Poliomyelitis is a highly contagious infectious disease. This illness is caused by three types of poliovirus. The poliovirus is a virus most recognized for its destruction to the nervous system causing paralysis. An ancient disease, it was first recognized as a medical entity by Jakob Heine in 1840. Since polio immunization has become widespread, cases of polio are very rare.

Causes

Poliomyelitis is a communicable disease caused by infection with the poliovirus. Transmission of the virus occurs by direct person-to-person contact, by contact with infected secretions from the nose or mouth, or by contact with infected feces. It usually enters the body when the person ingests contaminated food or water, or touches the mouth with contaminated hands.

Besides this small outbreak, there have been very few cases of polio in the Western hemisphere since the late 1970s. This is due to a massive eradication program, which included mass vaccination in these regions. However, there are still areas of the world where polio is widespread. The disease is more common in the summer and fall.

Between 1840 and the 1950s, polio was a worldwide epidemic. Since the development of polio vaccines, the incidence is much reduced. Outbreaks still occur, usually in non-immunized groups.

Symptoms

Symptoms of the disease can start 7-14 days after infection, but usually 7-10 days. Even in people who have not been vaccinated, about 95% of cases of polio are mild, causing a brief, unidentified illness with headache, fever and sometimes vomiting, that lasts for a few days and passes with no ill effects. However, in some cases this stage is followed by a very serious illness.

Once established in the intestines, poliovirus can enter the blood stream and invade the central nervous system spreading along nerve fibres. As it multiplies, the virus destroys nerve cells (motor neurons) which activate muscles. These nerve cells cannot be regenerated and the affected muscles no longer function. The muscles of the legs are affected more often than the arm muscles.

Treatment

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. There must be bed rest during the early course of the illness. Respiratory support with intermittent positive-pressure respiration may be requires if the muscles of respiration are involved. Once the acute phase of the illness has subsided, patient rehabilitation may take place including occupational therapy, physiotherapy and occassionally surgery.