3 strains 5 outcomes. There are 3 strains of the virus. Infected people can have 5 basic outcomes. 90-95% are asymptomatic, showing no illnes. Abortive illness is a brief flu like process. Nonparalytic polio is longer & marked by neck&spine rigidity but no parylisis. Paralytic polio adds paralysis to the symptoms & some die. Some survivors of paralytic polio have a post polio syndrome (new weakness) 30-40 yrs later.
Polio is motor disor. There are 3 types of polio virus and a few other viruses that can mimic polio. Polio virus may cause an encephalitis, from which most recover. However, it causes its major damage when it effects the motor nerve cells in the spinal cord or brain stem, where it causes weakness or even paralysis.