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What is polio?

Poliomyelitis, or simply polio, is a highly contagious infectious disease caused by three types of poliovirus. The poliovirus is a virus that destroys nervous system causing paralysis.

  • Since the polio vaccine was invented during the early 1950s, infections from the poliovirus have nearly been eradicated in the United States.
  • The vaccine is given four times.
  • Among those who don't receive the vaccine, infants and young children are at the greatest risk.
  • The most severe form can result in paralysis.
  • There is no cure.

What are the types of polio?

  • Abortive poliomyelitis: The mildest form.
  • Nonparalytic poliomyelitis: Symptoms are more severe than abortive, but not as bad as paralytic.
  • Paralytic poliomyelitis: The most severe; may result in permanent paralysis of certain muscle groups, including breathing muscles and leg muscles.

Is polio common?

Since the advent of the polio vaccine during the early 1950s, infections from the poliovirus have nearly been eradicated. Polio is still a problem in poor, undeveloped countries. Infants and children are at the greatest risk, and infections are most common during summer and fall.

Can polio be prevented?

Yes. In addition to proper hygiene and handwashing techniques, the best way to prevent polio is by being vaccinated. The polio vaccine, or IPV (Inactivated polio vaccine), is recommended four times, when your child is:

  • 2 months old
  • 4 months old
  • Between 6 and 18 months old
  • Between 4 and 6 years old (children 7 to 18 years old may catch up as needed)

Symptoms & Causes

What causes polio?

The poliovirus spreads most often from fecal-oral contact. Usually, this occurs from poor hand washing or from consuming of contaminated food or water. Sneezing or coughing also spreads the virus. Your child is most contagious immediately before any symptoms show up and soon after they appear.

What are the symptoms of polio?

About 90 to 95 percent of people who do get infected with polio have no symptoms at all. Of those who do get the infection, 2 percent or fewer may develop paralytic disease. Symptoms may vary depending on the kind of polio and vary child-to-child.

The most common include:

  • For nonparalytic poliomyelitis
    • Headache, nausea, and vomiting may be worse
    • Child may feel sick for a couple of days, then appear to improve before getting sick again
    • Pain of the muscles in the neck, trunk, arms, and legs
    • Stiffness in the neck and along the spine
  • For paralytic poliomyelitis
    • The symptoms of nonparalytic and abortive poliomyelitis
    • Muscle weakness all over
    • Severe constipation
    • Muscle wasting
    • Weakened breathing
    • Difficulty swallowing
    • Weak cough
    • Flushed or blotchy skin
    • Hoarse voice
    • Bladder paralysis
    • Muscle paralysis

Diagnosis & Treatments

How is polio diagnosed?

In addition to a complete medical history and physical exam, your doctor may want to run a few tests including:

  • Cultures (of the throat, urine, and stool)
  • Lumbar puncture (spinal tap)
    • A special needle is placed into the lower back, into the spinal canal
    • Measures the pressure in the spinal canal and brain
    • A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems
    • Not be recommended if your child is very ill

How is polio treated?

There's no cure for children who become infected with polio. The only thing you can do is to help improve your child's comfort and recovery.

Supportive treatment may include:

  • Acetaminophen for fever or pain
  • Plenty of rest (until fever is reduced)
  • Adequate diet
  • Minimal exertion and exercise
  • Hot packs or heating pads (for muscle pain)
  • Hospitalization (may be required for those individuals who develop paralytic poliomyelitis)

How Boston Children's Hospital approaches polio

The Children's Hospital Informatics Program created HealthMap, an online resource and smart phone app that helps track the spread of contagious diseases in real time, including polio.

Practitioners Who Specialize In This Condition

Colyn Watkins, MD

Colyn Watkins, MD

Orthopedic Surgeon, Orthopedics and Sports Medicine Department
Assistant Professor of Orthopedic Surgery, Harvard Medical School
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