What is Polio?

Polio is a highly contagious disease that is caused by a virus that primarily lives in the intestines and human feces

• The poliovirus is spread from person-to- person primarily through oral contact with the feces of an infected person (for example, by changing diapers); it can also spread through contaminated food or water, especially in areas with poor sanitation systems. There have also been cases that have been transmitted by direct oral contact or by droplet spread
• Once inside the body, the poliovirus multiplies in the throat and intestinal tract, then travels through the bloodstream where it infects the brain and spinal cord
• Paralysis occurs because the poliovirus attacks the nervous system and damages or destroys the nerves that send messages between the brain and the muscles
  

What are the sign and symptoms of Polio?

Although polio has the ability to cause paralysis and death, most people who are infected with the poliovirus don’t get sick, but these people can still spread the virus to others. Of those who do contract polio, a small subset will develop either nonparalytic or paralytic polio.

Nonparalytic polio—A small number of infected people develop this type of polio

• This form of the disease doesn’t lead to paralysis; symptoms can include: sore throat, fever, nausea, vomiting, constipation, or diarrhea; most people recover within a week
• Nonparalytic aseptic meningitis (an infection of the outer covering of the brain) is another type of nonparalytic polio that causes stiffness of the neck, back, and/or legs in addition to the flu-like symptoms mentioned above; these symptoms generally last from 2 to 10 days, followed by a complete recovery

Paralytic polio—Less than 1% of infected people develop paralytic polio

• This is the most serious form of the disease; it can be fatal without respiratory support
• Paralytic polio often begins with a fever; other symptoms, including headache, neck and back stiffness, and constipation, generally appear a few days later
• Acute flaccid paralysis, which causes the limbs to appear loose and floppy, often comes on suddenly and usually affects only one side; if both sides are affected, typically one side is worse than the other

Post-polio syndrome

• 30 or 40 years after recovery, 25% to 40% of adults who had polio as children experience muscle weakness and pain in the limbs that were previously affected by polio, or they develop new weakness or paralysisOther signs and symptoms may include fatigue and exhaustion with minimal activity, breathing or swallowing problems, sleep-related breathing disorders (for example, sleep apnea), and/or decreased tolerance of cold temperatures
  

What are the potential complications of Polio?

Polio can lead to muscle paralysis that results in deformities of the hips, ankles, and feet. Although many of the deformities can be corrected with surgery and physical therapy, these treatments often aren’t available options in the developing countries where polio still exists.

Other complications associated with the prolonged hospital stay as a result of the paralysis caused by polio infection involve the lungs, kidneys, and heart:

• Pulmonary edema—A potentially life-threatening condition that fills the lungs with fluid and prevents them from absorbing oxygen
• Aspiration pneumonia—An inflammation of the lungs that is caused by inhaling stomach contents into the lungs
• Urinary tract infections—Bacterial infections that can permanently damage the kidneys if not treated promptly
• Kidney stones—Usually form when urine becomes too concentrated; they may cause ongoing urinary tract infections or kidney damage
• Intestinal obstruction—A partial or complete blockage of the bowel that prevents
  food from moving through the intestinal tract; severe obstructions can lead to potentially life-threatening complications
• Myocarditis—An inflammation of the thick muscular layer of the heart that can
  lead to chest pain, an abnormal heartbeat, or congestive heart failure; it can also cause blood clots to form, which greatly increases the risk of stroke
• Cor pulmonale—A heart condition that occurs when the right side of the heart
  can’t pump hard enough to compensate for prolonged high blood pressure in the arteries and veins in the lungs
  

How is Polio treated?

Past Treatment Options

In 1916, a large polio outbreak in the United Stated spurred researchers to find treatments for the disease. What resulted was one of the most recognized symbols of polio’s long and difficult history.

The iron lung—About the size and weight of a small car, the iron lung was a sealed chamber with an electrically driven bellows that regulated breathing. People with polio were encased in the metal chambers for months, years, and sometimes for life.

A number of other therapies, including rigid braces and body casts, were also tried
in an effort to prevent deformities. However, these treatments often did more harm than good.

Then in the 1940s, an Australian army nurse—Sister Elizabeth Kenny—began treating afflicted limbs with massage, exercise, and warm, moist heat. While Kenny’s therapy could improve mobility, it could not reverse permanent paralysis.


Current Treatment Options

Because no cure for polio exists, the focus is on increasing comfort, speeding recovery, and preventing complications. Today, supportive treatments for polio include:

• Antibiotics for secondary infection
• Analgesics for pain
• Portable ventilators for breathing
• Moderate exercise
• A nutritious diet
  

How do you prevent Polio?

Vaccination is the best way to prevent polio.
Children
Today, most children in the US receive 4 doses (injections) of inactivated polio vaccine (IPV) according to the following schedule:

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

IPV is 90% effective after 2 doses and 99% effective after 3 doses. Because the vaccine contains inactivated (killed) poliovirus, it cannot cause polio. The most common side effects are pain, swelling, or redness at the injection site; fever, loss of appetite, fussiness and drowsiness.

Adults

Most adults do not need the polio vaccine because they were vaccinated as children. But there are 3 groups of adults who should consider vaccination because they are at higher risk than the general adult population.

• People who are traveling to areas of the world where polio still commonly occurs
  
• Laboratory workers who might handle poliovirus
  
• Health-care workers treating patients who may have polio