Polio? What is polio? The only time the majority of people in our world encounter that name is when a physician encourages us to have our children immunized against polio. Polio or poliomyelitis is disease caused by a virus called the polio virus. The virus initially infects either the mouth or the intestines then gets into the bloodstream where it is carried to the spinal cord. Once in the spinal cord the virus reproduces causing damage to the nerves. In severe cases of poliomyelitis the patient becomes paralyzed. The polio virus is highly infectious and can be transmitted person-to-person by a fecal-oral route. There are three different types (P1, P2, and P3) of the polio virus that cause poliomyelitis and a person could theoretically have polio three different times since infection with one type of the virus does not protect against infection with the other types of the virus.
A fecal-oral route of transmission is a transmission route in which infected feces (excrement, bowel movement) from one person ends up in the mouth of an uninfected person. Many people do not wash their hands after using the restroom. After changing a diaper some people forget or are distracted and do not wash their hands.
Even though polio is rare today it was at one time a very common disease. Over 13,000 people each year developed the paralyzing form of polio in the United States during the 1940's. Most of those with paralytic polio were children. Fortunately, even in that time, less than one in 100 people infected with polio developed paralysis. Most (95%) of the people infected with polio did not have any symptoms. Around 4-8% of people infected with polio had flu-like symptoms. Another 1-2% developed an infection of the membranes surrounding the brain (aseptic meningitis). All of those with flu-like symptoms got over the infection with no long-term problems and nearly every one that got aseptic meningitis were fine in 2 to 10 days. The major problems were associated with those that developed paralytic polio. Many people with paralytic polio got better and their muscles started functioning again. However, there were those every year that did not get better and were either paralyzed for life usually on one side or in some cases died. In the temperate regions of the world, summer was a common time to get polio and many parents kept their children at home in hopes of keeping them safe from polio.
It wasn't until the mid 1950's that the vaccine developed by Jonas Salk started to drastically reduce the number of polio victims in the world. Another vaccine developed by Albert Sabin (introduced in 1961) continued the decline in
