In 1988, the World Health Organization (WHO) called for the global eradication of polio. Within a decade, one of the three poliovirus strains was already virtually eradicated — meaning a permanent reduction of the disease to zero new cases worldwide.
Polio, also known as poliomyelitis, is an extremely contagious disease caused by the poliovirus. It attacks the nervous system and can lead to full paralysis within hours. The virus enters through the mouth and multiplies in the intestine. Infected people shed poliovirus into the environment by the faecal-oral route.
About one in every 200 infections results in irreversible paralysis (usually affecting the legs). Of those who become paralysed, 5–10% die due to immobilised breathing muscles.
