Polio (poliomyelitis)

What is polio?

Polio is a highly contagious viral infection that can cause paralysis and death. It is also known as poliomyelitis, or infantile paralysis.

Polio was once a widespread disease that affected many people. Now, due to vaccination, polio has been got rid of in most of the world.

Australia began routinely vaccinating against polio in 1956. The last polio epidemic in Australia was in 1961-1962. Australia was officially declared polio-free in 2000.

What causes polio?

Polio is caused by the poliovirus.

The polio virus is very contagious. It is spread by contact with the saliva or faeces (poo) of infected people. This means polio can spread through contact with:

• contaminated food or water
• droplets produced when an infected person coughs or sneezes

Poliovirus first infects your gastrointestinal tract. In some people, it moves through the bloodstream and also infects the central nervous system.

Since 2014, poliovirus has only been found in Afghanistan and Pakistan. Unvaccinated people may become infected if they travel to areas with polio. They may take the infection with them to polio-free countries, including Australia, and could infect others.

This is why immunisation is still important, to prevent cases of polio from coming back.

What are the symptoms of polio?

Around 19 out of every 20 people with poliovirus have no symptoms. You may be unaware that you have the infection. This means the virus can infect many people before it is detected.

Poliovirus can be in your faeces for up to 35 days before you have any symptoms.

Some people infected with poliovirus have flu-like symptoms, including:

• fever
• fatigue (tiredness)
• headache
• nausea and vomiting
• sore throat
• pain or stiffness in the back, neck, arms or legs
• weak or tender muscles

These symptoms can last for up to 10 days.

The virus can stay in your faeces for up to 6 weeks once symptoms have appeared.

Acute flaccid paralysis

Less than 1 in every 100 people who catch poliovirus develop severe muscle weakness. This is also known as acute flaccid paralysis (AFP).

This can affect the muscles in your:

• arms and legs
• head and neck
• diaphragm, which is a muscle needed for breathing

Acute flaccid paralysis can stop you from moving and breathing properly.

Most people recover completely. However, the paralysis is permanent in some people. Severe cases of acute flaccid paralysis, where the breathing muscles become paralysed, can be fatal (cause death).

When should I see my doctor?

If you have symptoms of polio, see a doctor immediately.

How is polio diagnosed?

To diagnose polio, your doctor will first examine you. They will ask if you have:

• travelled to a country which still has polio
• been in contact with someone who has travelled to a country with polio

Your doctor will confirm a polio diagnosis by testing a sample from your:

• throat
• stool (poo)
• cerebrospinal fluid (the fluid surrounding your brain and spinal cord)

Polio is a notifiable disease. If you are diagnosed with polio, your doctor will tell your local public health unit. They will try to trace the people you have been in contact with. This helps prevent further spread of the disease.

How is polio treated?

There is no specific treatment for polio. Some treatments can help you recover and prevent complications. These include:

• physiotherapy to aid recovery from paralysis
• intensive care in hospital, including help with breathing

In the past, people with polio who had trouble breathing were placed in special ventilators called iron lungs.

Can polio be prevented?

Polio can only be prevented by immunisation.

Australia’s National Immunisation Program recommends the polio vaccine for:

• children and infants
• adults who are at higher risk of polio

Children under 5 years and young adults are most at risk, although anyone can get polio.

Adults can be at high risk of catching polio if they:

• travel to countries with polio
• live or work with people with polio

What are the recommendations for the polio vaccine

Vaccination is your best protection against polio. Find out more about the polio vaccine in the table below.

There are different vaccines available for polio. Talk to your doctor about which one is best for you.

Talk with your doctor if:

• you were not vaccinated against polio as a child
• you are not sure whether you are vaccinated

They can tell you whether you need a catch-up vaccine.

How is the spread of polio prevented?

If you are travelling to a country that has polio, you should:

• practice good hygiene
• only drink clean water
• only eat food that has been prepared properly, using clean water

Complications of polio

Polio may have lasting consequences and can be fatal.

People who have survived polio may have post-polio syndrome. This is when muscle weakness returns many years after the original infection.