a disease is considered as rare disease if
Rare disease In the United States, the Rare Diseases Act of 2002 defines rare disease strictly according to prevalence, specifically "any disease or condition that affects fewer than 200,000 people in the United States",[3] or about 1 in 1,500 people. This definition is essentially the same as that of the Orphan Drug Act of 1983, a federal law that was written to encourage research into rare diseases and possible cures.
History of poliomyelitis The symptoms of poliomyelitis have been described by many names. In the early nineteenth century the disease was known variously as: Dental Paralysis, Infantile Spinal Paralysis, Essential Paralysis of Children, Regressive Paralysis, Myelitis of the Anterior Horns, Tephromyelitis (from the Greek tephros, meaning "ash-gray") and Paralysis of the Morning.[9] In 1789 the first clinical description of poliomyelitis was provided by the British physician Michael Underwood—he refers to polio as "a debility of the lower extremities".[10] The first medical report on poliomyelitis was by Jakob Heine, in 1840; he called the disease Lähmungszustände der unteren Extremitäten ("Paralysis of the lower Extremities").[11] Karl Oskar Medin was the first to empirically study a poliomyelitis epidemic in 1890.[12] This work, and the prior classification by Heine, led to the disease being known as Heine-Medin disease.