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Polio (Poliomyelitis)

What is polio?

Poliomyelitis, commonly called polio, is an infectious disease. It is caused by 1 of 3 types of poliovirus. Polio is easily spread from person to person. The poliovirus is a virus that can cause paralysis. But, most people who are infected with polio have no symptoms and a few have mild symptoms. Very few people who get polio develop paralysis. Since the polio vaccine was invented in 1955, polio has been nearly stamped out. In the U.S. There have been no known cases of polio since 1979.

Poor and developing countries may not have access to the vaccine. Polio is still a concern in these areas, especially for infants and children.

What is the cause of polio?

Polio is caused by 1 of 3 types of the poliovirus. It usually spreads due to contact with infected feces. This often happens from poor hand washing. It can also happen from ingestion of contaminated food or water. It can also be spread when an infected person coughs or sneezes infected droplets into the air. Those infected with the virus can excrete the virus in their stool for several weeks. People are most contagious immediately before the onset of symptoms and soon after they appear.

What are the symptoms of polio?

Symptoms of polio vary in their severity. Most affected people have no symptoms at all. This is called an inapparent infection. The other types of polio are abortive, nonparalytic, and paralytic.

The following are the most common symptoms of polios. However, each person may experience symptoms differently.

Abortive polio

Abortive polio is a mild and short course of the disease with one or more of the following symptoms:

  • Fever
  • Decreased appetite
  • Nausea and/or vomiting
  • Sore throat
  • Not feeling well all over (malaise)
  • Constipation
  • Abdominal pain

Nonparalytic polio

The symptoms for nonparalytic polio are similar to abortive polio. The infected person may feel sick for a couple of days then appear to improve before getting sick again with the following symptoms:

  • Pain of the muscles in the neck, trunk, arms, and legs
  • Stiffness in the neck and along the spine

Paralytic polio

The symptoms for paralytic polio are the same as nonparalytic and abortive polio. In addition, the following symptoms may happen:

  • Muscle weakness all over
  • Severe constipation
  • Muscle wasting
  • Weakened breathing
  • Trouble swallowing
  • Muscle paralysis (may be permanent)
  • Drooling

How is polio diagnosed?

Along with a complete physical exam and medical history, the following tests may be done:

  • Cultures of the throat and stool are most commonly used
  • Blood levels or cerebrospinal fluid testing is less commonly used

How is polio treated?


  • How old you are
  • Your overall health and past health
  • How sick you are
  • How well you handle specific medicines, procedures, or therapies
  • How long the condition is expected to last
  • Your opinion or preference

While there is a vaccine for prevention of polio, there is no specific treatment for people who become infected. Treatment is focused on symptom relief. Supportive measures include:

  • Pain relievers, such as acetaminophen or ibuprofen
  • Healthful diet
  • Minimal activity
  • Hot packs or heating pads for muscle pain

What are the complications of polio?

The most severe complication of polio is paralysis. This can lead to problems with breathing, swallowing, and bowel and bladder function.

Post-polio syndrome can happen many years after the initial infection. This syndrome causes muscle weakness and shrinking of the muscles, extreme fatigue, and pain in the muscles and joints.

Can polio be prevented?

Measures to prevent polio include:

  • Good hygiene and hand-washing
  • Immunization


  • 2 months
  • 4 months
  • Between 6 and 18 months
  • Between 4 and 6 years

Vaccines include:

  • IPV. Inactivated poliovirus vaccine is given by a shot (injection). This vaccine is given at all 4 immunization visits. IPV can’t cause polio because the virus has been killed and is safe to use for people with weak immune systems. Tell your healthcare provider if you have an allergy to neomycin, streptomycin, or polymyxin B, as you may not be able to receive the IPV.
  • OPV. Oral poliovirus vaccine is given by mouth. In very rare cases, OPV has been known to cause vaccine-associated paralytic poliomyelitis. It is now recommended that the OPV not be given routinely and that only IPV be given. OPV should NOT be given to anyone with a weak immune system.

Living with polio

Polio can have various effects on your lifestyle, depending on the severity of your symptoms. Types of treatment and support can include:

  • Assistive devices for movement, such as braces, canes, orthotics, and wheelchairs
  • Breathing help, such as extra oxygen or a ventilator
  • Physical and occupational therapy to assist with movement
  • Nutritional therapy, such as special diets or assistance with eating
  • Lifestyle changes to adapt to your symptoms

When should I call my healthcare provider?

If your symptoms get worse or you have new symptoms, let your healthcare provider know. Certain signs and symptoms should be reported immediately, such as:

  • Breathing trouble
  • Swallowing trouble
  • Problems with walking or other types of movement
  • Weakness or extreme fatigue

Key points about polio

  • Polio is an infectious disease caused by any 1 of 3 types of poliovirus. It is easily spread from person to person.
  • Since the introduction of the polio vaccine in 1955, polio in the U.S. has nearly been eliminated.
  • Poor or underdeveloped countries may not have access to the vaccine. Polio is still a concern, especially for infants and children.
  • While there is prevention of the polio, there is no specific treatment for infected people.

Next steps


  • Before your visit, write down questions you want answered.
  • Ask if your condition can be treated in other ways.

Medical Reviewers:

  • Lentnek, Arnold, MD
  • Sather, Rita, RN