Invasive meningococcal disease (IMD) is a serious bacterial infection caused by the bacterium Neisseria meningitidis (commonly known as meningococcus). Five different groups of bacteria are most commonly associated with IMD in Canada.

Some people carry the bacteria at the back of their throat or in their nose without ever feeling sick. In very rare cases, these bacteria overcome the body’s natural defenses and can cause 2 serious diseases:

  1. Meningitis, an infection of the lining of the brain and spinal cord
  2. Septicemia, a serious blood infection that can damage organs in the body

IMD is rare, but when it does occur it is most common in children under 5 years old, teens and young adults. However, people at any age can get the disease. The best protection is vaccination.

How meningococcal disease is spread

IMD can be passed from person to person. The bacteria are spread by direct contact with saliva from the mouth or mucus from the nose of an infected person. This can happen through close contact such as:

  • living in the same household
  • kissing, or sharing items such as drinking bottles, lipstick, cigarettes, drinks, cutlery or toys

An infected person can spread the disease for 7 days before becoming sick. Antibiotics can usually stop the bacteria from spreading within 24 hours of starting treatment.

Risks of meningococcal disease

IMD can be deadly, and death can happen in as little as a few hours. In non-fatal cases, up to one-third of people with IMD will have a permanent disability, such as:

  • hearing loss, brain damage or seizures
  • people who get a blood infection may require amputation of an arm or leg

IMD is serious and it’s still common around the world. About 200 cases occur in Canada every year, often during the winter and spring. It can be difficult to diagnose because the early symptoms can be similar to a bad cold or the flu. The disease can also progress very rapidly, so quick medical attention is extremely important. Without treatment, almost all children who get it will die or have damage that lasts the rest of their lives.


Symptoms can appear within hours or over several days, and include:

  • sudden fever
  • headache
  • stiff neck
  • nausea
  • vomiting
  • increased sensitivity to light
  • confusion
  • A rash on the body that spreads quickly. It begins as reddish or purplish spots that don’t disappear when pressed.

In severe cases, coma may also occur. In infants, the common symptoms may be difficult to notice. Instead, symptoms may include irritability (feeling crabby or in a bad mood), difficulty waking, difficulty feeding and vomiting.

Meningococcal disease should always be treated as a medical emergency. If you think that you or your family member have any of these symptoms, call your health care provider right away.

Protection and prevention

You can protect your children against many types of meningococcal disease with a safe and effective vaccine. The meningococcal vaccine is given:

  • at 1 year of age
  • to children in Grade 7

The vaccine may also be given to people who have a higher risk of getting meningococcal disease (for example, if they have a medical condition).

Vaccinations are the best way to protect against meningococcal disease. The vaccines are part of the publicly funded vaccination schedule and are offered free to all children in Ontario. The meningococcal vaccines are required for children to attend school in Ontario and for children attending a daycare centre, unless they have a valid exemption.

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