Poliomyelitis is a viral disease that can affect nerves and can lead to partial or full paralysis
Polio; Infantile paralysis; Post-polio syndrome
Poliomyelitis is a disease caused by infection with the poliovirus. The virus spreads by:
Direct person-to-person contact
Contact with infected mucus or phlegm from the nose or mouth
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). Most people do not develop symptoms.
- Lack of immunization against polio
- Travel to an area that has experienced a polio outbreak
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 there has been an outbreak of disease. As a result of a massive, global vaccination campaign over the past 20 years, polio exists only in a few countries in Africa and Asia.
There are three basic patterns of polio infection: subclinical infections, nonparalytic, and paralytic. Most people have subclinical infection, and may not have symptoms.
SUBCLINICAL INFECTION SYMPTOMS
People with subclinical polio infection might not have symptoms, or mild 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.
Exams and Tests
The health care provider may find:
Difficulty lifting the head or legs when lying flat on the back
Trouble bending the neck
Cultures of throat washings, stools, or spinal fluid
Spinal tap and examination of the spinal fluid (CSF examination
) using PCR
The goal of treatment is to control symptoms while the infection runs its course as there are no specific treatment for this viral infection.
People with severe cases may need lifesaving measures, especially breathing help.
Symptoms are treated based on their severity. Treatment may include:
Moist heat (heating pads, warm towels) to reduce muscle pain and spasms
Painkillers to reduce headache, muscle pain, and spasms (narcotics are not usually given because they increase the risk of breathing trouble)
Physical therapy, braces or corrective shoes, or orthopedic surgery to help recover muscle strength and function
The outlook depends on the form of the disease (subclinical, or paralytic) and the body area affected. Most of the time, complete recovery is likely if the spinal cord and brain are not involved.
Brain or spinal cord involvement is a medical emergency that may result in paralysis or death (usually from respiratory
Disability is more common than death. Infection that is located high in the spinal cord or in the brain increases the risk of breathing problems.
Post-polio syndrome is a complication that develops in some patients, usually 30 or more years after they are first infected. Muscles that were already weak may get weaker. Weakness may also develop in muscles that were not affected before.
When to Contact a Medical Professional
Call your health care provider if:
Polio immunization (vaccine) effectively prevents poliomyelitis in most people (immunization is over 90% effective).
Modlin JF. Poliovirus. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009:chap 171.
Silver JK. Post-poliomyelitis syndrome. In: Frontera WR, Silver JK, Rizzo Jr TD, eds. Essentials of Physical Medicine and Rehabilitation. 2nd ed. Philadelphia, PA: Saunders Elsevier; 2008:chap 137.
Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.