Poliomyelitis is often called Polio or Infantile Paralysis. Polio is the short term condition, with Poliomyelitis being the chronic, long term condition. Polio is an infectious disease caused by a virus that attacks the central nervous system. The virus is taken in by mouth, but further contamination is also possible from the hands. The incubation period of the virus is 7-12 days. The affects of the virus differ in severity from an influenza-like stomach upset to the less common muscle weakness and paralysis of Paralytic Poliomyelitis (can affect breathing - bulbar poliomyelitis). There is very low incidence of the disease in most countries now, as immunization is highly effective, but booster doses are advisable when visiting countries with a high incidence of the disease.