About Polio Virus Symptoms

Overview

The polio virus causes an illness called poliomyelitis. The wild-type polio virus has been eradicated from the United States, and its incidence is also decreasing around the world, thanks to aggressive vaccination programs. There have been no wild-type polio infections in the United States for 40 years.

Considerations

Polio is transmitted from humans to humans via droplets, or with contact with stool from someone infected with the virus. This happens in locations with poor hygienic conditions. Most cases of polio infection are asymptomatic or cause a minor illness with fever and sore throat.

Types

The most commonly recognized symptom of polio is called flaccid paralysis with arreflexia. This means that the extremities are paralyzed, with loss of muscle tone and reflexes. This paralysis is rapid in its progress, may happen in just one side of the body, and can affect the respiratory muscles. Patients also complain of muscle aches and spasms. The involvement of the respiratory muscles may lead to death if breathing is not supported medically. Paralysis usually occurs several days to weeks after the initial symptoms. Symptoms begin to improve after the fever goes away.

Effects

Most patients with paralysis caused by polio recover after several days, and most have return of full muscle strength and function, although some patients will have permanent deficits, particularly if they still have symptoms a year after the onset of the illness.

Warning

Adult patients can have recurrence of the symptoms decades after their initial illness. This is called noninfectious, post-polio syndrome. Patients with post-polio syndrome suffer from severe pain, worsening of remaining weakness, or new weakness of their muscles.

Prevention/Solution

Vaccination has eradicated wild-type polio in the United States. There are two vaccines: an oral live-virus vaccine and an inactivated-virus vaccine, given as a shot. The oral vaccine can rarely produce symptoms similar to polio infection. This happens mostly in children with deficiencies in their immune systems.