Poliomyelitis (polio) is a highly infectious viral disease, which mainly affects young children. The virus is transmitted to person-to-person through the faecal-oral route or, less frequently, by a common vehicle (for example, contaminated water or food). Polio upon transmission multiplies in the intestine, it then invades the nervous system that can lead to paralysis or death.

Initial symptoms of polio include fever, fatigue, headache, vomiting, stiffness in the neck, and pain in the limbs. In a small proportion of cases, the disease causes paralysis, which is often permanent and irreversible. There is no cure for polio, it can only be prevented by vaccination.