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Alternative Names Return to topPolio; Infantile paralysis
Definition Return to top
Poliomyelitis is a viral disease that can affect nerves and lead to paralysis.
Causes Return to top
Poliomyelitis is a disease caused by infection with the poliovirus. The virus spreads by direct person-to-person contact, by contact with infected mucus or phlegm from the nose or mouth, or by contact with infected feces.
The virus enters through the mouth and nose, multiplies in the throat and intestinal tract, and then is absorbed and spread through the blood and lymph system. The time from being infected with the virus to developing symptoms of disease (incubation) ranges from 5 - 35 days (average 7 - 14 days).
In areas where there is an outbreak, those most likely to get the disease include children, pregnant women, and the elderly. The disease is more common in the summer and fall.
Between 1840 and the 1950s, polio was a worldwide epidemic. Since the development of polio vaccines, the incidence of the disease has been greatly reduced. Polio has been wiped out in a number of countries. There have been very few cases of polio in the Western hemisphere since the late 1970s. Children in the United States are now routinely vaccinated against the disease.
Outbreaks still occur in the developed world, usually in groups of people who have not been vaccinated. Polio often occurs after someone travels to a region where the disease is common. Thanks to a massive global campaign over the past 20 years, polio exists only in a few countries in Africa and Asia.
Symptoms Return to top
There are three basic patterns of polio infection: subclinical infections, nonparalytic, and paralytic. Approximately 95% of infections are subclinical infections, which may not have symptoms.
People with subclinical polio infection might not have symptoms, or their symptoms may last 72 hours or less.
Clinical poliomyelitis affects the central nervous system (brain and spinal cord), and is divided into nonparalytic and paralytic forms. It may occur after recovery from a subclinical infection.
Symptoms usually last 1 - 2 weeks.
Exams and Tests Return to top
The health care provider may find signs of meningeal irritation (similar to meningitis), such as stiff neck or back stiffness with difficulty bending the neck. The person also might have difficulty lifting the head or lifting the legs when lying flat on the back, and abnormal reflexes.
Treatment Return to top
The goal of treatment is to control symptoms while the infection runs its course.
People with severe cases may need lifesaving measures, especially breathing help.
Symptoms are treated based on how severe they are. Treatments include:
Outlook (Prognosis) Return to top
The outcome of the disease depends on the form (subclinical, nonparalytic, or paralytic) and the site affected. If the spinal cord and brain are not affected, which is the case more than 90% of the time, complete recovery is likely.
Brain or spinal cord involvement is a medical emergency that may result in paralysis or death (usually from respiratory difficulties).
Disability is more common than death. Infection high in the spinal cord or in the brain increases the risk of breathing problems.
Possible Complications Return to top
When to Contact a Medical Professional Return to top
Call your health care provider if:
Prevention Return to top
Polio immunization (vaccine) effectively prevents poliomyelitis in most people (immunization is over 90% effective).Update Date: 1/22/2008 Updated by: Kenneth M. Wener, MD, Department of Infectious Diseases, Lahey Clinic, Burlington, MA. Review provided by VeriMed Healthcare Network.