'Before you believe that polio has been eradicated, have a look at this graph of AFP and Polio. If you are wondering why there is no data prior to 1996, go to the WHO website for AFP and you will see that there is no data prior to 1996, and note that AFP conitnues to rise in 2011.
Acute Flaccid Paralysis (AFP) is just another name for what would have been called polio in 1955, and is used to describe a sudden onset of paralysis. It is the most common sign of acute polio, and used for surveillance during polio outbreaks.
AFP is also associated with a number of other pathogenic agents including enteroviruses, echoviruses, and adenoviruses, among others. But in 1955, there was no attempt to detect anything other than polio in cases of AFP. Once the vaccine was mass marketed, the game changed.'