Poliomyelitis is a viral infection of the gut which can cause motor nerve paralysis.

Poliomyelitis ("polio"), or infantile paralysis, is a viral paralytic disease. The causative agent, a virus called poliovirus (PV), enters the body orally, infecting the intestinal lining. It may proceed to the blood stream and into the central nervous system causing muscle weakness and often paralysis. Polio is a communicable disease which is categorized as a disease of civilization. Polio spreads through human-to-human contact, usually entering the body through the mouth due to fecally contaminated water or food. The poliovirus is a small RNA (ribonucleic acid) virus that has three different strains and is extremely infectious. The virus invades the nervous system, and the onset of paralysis can occur in a matter of hours. While Polio can strike a person at any age, over fifty percent of the cases occurred to children between the ages of three to five. The incubation period of polio, from the time of first exposure to first symptoms, is from three to thirty five days. Most people infected with the poliovirus have no symptoms or outward signs of the illness and are thus never aware they have been infected. After the person is exposed to the poliovirus, the virus is expelled through faeces for several weeks and it is during this time that a polio outbreak can occur in a community. The three strains of poliovirus result in non-paralytic polio, paralytic polio, and bulbar polio. In all forms of polio, the early symptoms of infection are fatigue, fever, vomiting, headache, pain in the neck and extremities. http://en.wikipedia.org/wiki/Poliomyelitis