Polio (poliomyelitis)

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 eliminated in most parts of the world.

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

Polio is caused by the poliovirus.

Poliovirus is very contagious and spreads by contact with infected saliva or faeces (poo). 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 (gut). In some people, it moves through the bloodstream and also infects the central nervous system.

Unvaccinated people may become infected if they travel to areas with polio. They may also take the infection with them to polio-free countries, including Australia, and could infect others.

For this reason, immunisation is still important to prevent the return of polio to the community.

Most people with poliovirus have no symptoms, so you might not know that you have the infection. Those who do get symptoms can have poliovirus for up to 35 days before the symptoms appear. This means the virus can infect many people before it is detected.

Some people infected with poliovirus have early symptoms similar to those of gastroenteritis ('gastro') that last for up to 5 days, including:

• diarrhoea
• nausea and vomiting
• fever
• fatigue (tiredness)

Other symptoms of poliovirus include:

• sore throat
• headache
• pain or stiffness in the back or neck
• sensitivity to light

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 develops severe muscle weakness. This is also known as acute flaccid paralysis (AFP). This muscle weakness can affect 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, but for some people, the paralysis is permanent. Severe cases of acute flaccid paralysis, where the breathing muscles become paralysed, can be fatal (cause death).

If you have symptoms of acute flaccid paralysis, see a doctor immediately. If you have gastroenteritis-like symptoms and are severely dehydrated, see a doctor.

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

• been vaccinated against polio
• travelled to a country that 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 stool (poo) sample
• doing a throat swab

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.

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'.

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

While children under 5 years of age and young adults are most at risk, 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
• work in a lab with polio

Polio may have lasting effects and can be fatal.

Some people who have had polio may develop post-polio syndrome. This is when muscle weakness returns many years after the original infection.

For more information about polio, visit the Polio Australia website.

Read more about polio immunisation on the National Immunisation Program's website.

Immunisation recommendations for Australian travellers can be found on the Department of Health and Aged Care website.

If you need advice on what to do next, call healthdirect on 1800 022 222 to speak with a registered nurse, 24 hours, 7 days a week (known as NURSE-ON-CALL in Victoria).

Languages other than English

Sharing Knowledge About Immunisation has polio fact sheets for each age in a number of community languages:

• 2 months
• 4 months
• 6 months
• 4 years

Information for Aboriginal and/or Torres Strait Islander peoples

For more information about immunisation for Aboriginal and/or Torres Strait Islander people, visit the Department of Health website.