<prompt> Epidemic of polio is due to -Type I virusType II virusType III virusCombine type II and III virus  <response>: Poliovirus tyoe 1 is responsible for most epidemics of paralytic poliomyelitis. Type 3 also causes but to a lesser extent. REF:ANANTHANARAYAN AND PANIKERS TEXTBOOK OF MICROBIOLOGY 9TH EDITION PAGE NO:490 