Poliovirus

What is it?

Poliovirus is the virus responsible for polio, an acute illness caused by gastrointestinal infection, that can lead to long-term disability, paralysis and death^1,2.

Since the 1980s, the World Health Organization (WHO) has led a global campaign to eradicate polio through mass vaccination programs and case surveillance³. Because of these efforts polio is now considered rare in most parts of the world, though it still circulate in some developing countries³.

The elimination of polio is considered one of the most important public health achievements. In 2000, the WHO declared the Western Pacific region polio free⁴. Today, only a few countries in Asia and Africa still have transmission of poliovirus, but the cases are sporadic and incidence is low². Afghanistan and Pakistan remain two countries where poliovirus continues to circulate².

Every year on the 24^th of October, World Polio Day is observed to raise awareness about the importance of polio vaccination, and to celebrate the global efforts that have made eradication of polio achievable⁵.

Symptoms

Most people infected with poliovirus do not develop symptoms. Around 10% may experience mild symptoms which include fever, headache, tiredness, nausea and vomiting, before making a full recovery³. In rare cases more serious symptoms include stiffness of the back and neck, and paralysis².

The incubation period typically ranges from 3 – 21 days, most commonly around 7-14 days^2,3.  Cases are considered most infectious from 7-10 days before the onset of symptoms until 7-10 days after symptoms start^2,3.

How is it transmitted?

The poliovirus is transmitted through the faecal-oral route, and occasionally the oral-oral route. After entering the mouth, the virus multiplies in the pharynx and gut, and is excreted in faeces for several weeks².  Transmission can occur through person-to-person contact with infectious oral secretions or faeces, through drinking water contaminated with untreated sewerage, and when consuming food that has been in contact with contaminated water, or prepared by someone with polio³.

At risk groups?

Children under 5 years of age are mainly affected by poliovirus, but anyone who is not immune can contract and spread polio³.

Unvaccinated people are at increased risk when travelling to countries where polio still circulates, as they may carry the infection with them while travelling to other countries or when returning home³.

Prevention?

Polio is preventable through vaccination, which has dramatically reduced the global incidence³. Children and infants are recommended to be vaccinated, and in Australia this is available through the National Immunisation Program³. Travellers to polio-affected areas, laboratory staff, and healthcare workers who may have contact with poliovirus or polio cases are recommended to receive a booster vaccination every 10 years^2,3.

Additional preventive measures include practicing good hygiene when travelling to countries with known polio circulation, including hand hygiene and ensuring food and water are clean and safe to consume³.

Key messages:

• Polio is preventable through vaccination
• Polio still poses a global risk despite being rare
• Awareness and good hygiene are critical for prevention

References

1. Australian Government. Poliovirus infection. https://www.health.gov.au/diseases/poliovirus-infection?language=en
2. Australian Technical Advisory Group on Immunisation (ATAGI). The Australian Immunisation Handbook. Australian Government Department of Health and Aged Care; 2022.
3. NSW Health. Poliomyelitis fact sheet. Updated 11 November 2022. https://www.health.nsw.gov.au/Infectious/factsheets/Pages/poliomyelitis.aspx
4. Adams A, Boualam L, Diorditsa S, et al. Maintaining polio-free certification in the World Health Organization Western Pacific Region for over a decade. J Infect Dis. Nov 1 2014;210 Suppl 1(Suppl 1):S259-67. doi:10.1093/infdis/jiu164
5. World Health Organization. World Polio Day. WHO. https://www.who.int/europe/campaigns/world-polio-day

PUBLISHED 31 OCTOBER 2025