What causes polio and what are its symptoms?

Poliovirus usually enters through the mouth and can spread when handwashing, sanitation, or water safety is inadequate. Many infected people have no symptoms. Others develop a mild illness with fever, tiredness, headache, nausea, vomiting, sore throat, or stomach upset. In a smaller group, the infection affects the nervous system and may cause severe headache, neck or back stiffness, muscle pain, weakness, or paralysis.

New weakness can begin suddenly and may affect one limb or several muscles. Breathing or swallowing muscles can also be affected. These symptoms have other possible causes, so urgent assessment is needed rather than trying to diagnose polio at home.

Seek medical advice promptly for fever with new weakness, stiffness, or difficulty walking, particularly after travel or contact with a suspected case. Wash hands thoroughly after using the toilet and before handling food, use safe water, and avoid sharing personal items during an unexplained infectious illness. Check that you and your children are protected through Childhood Immunisation and follow public-health instructions if exposure is suspected.

Call emergency services for sudden or worsening weakness, inability to stand or walk, trouble breathing, choking, difficulty swallowing, or a rapidly changing level of alertness. A child with limb weakness, an unusual limp, or loss of previously acquired movement needs urgent assessment. Keep the person safe from falls while waiting for help.

Ask whether symptoms or travel history require testing, how to reduce household spread, and whether any immunisation doses are due.