Polio & post-polio syndrome

Also called Infantile paralysis, Poliomyelitis, PPS

Polio is an infectious disease caused by a virus. In most people, it is harmless and causes no symptoms. However it can be very serious causing some people to become paralyzed or even die. Poliomyelitis (or "polio" for short) is defined as the paralytic disease. So only people with the paralytic infection are considered to have the disease.

The virus lives in an infected person's throat and intestines. It is most often spread by contact with the stool of an infected person. You can also get it from droplets if an infected person sneezes or coughs. It can contaminate food and water if people do not wash their hands.

Most people have no symptoms. 

Some people who've had polio develop post-polio syndrome (PPS) years later. Symptoms include tiredness, new muscle weakness, and muscle and joint pain. There is no way to prevent or cure PPS.

Fortunately there is a polio vaccine and this has wiped out polio in many countries.

(Introduction adapted from the Centers for Disease Control and Prevention)

Polio symptoms 

Most people infected with polio virus have no symptoms. If you have symptoms, they may include:

  • fever,
  • fatigue,
  • nausea,
  • headache,
  • flu-like symptoms,
  • stiff neck and back, and
  • pain in the limbs.

These symptoms usually last 2 to 5 days then go away on their own.
A smaller proportion of people with poliovirus infection will develop other more serious symptoms that affect the brain and spinal cord:

  • Paresthesia (feeling of pins and needles in the legs)
  • Meningitis (infection of the covering of the spinal cord and/or brain) occurs in about 1 out of 25 people with poliovirus infection
  • Paralysis (can’t move parts of the body) or weakness in the arms, legs, or both, occurs in about 1 out of 200 people with poliovirus infection
  • Paralysis is the most severe symptom associated with polio because it can lead to permanent disability and death.
  • Between 2 and 10 out of 100 people who have paralysis from poliovirus infection die because the virus affects the muscles that help them breathe.

Images of people who have had polio disease Center of Disease Control

Post-polio syndrome

Post-polio syndrome is a complication of polio infection that appears many years afterwards. We do not understand why, but in some people, they develop muscle pain, weakness, or paralysis as adults, 15 to 40 years later. 

Read more about post-polio syndrome.

Polio treatment

 There is no treatment to reverse the paralysis. This is why immunisation with the polio vaccine is so important. 

Prevention and polio vaccination

Polio vaccine protects children by triggering their immune system to develop antibodies to fight the polio virus.

Almost all children (99 children out of 100) who get all the recommended doses of vaccine will be protected from polio.

There are two types of vaccine that can prevent polio:

  • inactivated poliovirus vaccine (IPV). Used in NZ since 2002, this is the preferred form. 
  • oral poliovirus vaccine (OPV). Still used in some countries. 

Learn more

Polio Immunisation Advisory Centre NZ
Chapter 16: Poliomyelitis Immunisation Handbook Ministry of Health, 2014
Polio Center of Disease Control
Polio and post-polio syndrome Medline Plus

Credits: Health Navigator team.