How is polio transmitted?

A person who carries poliovirus can release it in their stool, sometimes without obvious illness. The virus may then move from unwashed hands to food, drinking water, surfaces or another person's mouth. Close contact can therefore matter, especially where toilets, clean water and handwashing are limited. Respiratory secretions may also contribute to spread during close contact.

Transmission is not the same as diagnosis. Someone with diarrhoea, fever or weakness may have many possible causes, and testing and clinical assessment are needed to identify poliovirus.

Wash hands carefully with soap and water after using the toilet, after changing nappies and before preparing or eating food. Use safe drinking water, clean bathroom surfaces, and avoid sharing food or drinks with someone who is unwell. If poliovirus exposure is suspected, contact a healthcare professional promptly and follow local public-health advice.

Routine vaccination is the strongest practical protection against polio. Check that children have received the vaccines recommended for them; see [Childhood Immunisation](/treatments/preventive-care-and-vaccination/childhood-immunisation/).

Seek urgent medical help for new weakness in an arm or leg, difficulty walking, trouble swallowing, breathing difficulty, or sudden loss of movement. These signs need prompt assessment regardless of whether polio is confirmed. Seek advice after a known exposure, particularly for an unvaccinated child or a person with a weakened immune system.

Ask whether vaccination is up to date, whether testing is needed after a possible exposure, and which hygiene or isolation measures apply while symptoms are being assessed.