Article (Transfusion -- March 8, 2012): The United States Trypanosoma cruzi Infection Study: Evidence for Vector-borne Transmission of the Parasite That Causes Chagas Disease Among United States Blood Donors.
The ALS Association says the average lifespan of someone diagnosed with the condition is between two and five years. More than 50 percent make it past year three. Twenty percent make it past year five. From there, the number plummets. Less than 5 percent make it past two decades.
ALS is extremely rare, affecting only about two out of every 100,000 people, according to the ALS Association [source: ALSA]. About 5,600 people are diagnosed with the disease in the U.S. each year, and between 20,000 and 30,000 people live with it at any one time [source: ALSA]. What exactly causes ALS isnât known, but researchers are learning more about the disease all the time. In most cases (90 to 95 percent), there is no known cause, and the disease is called sporadic ALS. In the remaining cases (5 to 10 percent), the disease is passed down through families, and is called familial ALS.