Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Polio and Post-Polio Syndrome ?
    ### Response:
    Polio is an infectious disease caused by a virus. The virus lives in an infected person's throat and intestines. It is most often spread by contact with the stool of an infected person. You can also get it from droplets if an infected person sneezes or coughs.
    