Also known as poliomyelitis, polio is a highly infectious viral disease. Although most of the world's countries are free from polio, this condition still exists in parts of Africa and south Asia. In particular, it is found in areas where water treatment and sanitation facilities are not properly maintained or nonexistent.
Although children under 3 years of age represent more than half of all cases, polio can affect people of any age.
According to the Pan American Health Organization, Canada has been free of polio since 1994. The World Health Organization is at the heart of a plan to help make the world free from the disease. Through vaccination, the spread of polio and the complete removal of the disease from the human population is possible. The number of polio-endemic countries in 1988 was over 125; in early 2006, this number had been reduced to just 4, and the number of reported cases decreased from an estimated 350,000 in 1988 to 416 in 2013.