How could people get Mad Cow Disease?
Both classic and variant CJD belong to a broad group of human and animal diseases known as transmissible spongiform encephalopathies (TSEs). The name derives from the spongy holes, visible under a microscope, that develop in affected brain tissue. TSEs in humans One of the oldest known human TSEs is kuru. Found only in a remote New Guinea tribe, kuru reached epidemic proportions in the 1950s and 1960s. How the disease originated isn’t clear, but scientists know that it spread when tribe members ritualistically consumed the brains of dead relatives. Other human TSEs include Gerstmann-Straussler-Scheinker disease and fatal familial insomnia — hereditary diseases so rare they occur in just a few families. TSEs in animals The most widespread TSE in animals is scrapie, a disease that has affected sheep and goats since the mid-18th century. Infected animals become agitated, attempt to rub off their wool by scraping against trees and posts, and usually die a few months after symptoms appear.
