Poliomyelitis, commonly known as polio, is a viral infection which can lead to a range of symptoms of varying seriousness. Infections are generally classified as non-paralytic or paralytic, and the exact effects of polio vary by infection type. Non-paralytic polio may cause only mild, flu-like symptoms, or may even be symptom-free. The much rarer paralytic polio can lead to partial or full paralysis of the face, limbs, or breathing muscles, and may in some cases prove fatal. Occasionally, individuals who were formerly infected with polio may experience post-polio syndrome, or the onset of polio-like symptoms which occurs years or even decades after initial infection.
The effects of polio infections which are classified as non-paralytic tend to be relatively mild, and may be similar to the symptoms of influenza. These symptoms may include nausea, vomiting, fever, sore throat, headache, and muscle stiffness. Generally, non-paralytic polio infections tend to work their way through the body in one to two weeks. In some cases, symptoms may be so mild that the infected person is not aware of the infection.
Conversely, the effects of polio infections classified as paralytic can be quite serious or even fatal. This form of polio attacks the nerves of the spine or the brain stem. As a result, infected persons might experience partial or full paralysis of the limbs, the face, the breathing muscles, and the heart. It should be noted, however, that paralytic polio is quite rare, accounting for only about 1 percent of all polio infections.
Less severe cases of paralytic polio may cause muscle damage that is reversible. Patients in these instances may recover full use of their muscles following intervention by physical therapy or assistive breathing devices. Severe cases, however, may lead to permanent paralysis of the limbs, breathing muscles, or heart, which may in turn prove fatal.
In some cases, persons formerly infected with polio may experience what is known as post-polio syndrome, or the emergence of symptoms which closely resemble the effects of polio years or even decades after initial infection. The symptoms of post-polio syndrome range in severity from case to case. Generally, however, those with the condition experience fatigue, soreness and weakness in the joints and muscles, and respiratory difficulties.
While the effects of polio can be debilitating or even deadly, it is important to know that through vaccination, this once-common illness has now been eradicated throughout much of the world. Polio continues to strike parts of Asia, the Middle East, and Africa, however. Thus, those traveling to these regions should ensure that they have been properly vaccinated against this virus.