most wanted virus

polio definition

polio is a contagious viral illness. that in its most severe form causes difficulty breathing and sometimes death. in the U.S the last case of polio happened in 1979. today poliovirus still affects children and adults in places like Afghanistan, Pakistan and Africa. the center for decease control and prevention advises taking proaction if your traveling anywhere there is a risk of polio. poliovirus infects human cells by