What organism causes polio?
( http://www.polioalberta.ca/sappss/article_threetypes.html ) The poliomyelitis virus is an obligate intracellular parasite which has been classified into three main types: Brunhilde – named after the Rhesus monkey in which the virus was first identified, Lansing – isolated from a fatal case of bulbar polio in Lansing, Michigan and Leon – identified in a child named Leon during the Los Angeles epidemic. Because of these three separate immunological types, in theory, you can get polio three times.
