This disease is caused by a RNA virus.The polio virus is the smallest known virus.This virus can be affected either through nasal membrane to the olfactory nerves or through food or water.This virus multiplies in the intestine wall and spreads in the body through blood strain. The virus destroys the dorsal horn cells of the spinal cord which controls the activities of the muscles.Without these impulses the fails to work and thus gets shrinks and so the limbs get paralyzed.Thu the patient cannot walk without support.When the respiratory centers of medulla are destroyed by the viruses the breathing fails.this disease is regarded as a disease of infancy and childhood exclusively.Due to these reasons this disease is called infantile paralysis.But now this disease may occur at any stages.It may also spread through contaminated diseases or flies or insects that may contaminate the food.As some symptoms resembles to the same symptoms of fever the diagnosis is not favorable.The incubation period of polio virus is from 7-14 days.The main symptoms are stiffness and pain in the neck and back bone.If the virus enter in  to the Central nervous system causes varying degrees of paralysis. immunization is the effective way of preventing polio myelitis.Salk and Sabin had developed vaccine for polio myelitis.The function of this vaccines is to increase an individual resistance and decreases the total number of cases of polio infection.Due to all these reasons there is no specific cure for polio myelitis.Right intake of Polio Vaccine at the right time can prevent polio,so be aware of that and save your child.