Busted! I just discovered that other viruses besides polio can cause paralysis. In India, 60,000 cases of paralysis were documented.
"In 2011, nearly 60,000 cases of acute flaccid paralysis were reported and investigated. And only one of those cases, the one that had onset on Jan 13., we were able to isolate polio viruses -- virus. The other cases were due to non-polio causes of acute flaccid paralysis."
"The Acute Flaccid Paralysis cases in India continue to increase, year by year. For the year 2009, using the WHO data, we find 50,416 total cases. Out of this total 752 were polio."
The term acute flaccid paralysis (AFP) is often used to describe a sudden onset, as might be found with polio.
AFP 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.