MINNEAPOLIS (AP) — State health officials said Monday they were investigating neurological illnesses among 11 workers at a pork processing plant, but that there was no evidence that the public was at risk.
Health Commissioner Dr. Sanne Magnan also said there was no evidence that the food coming out of Quality Pork Processing in Austin has been contaminated.
The workers who became ill had symptoms such as numbness, and tingling in their arms and legs.
Two were hospitalized for a time. Some of the workers recovered completely, while others are still going through rehabilitation, she said.
Five of the workers had symptoms consistent with chronic inflammatory demyelinating polyneuropathy, a condition characterized by progressive weakness and impaired sensory functions in legs and arms. It is treated with steroids and immunosuppressant drugs, according to the National Institutes of Health.
The patients included men and women from a range of ages and ethnicities, said State Epidemiologist Ruth Lynfield. But they all worked in the same part of the plant, removing hog brains with compressed air.
None of the plant's other 1,300 workers reported similar symptoms, and there have been no similar reports at Minnesota's other large hog slaughterhouse in Worthington, officials said.
Quality Pork owner and CEO Kelly Wadding said workers who butcher the hog heads have been given more protective clothing and no longer use compressed air to remove brains.
He said Quality Pork's production levels have not been reduced because of the illnesses.
Hormel Foods Corp., which is based in Austin, is Quality Pork's main customer.
Staff nurses at Quality Pork noticed the first symptoms in December 2006, and a total of 10 cases had come in through July, Magnan said.
Doctors in Austin, about 90 miles south of Minneapolis, and at Mayo Clinic in Rochester tried to determine what was making the workers sick.
Mayo reported the matter to the state Health Department in late October, Lynfield said.
She said the symptoms are not consistent with a repetitive stress injury or with the family of diseases that include mad cow disease or scrapie in sheep, which are linked to proteins called prions.
But while those diseases cause irreversible brain deterioration, most of the workers in Austin have recovered. ''That's not something you expect with a prion disease,'' she said.