POLIO

Polio (also called poliomyelitis) is a contagious, historically devastating disease that was virtually eliminated from the Western hemisphere in the second half of the 20th century. Although polio has plagued humans since ancient times, its most extensive outbreak occurred in the first half of the 1900s before the vaccination created widely available in 1955.

Polio is a highly infectious disease caused by a virus. It invades the nervous system, and can cause total paralysis in a matter of hours. The virus enters the body through the mouth and multiplies in the intestine.


Initial symptoms are fever, fatigue, headache, vomiting, and stiffness in the neck and pain in the limbs. One in 200 infections leads to irreversible paralysis (usually in the legs). Among those paralyzed, 5% to 10% die when their breathing muscles become immobilized.

Polio is transmitted primarily through the ingestion of material contaminated with the virus found in stool (poop). Not washing hands after using the bathroom and drinking contaminated water were common culprits in the transmission of the disease.

Although the acute illness usually lasts less than 2 weeks, damage to the nerves could last a lifetime. In the past, some patients with polio never regained full use of their limbs, which would appear withered.

Overall, since the Global Polio Eradication Initiative was launched, the number of cases has fallen by over 99%. In 2010, only four countries in the world remain polio-endemic. Persistent pockets of polio transmission in northern India, northern Nigeria and the border between Afghanistan and Pakistan are key epidemiological challenges.

Four countries (Afghanistan, India, Nigeria, and Pakistan) still have polio circulating, and the virus could be introduced to other countries. If the polio virus is imported into a country where not enough people have been immunized, there's the risk that it could spread from person to person. That's what has happened in some countries in Africa and Asia. So until it has been eliminated worldwide, it's important to continue vaccinating kids against polio.

article source: wikipedia