life as usual." Because the disease has high mortality even with the best medical treatment, students and parents often demand immediate action. Quick diagnosis of meningococcal disease is not always simple.

Early symptoms, such as fever, headache, fatigue, muscle aches and a stiff neck may look like signs of viral illnesses, like the common cold or influenza (flu). Patients may not know to seek medical care immediately, allowing the disease to quickly spread throughout the body and possibly cause death or permanent disability. Those who survive are often left with permanent injury including brain damage, hearing loss, kidney failure and amputation of arms, legs, fingers and toes.

If symptoms occur, the patient should see a doctor immediately. The diagnosis is usually made by growing bacteria from a sample of spinal fluid. The spinal fluid is obtained by performing a spinal tap, in which a needle is inserted into an area of the lower black where fluid in the spinal canal is readily accessible. Identification of the type of bacteria responsible is important for selection of correct antibiotics.

Preventing and Treating Meningitis

The most effective strategies to prevent meningococcal disease include identification of high-risk groups for preventive vaccination and antibiotic administration. The vaccine protects against four of the five most common types of meningococcal bacteria that cause invasive disease.

The U.S. Centers for Disease Control and Prevention (CDC) recommends immunization against meningococcal disease for:

All children ages 11-12 years at their preadolescent visit.
For those not previously immunized, vaccination is recommended at the time of high school entry (15 years of age).
College freshmen living in dormitories before they depart for campus.
U.S. military recruits.
Anyone who has a damaged spleen or whose spleen has been removed.
All other adolescents and college students wishing to reduce their risk of contracting the disease may elect to be immunized.

The U.S. Food and Drug Administration approved a meningococcal conjugate vaccine in 2005 for use among persons aged 11 to 55 years. The vaccine is the first quadrivalent conjugate vaccine licensed in the U.S. for the prevention of meningococcal disease. It is designed to offer protection against four serogroups of Neisseria meningitides (A, C, Y, W-135), which account for the majority of cases in this country.

Conjugate vaccines have been shown to stimulate more powerful immune responses. In general, the benefits of a successful conjugate vaccine include long-term immunity without the need for revaccination as well as decreased carriage of meningococcal bacteria among those vaccinated, possibly minimizing the spread of the disease and protection of unvaccinated persons (i.e., herd immunity).

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

Bacterial meningitis can be treated with a number of effective antibiotics. It is important, however, that treatment be started early in the course of the disease. Appropriate antibiotic treatment of the most common types of bacterial meningitis should reduce the risk of dying from meningitis to below 15 percent, although the risk is higher among the elderly. Even with antibiotic treatment, there may be serious sequelae of meningococcal infections.