They have only recently been recognized as the cause of several infectious diseases, including mad cow disease and Creutzfeldt-Jakob Disease, which kill by crowding out healthy brain cells.
Hace muy poco que se los ha reconocido como la causa de enfermedades infecciosas graves, incluida la enfermedad de las vacas locas y la de Creutzfeldt-Jacob, que matan al atestar células sanas del cerebro.