Poliomyelitis (Polio)

What is poliomyelitis?

Poliomyelitis, also called polio, is a highly contagious infectious disease caused by three types of poliovirus. The poliovirus is a virus most recognized for its destruction to the nervous system causing paralysis. The majority of individuals who are infected with polio, however, have no symptoms and few have mild symptoms. Of those persons that do acquire the infection, 5 percent or fewer may develop paralytic disease. Since the advent of the polio vaccine during the early 1950s, infections from the poliovirus have nearly been eradicated. 

In countries that are poor, underdeveloped, and do not have access to the vaccine, polio is still a concern especially for infants and children. The World Health Organization (WHO) continues its efforts to eradicate the virus worldwide.

• The last case of naturally occurring polio infection in the US was in 1979.
• Infants and young children are at greatest risk.
• Poliovirus infections are more common during the summer and autumn seasons.
• The risk for paralysis from the virus increases with age.

How is poliovirus spread?

Transmission of the poliovirus most often occurs from fecal-oral contact. Usually, this occurs from poor hand washing or from ingestion of contaminated food or water. Respiratory secretions also spread poliovirus. Those infected with the virus can excrete the virus in their stool for several weeks. Individuals are most contagious immediately before the onset of symptoms and soon after they appear.

What are the symptoms of poliomyelitis?

Poliovirus infections can exhibit symptoms in varying degrees of severity. The majority of individuals (90 to 95 percent) have no symptoms at all. This is referred to as inapparent infection. Three other categories of polio infection will be discussed.

The following are the most common symptoms of poliomyelitis. However, each child may experience symptoms differently. Symptoms may include:

• abortive poliomyelitis - a mild and short course of the disease with one or more symptoms including fever (up to 103° F); decreased appetite; nausea and/or vomiting; sore throat; malaise (not feeling well); constipation; or abdominal pain.
• nonparalytic poliomyelitis - the symptoms of nonparalytic poliomyelitis include the symptoms for abortive poliomyelitis, but the headache, nausea, and vomiting may be worse. In addition, symptoms may include the child feeling sick for a couple of days, and then appear to improve before getting sick again with pain of the muscles in the neck, trunk, arms, and legs, and stiffness in the neck and along the spine.
• paralytic poliomyelitis - the symptoms of paralytic poliomyelitis include the symptoms of nonparalytic and abortive poliomyelitis. In addition, symptoms may include muscle weakness all over; severe constipation; muscle wasting; weakened breathing; difficulty swallowing; weak cough; flushed or blotchy skin; hoarse voice; bladder paralysis; or muscle paralysis.

The symptoms of poliomyelitis may resemble other problems or medical conditions. Always consult your child's physician for a diagnosis.

How is poliomyelitis diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for poliomyelitis may include the following:

• cultures of the throat, urine, and stool
• lumbar puncture (spinal tap) - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. 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. CSF is the fluid that bathes your child's brain and spinal cord.
• history of the child not receiving the polio vaccine or not completing the series of polio vaccines

Treatment for poliomyelitis:

Specific treatment for poliomyelitis will be determined by your child's physician based on:

• your child's age, overall health, and medical history
• extent of the disease
• your child's tolerance for specific medications, procedures, or therapies
• expectations for the course of the disease
• your opinion or preference

While there is prevention of the poliovirus, there is no cure for children who become infected. Treatment is supportive. This means that the symptoms may be treated to improve your child's comfort and recovery. Treatment may include:

• treatment of pain with analgesics (such as acetaminophen)
• bed 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)

Complications of paralytic poliomyelitis may include permanent paralysis of certain muscle groups including breathing muscles and leg muscles.

How can poliomyelitis from the virus be prevented?

The following prevention measures will help prevent the spread of the poliovirus:

• proper hygiene and hand washing techniques
• immunization against poliovirus
  In the US, the polio vaccine is recommended to be given at the following ages:
  • 2 months
  • 4 months
  • between 6 and 18 months
  • between 4 and 6 years
  
  Two versions of the vaccine may be administered:
  • IPV
    Inactivated polio vaccine (IPV) is administered by injection (a shot). This vaccine is administered at all four immunization visits. Administration of the IPV cannot cause polio and is safe to use for individuals with weakened immune systems.
  • OPV
    Oral polio vaccine (OPV) is administered by mouth. In rare cases, OPV has been known to cause vaccine-associated paralytic poliomyelitis (VAPP). As of January 2000, the Centers for Disease Control and Prevention (CDC), Advisory Committee on Immunization Practices (ACIP), and American Academy of Pediatrics(AAP) has recommended that the OPV not be given routinely and that only IPV be given. There are situations when it may be necessary for your child to receive OPV, such as travel to countries where infectious, or "wild," poliovirus may be communicable.
    
    OPV should NOT be given to your child if they have any of the following:
    • a weakened immune systems
    • are taking long-term steroids
    • cancer
    • AIDS or HIV infection
    • allergies to neomycin, streptomycin, or polymyxin B

  Always consult your child's physician regarding vaccines.

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