The workers at the Quality Pork Processors plant in Austin, Minn., became ill between last December and July with a neurological disorder, the Star Tribune reported Tuesday. The cause remains unknown for chronic inflammatory demyelinating polyneuropathy, which normally affects two people per 100,000.

State health officials stressed they have no evidence indicating the public is at risk or the food supply was affected.

"All of the information we have to date indicates that the general public is not at increased risk for developing this type of illness," Health Commissioner Sanne Magnan said.

With this particular disease, something triggers the immune system to attack the protective sheath enclosing the nerves, Suraj Muley, a University of the Minnesota associate professor and disease expert, told the Star Tribune.

In the pork processing plant workers' case, "the question is whether the animal might harbor bacteria or a virus that triggered it," said Muley, who isn't involved in the investigation and suggested the plant be closed until the investigation is complete.