What is meningococcal disease?

Meningococcal disease can refer to any illness caused by the bacterium Neisseria meningitidis, which is also called the "meningococcus." 

• Meningococcal meningitis (a type of bacterial meningitis) occurs when N. meningitidis causes inflammation of the tissue surrounding the brain and spinal cord (the meninges).
• Meningococcemia occurs when N. meningitidis enters the blood stream.
• Pneumonia occurs when N. meningitidis infects the lungs.

What is Neisseria meningitidis?

Neisseria meningitidis is a bacterium that lives in the noses and throats of 5 to 10 percent of the population but rarely causes serious disease. Serious "invasive" disease occurs when N. meningitidis spreads through the body via the blood stream after penetrating the mucous membranes of the nose and throat.

There are 13 types (serogroups) of Neisseria meningitidis, nine of which cause invasive disease (A, B, C, D, X, Y, Z, 29E and W-135). Serogroup B is by far the most common cause of meningococcal disease in Oregon, accounting for about 50% of cases. Meningococcal vaccines are effective against serogroups A, C, Y and W-135; until recently, there were no serogroup B meningococcal vaccines licensed for use in the United States.

Viral infections, household crowding, chronic illnesses and both active and passive smoking increase the risk of meningococcal disease. College freshmen, particularly those living in residence halls, have a slightly higher chance of getting meningococcal disease than people the same age who do not attend college.

What are the signs and symptoms of invasive meningococcal disease?

Meningococcal meningitis: Key symptoms are sudden high fever, headache and stiff neck.

Meningococcemia: Key symptoms are fever and rash. Meningococcemic rash is dark purple and non-blanching (it doesn't disappear when you press it). The rash develops rapidly and usually appears on the armpits, groin, and ankles, and in areas where elastic pressure is applied (like underwear and socks).

Other signs and symptoms: Nausea, vomiting, weakness, low blood pressure, discomfort looking into bright lights, severe aches or pains, cold chills, rapid breathing, confusion, sleepiness and, in the extreme, delirium, seizures, and coma.

Without intravenous antibiotic treatment, most patients with invasive meningococcal disease will die.

How is meningococcal disease diagnosed?

Meningococcal disease is diagnosed by culturing N. meningitidis from a normally sterile site like spinal fluid or blood (not a sputum specimen or throat swab).

How does Neisseria meningitidis spread?

Fortunately, meningococci aren't nearly as contagious as the common cold or influenza; they are not spread by simply breathing the same air where a person with meningococcal disease has been.

Meningococcal disease spreads among people through the exchange of saliva and other respiratory secretions during activities like coughing, sneezing, kissing, and chewing on toys. Close contacts of cases (like household members) have a higher chance of developing illness; casual contacts are not at elevated risk.

How soon after exposure do symptoms appear?

Usually 3 to 4 days, but may range from 2 to 10 days.

How long are people with meningococcal disease contagious?

People are contagious as long as bacteria are present in the nose or throat, especially during the three days before symptoms begin. Those exposed to people with meningococcal disease seven or more days before the infected person becomes ill are not likely to become ill themselves.

How common is meningococcal disease?

The rate of meningococcal disease in Oregon in 2013 was 0.3 cases per 100,000 Oregonians (compared to 0.13 per 100,000 Americans). While meningococcal disease is more common in Oregon than it is in the United States as a whole, it is still a rare disease that has been getting rarer; the incidence rate has decreased 75% since 1996.

What happens when a case of meningococcal disease occurs?

Local health departments are notified when a doctor suspects meningococcal disease and when laboratories culture N. meningitidis from blood or spinal fluid. Local health department staff then interview the individual, their parents or any others who may have information about possible sources of infection and people who may have been exposed, including:

• Household members;
• Day-care facility classmates;
• Close, face-to-face contacts who were in the same room or other enclosed space with the infected person for at least 4 hours (all together) within seven days before the infected person became ill; and
• Anyone directly exposed to the patient's saliva (by kissing, sharing utensils or drinks, mouth-to-mouth resuscitation, etc.).

How are potentially exposed people protected from meningococcal disease?

The antibiotic Rifampin should be prescribed for all household members and other exposed persons. Ceftriaxone or Ciprofloxacin is used when Rifampin cannot be. Antibiotic prophylaxis should be instituted as soon as possible after exposure. If more than fourteen days have passed since the last contact with the case, medication is likely to be of little benefit.

Co-workers and K-12 classmates usually don't require antibiotic prophylaxis.

Vaccination is not recommended to protect contacts of isolated cases, but vaccine may be used to control outbreaks of some types of meningococcal disease.

Who should get meningococcal vaccine?

A meningococcal conjugate vaccine (MCV4) is effective against four serogroups (A, C, Y, and W-135) of N. meningitidis. While the vaccine is not effective against serogroup B, it is still important for adolescents to be immunized between 11-12 years of age with a booster given between 16-18 years of age, per current CDC ACIP recommendations. Additionally, individuals 2-55 years of age are recommended to receive this vaccine if they are at higher risk for meningococcal disease.

Those at higher risk include:

• College freshmen living in dormitories;
• Military recruits;
• People involved in meningococcal disease outbreaks caused by serogroups A, C, Y, W-135A;
• People who have certain immune system disorders called "terminal complement component deficiencies;"
• People who have no spleen or who have spleens affected by sickle cell disease;
• Research, industrial and clinical laboratory personnel who are exposed routinely to Neisseria meningitidis in solutions that might become aerosolized;
• Travelers visiting the "meningitis belt" in sub-Saharan Africa (Senegal in the West to Ethiopia in the East) during the "dry season" (December to June); and
• Travels to Mecca (Saudi Arabia) during the Hajj.

A meningococcal polysaccharide vaccine (MPSV4) also protects against disease due to serogroups A, C, Y, and W-135. This vaccine is available and is recommended for those 55 and older at higher risk of meningococcal disease.

How can individuals reduce their risk of contracting meningococcal disease?

• Stop smoking;
• Don't let children be in rooms where people are smoking;
• Get meningococcal vaccine according to the recommendations above;
• Prevent upper and lower respiratory tract infections by receiving influenza vaccine (and possibly pneumococcal vaccine) and avoiding close contact with people with coughs and colds;
• Get pneumococcal vaccine if it is recommended for you.