(AP) - Minnesota health officials are testing more than 100 workers at a pork processing plant in Austin where a dozen have come down with a mysterious neurological ailment.
Authorities also said Friday that they have ruled out chemical toxins as the cause of the illness.
The 12 workers who show signs of nerve inflammation all worked at the head table, where they cut meat off hogs' heads and blasted compressed air into the skulls to remove the brains. Their symptoms include muscle weakness and tingling and numbness in the legs and arms.
The working theory is that the sick workers were exposed to something in the brain tissue that triggered their immune systems to attack their own bodies.
The Health Department said it has interviewed about 120 employees, both from the head table and from other parts of the Quality Pork Processors plant.
More than 100 agreed to throat swabs and blood draws, and the agency is examining those specimens for any signs of an infection.
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