Questions & Answers

What causes meningococcal disease?
Meningococcal disease is caused by the bacterium Neisseria meningitidis. This bacterium has at least 13 different serogroups. Five of these serogroups, A, B, C, Y, and W-135, cause almost all invasive disease. The relative importance of these five serogroups depends on geographic location and other factors.

How does meningococcal disease spread?
The disease is spread person-to-person through the exchange of respiratory and throat secretions (e.g., by coughing, kissing, or sharing eating utensils). Meningococcal bacteria can't live for more than a few minutes outside the body, so the disease is not spread as easily as the common cold or influenza.

How long does it take to show signs of meningococcal disease after being exposed?
The incubation period of meningococcal disease is 3–4 days, with a range of 2–10 days. Meningococcal bacteria can make a person extremely ill by infecting the blood (septicemia) or by infecting the fluid of the spinal cord and around the brain (meningitis). Because this disease progresses quickly, it is important to be diagnosed and start treatment as soon as possible.

What are the symptoms of meningococcal disease?
The most common symptoms are high fever, chills, lethargy, and a rash. If meningitis is present, the symptoms will also include headache and neck stiffness (which may not be present in infants); seizures may also occur. In overwhelming meningococcal infections, shock, coma, and death can follow within several hours, even with appropriate medical treatment.

How serious is meningococcal disease?
Meningococcal disease is very serious. About 9–12% of people with meningococcal disease die even with appropriate antibiotic treatment. Of those who recover, up to 20% suffer from some serious after-effect, such as permanent hearing loss, limb loss, or brain damage.

How is meningococcal disease diagnosed?
The diagnosis is made by taking samples of blood and spinal fluid from a person who is possibly infected. The spinal fluid is obtained by performing a spinal tap, where a needle is inserted into the lower back. Any bacteria found in the blood or spinal fluid is grown in a medical laboratory and identified. Meningococcal disease is relatively rare in the United States, and the symptoms can be mistaken for other illnesses, which unfortunately can lead to delayed diagnosis and treatment.

Can't meningitis be caused by a virus too?
Yes, the word "meningitis" refers to inflammation of the tissues covering the brain and spinal cord. This inflammation can be caused by viruses and fungi, as well as bacteria. Viral meningitis is the most common type: it has no specific treatment but is usually not as serious as meningitis caused by bacteria.

Is there a treatment for meningococcal disease?
Bacterial meningitis can be treated with antibiotics. It is critical to start treatment early.

How common is meningococcal disease in the United States?
There are approximately 2,000–3,000 cases of meningococcal disease each year in the United States. An estimated 110 deaths from meningococcal disease occurred in the United States in 2009.

The disease is most common in children younger than age one year and in people with certain medical conditions. The proportion of cases in adolescents and young adults has increased in recent years; the rate of invasive disease among people age 17–20 years is about twice that of the general U.S. population.

What people are at special risk for meningococcal disease?
People at risk include infants, travelers to places where meningococcal disease is common (e.g., certain countries in Africa and Saudi Arabia), people with damaged or missing spleens, and people with certain blood diseases. Other factors make it more likely an individual will develop meningococcal disease, including having a previous viral infection, living in a crowded household, having an underlying chronic illness, and being exposed to cigarette smoke (either directly or second-hand).Studies have also shown that college freshmen who live in dormitories are at an increased risk of meningococcal disease compared with others their age.

How common is meningococcal disease in the world?
Meningococcal disease is common in certain parts of the world, especially the area of Africa which is known as the "meningitis belt." Serogroup A is responsible for most of the meningococcal disease in sub- Saharan Africa, but this serogroup is uncommon in the United States.

Can you get meningitis more than once?
Yes. Meningitis can be caused by different subtypes of the meningococcal bacterium, by other bacteria such as Streptococcus and Haemophilus, as well as by viruses and fungi. Even being vaccinated against Neisseria meningitidis or having had the disease will not protect you against these other sources of infection.

If a child is diagnosed with meningococcal disease, can anything be done to protect the other children with whom he has contact?
Individuals who have been exposed to a person with bacterial meningitis can be protected by being started on a course of antibiotics immediately (ideally within 24 hours of the patient being diagnosed). This is usually recommended for household contacts and children attending the same day care or nursery school. Older children and adults (e.g., who are in the same school or church) aren't usually considered exposed unless they have had very close contact with the infected person (e.g., kissing or sharing a glass).

In addition to the antibiotic treatment, vaccination may be recommended for people two years of age and older if the person's infection is caused by meningococcus type A, C, Y, or W-135, all of which are contained in the meningococcal vaccine.

Questions and answers about meningococcal disease vaccine

Technical content reviewed by the Centers for Disease Control and Prevention, March 2011