Polio is a disease caused by poliovirus. It is a highly infectious disease that attacks the nervous system and can cause complete paralysis in just a matter of hours after infection. It was once believed that the virus had been effectively wiped out through vaccination, but recent cases of the virus have been discovered in both Asia and Africa.

Symptoms of Polio

Young children are most at risk for contracting the polio virus, but it can infect people of any age. In fact, one of the most famous polio sufferers, Franklin Delano Roosevelt, was well into adulthood and had fathered six children before he was infected with the virus.

The polio virus enters the mouth and then passes immediately to the intestines. The initial symptoms of polio are flu-like symptoms including fever, fatigue, headaches, stiffness in the neck, and pain in the limbs. Vomiting, which is not a flu symptom, may also be present (vomiting is a sign that the person is not sick with influenza and something more severe is wrong). One in two hundred cases of polio end with paralysis, usually in the legs. Paralysis can also affect the lungs and respiratory system, making the breathing muscles immobile. However, many people infected with the polio virus never know they have been infected because they show no symptoms. Even without symptoms, the person infected with polio is highly contagious. It is for this very reason that during its worst epidemic years polio was spread so rampantly.

How Polio Is Spread

Polio is spread from person-to-person contact. The virus often enters the environment through feces, and in countries where there is poor hygiene or sanitation measures, the virus is passed along. The polio virus can also be carried by people who have been vaccinated. Although vaccinated people will not see the virus turn into the disease, they can carry it in their intestines and into their feces. Polio can infect hundreds of people before a single person shows symptoms; therefore, World Health Organization considers one diagnosed case of polio to be an epidemic.

There is no cure for polio. Full immunization for polio can prevent the virus from turning into the disease.