Doctors at the Mayo Clinic and government public health experts have confirmed the mysterious illnesses in 24 slaughterhouse workers in Minnesota and Indiana from 2006 to 2008 was caused by an autoimmune response to a mist of pig brain tissue.
Their article was published Monday in the British medical journal Lancet Neurology. Mayo Clinic neurologist Dr. Daniel Lachance, the lead author, said it was the first comprehensive account of the outbreak and response from Mayo, the state Health Department and the Centers for Disease Control and Prevention.
"This was really a kind of unique experiment of nature where an unusual form of harvesting a part of an animal was utilized and inadvertently exposed individuals through their respiratory tract or their eyes or mouth and ended up triggering an autoimmune response in their own bodies," he said.
ABC News by Chris Williams, AP, 12/1/09