Acute Flaccid Paralysis (AFP)

What is acute flaccid paralysis (AFP)?

Acute flaccid paralysis (AFP) describes a group of conditions with set symptoms.  AFP is identified by the sudden weakening or loss of muscle tone in children less than 15 years old, without a clear cause.  Viruses or conditions, such as poliovirus, West Nile virus, or Guillain-Barré syndrome, may cause AFP.

AFP is reported to local public health because of its possible link to polio.  With the availability of the polio immunization, Canada has been polio free for the last 20 years.  Since there is no cure for polio, monitoring and prevention is really important.

What are symptoms of AFP?

  • Quick onset of weakness or paralysis (flaccid) without other obvious cause.  It may affect one side or both sides equally.
  • Fever, sore throat, headache, nausea, constipation and/or tiredness may be present with AFP related to polio.

How does AFP spread?

It is specific to the cause of the paralysis.  Each condition may spread differently.  For example, polio can spread through contact with the stool (poop) or through the air when a person coughs or sneezes.

How long is it contagious?

This depends on the cause of the AFP.  For example, poliovirus may spread as long as it is found in the stool.

How is AFP treated?

If your child develops sudden weakness or paralysis, see your health care provider right away.  They will conduct a variety of tests to see what the cause is.  Treatment includes supportive care for symptoms.

How is AFP prevented?

You can lower your child’s risk by:

  • Making sure you and your family are up-to-date on your immunizations, especially against polio.
  • Washing your hands often for at least 15 seconds with warm water and soap, especially after handling diapers and using the washroom.  Avoid touching your face before you wash your hands.
  • Practicing respiratory manners, such as coughing and/or sneezing into your elbow or tissue.
  • Cleaning and disinfecting surfaces that are often touched by others (such as doorknobs, phones, keyboards).
  • Staying at home if you are sick.
Photo of a baby receiving vaccine injection

For more information, contact the Health Unit or speak to your health care provider.


  • American Academy of Pediatrics. (2018). Red book: 2018-2021 Report of the committee on infectious diseases (31st ed.). D.W. Kimberlin, M.T. Brady, M.A. Jackson, & S.S. Long (Eds.). Itasca, IL.
  • American Public Health Association. Control of communicable diseases manual (20th ed.). D.L. Heymann (Ed.). Washington, DC.