Meningococcal Disease is a potentially-life threatening bacterial infection caused by Neisseria meningitidis, a common bacterium that can be present in the throat and nose of healthy people. For reasons that are not well understood, sometimes the bacteria invade the body to infect the lining of the brain (causing meningitis) or the bloodstream (meningococcemia). These invasive diseases are characterized by rapidly worsening conditions that are sometimes fatal unless recognized and treated promptly. Brain damage, hearing loss, limb damage, or kidney failure can also occur.
How common is meningococcal disease?
Meningococcal disease is uncommon in the United States, occurring at a rate of 1 in 100,000 people per year. Illness can occur at any age, and is more common in children. Approximately 100 cases of meningococcal disease occur each year on college campuses, representing about 3% of all U.S. cases. UW-Madison has experienced an average of one case per year over the last decade. College students living in residence halls, particularly freshman, are at an increased risk of developing meningococcal disease compared to other college students. It is important for students to become familiar with meningococcal disease and to get the meningococcal vaccine.
How do people get infected with meningococcal bacteria?
Meningococcal bacteria are spread from person to person by direct contact with an infected person's oral or nasal secretions. Approximately 10% of the general population carries the meningococcal bacteria in the nose and throat in a harmless state. Fortunately, very few people ever develop invasive disease even if they are carriers. The low occurrence of illness after exposure suggests that an individual's personal health status, rather than bacterial factors, plays an important role in determining who may develop the disease. Meningococcal bacteria cannot live for more than a few minutes outside the body. The bacteria are not transmitted in water supplies, swimming pools, or by casual contact in classrooms, restaurants, bars, or other social settings. Friends, classmates, or children who are not directly exposed to an infected person are not at risk and do not require any treatment. Persons who have had recent intimate or direct exposure to someone with meningococcal disease may be at increased risk for contracting or spreading meningococcal disease and should receive preventative medication. Exposure is defined as kissing, sharing eating or drinking utensils, or sharing cigarettes with a person who has recently developed meningococcal disease.
What are the symptoms of meningococcal disease?
Meningococcal disease can cause an individual to become very ill, very quickly. The most common symptoms include high fever (greater than 101°F) accompanied by severe headache, neck stiffness and confusion. Vomiting, lethargy or rashes may also occur. Anyone with these symptoms should contact a clinician or go to an emergency room immediately. Meningococcal disease is sometimes misdiagnosed as something less serious, because symptoms may be similar to the flu. If not treated immediately, the disease can progress rapidly and can lead to shock and death within a few hours.
Why is meningococcal disease so dangerous?
Meningococcal bacteria are particularly dangerous because they can produce large quantities of a chemical poison called endotoxin. If the bacteria enter he bloodstream and multiply, endotoxins damage small blood vessels throughout the body, resulting in low blood pressure and shock. The damage this causes is sometimes irreversible and can happen very quickly
What is the treatment for meningococcal disease exposure?
People who have been exposed (as defined above) to oral or nasal secretions of a person with meningococcal disease may need to take antibiotics to prevent spread of the infection. The purpose of the antibiotics is to eliminate the meningococcal bacteria from the throat (carrier state). People who have not had direct exposure to oral or nasal secretions do not need to be treated.
What is the treatment for meningococcal disease illness?
The majority of patients who are diagnosed early in the course of their illness can be effectively treated with antibiotics and experience complete recovery. Occasionally, meningococcal infection is overwhelming and defies prompt medical treatment.
What is the new recommendation for meningococcal vaccination?
In February 2005, the CDC's Advisory Committee on Immunization Practices recommended that all adolescents entering middle school, all adolescents entering high school, and all college freshmen living in dormitories receive a newly licensed meningococcal vaccine.
What prompted this recommendation?
In January, 2005 the Food and Drug Administration approved a new meningococcal vaccine (Menactra®) for use in the United States that will benefit all adolescents and young adults. Prior to 2005, the existing recommendation was only that college students should "consider" vaccination, since the previous vaccine was not as effective and did not provide long-term immunity.
How is the new vaccine better than the old vaccine?
The new vaccine is a conjugate vaccine and offers improved efficacy with a longer duration of protection. Unlike the previous vaccine, it is not likely to require repeated doses. In addition, the new vaccine protects against infection, not just disease. This means that it prevents people from becoming carriers of the meningococcal bacteria and can reduce transmission from person to person.
What are the benefits and limitations of the vaccine?
The new meningococcal vaccine is estimated to be 90 to 95 percent effective in preventing meningococcal disease caused by four common strains of the bacteria. However, about 30 percent of cases in adolescents and college students are caused by a strain (serogroupB) that is not included in any vaccine. Unfortunately, researchers have not been able to make an effective vaccine to use against serogroupB meningococcal disease. Because of this limitation, vaccination reduces the overall risk of developing meningococcal disease by about 65 percent. This vaccine does not provide any protection against other types of bacterial or viral meningitis.
If a student received the old vaccine should they be revaccinated?
No. The previous vaccine provides 3 to 5 years of protection, which is adequate for most college students. Since the primary risk for disease is among freshman, revaccination after the first year of college would provide little benefit. However, if a student was first immunized more than three years prior to beginning college, they may wish to be revaccinated. We encourage these students to discuss their situation with their family health care provider.
Is the new vaccine safe?
Yes. The technology used to make conjugate vaccines is the same as several other vaccines given to children and has a proven safety record. Like most vaccines, mild soreness may occur in the arm where the shot was given. Serious problems such as allergic reactions are very rare. It cannot cause meningococcal infection or disease.
What are some ways to reduce the risk of contracting meningococcal disease?
A lifestyle that includes a healthy diet, adequate sleep and rest, and regular exercise helps keep the immune system healthy and as strong as possible. Avoiding respiratory illness and tobacco smoke may help to protect from invasive meningococcal disease.
For more information, contact your local health department.