Health officials in Minnesota, USA, said a neurological illness that had struck workers at a pork processing plant, two of them seriously enough to require hospital treatment, posed no danger to the public.

The Minnesota Department of Health (MDH) is investigating an outbreak of a neurological illness among 11 workers at Quality Pork Processors Inc (QPP) in Austin. The link to the plant first came to light when plant staff and doctors in the Austin and Rochester areas realized that a pattern of neurological illnesses was affecting a number of people who worked at the plant.

The workers affected started experiencing symptoms in December 2006, and these progressed and persisted up to July 2007. The MDH started to investigate the cluster about a month ago when it was contacted about the link to the plant.

State health officials began reviewing clinical records, interviewing workers and inspecting the plant straight away to assess potential exposures.

The symptoms take several weeks to months to emerge fully, and are described as abnormal sensations and muscle weakness, which in some cases has been severe. Two people had to go to hospital, with one person requiring extended care and rehabilitation.

The condition appears to be an inflammatory neuroligical illness, with five of the 11 cases having symptoms very like chronic inflammatory demyelinating polyneuropathy,a condition where the immune system gradually destroys the protective sheath around nerve fibres causing failure in nerve signalling, characterized by tingling, numbness, pain, fatigue, and progressive loss of muscle function, among other things.

QPP is said to be fully cooperating with the investigation, which is still ongoing, said MDH in a prepared statement.

The ongoing investigation includes further interviews with affected and non-affected workers, looking through the clinical records, taking samples, and reassessing potential exposures. So far, no specific cause has been found.

All the affected workers, including those who needed hospital treatment, are in recovery or rehabilitation, and there have been no deaths, said the MDH.

Dr Sanne Magnan, Commissioner of Health for Minnesota, said that:

“All of the information we have to date indicates that the general public is not at increased risk for developing this type of illness.”

“Also, there is no evidence that the food supply has been affected,” added Magnan.

The people affected all work in a part of the pork plant where pigs’ heads or organs are processed, and so far the investigation has found no reason to link the workers outside of the workplace.

State epidemiologist for MDH, Dr Ruth Lynfield, said this was a very unusual event, and that:

“We are working very hard together with QPP and many partners in public health, environmental health, medicine, veterinary medicine, agriculture, and the swine industry to determine the cause.”

The meat company has changed working practices as a precaution, following advice from state health officials, said the MDH statement. While the MDH statement did not give details of the changes, Kelly Wadding, the owner and chief executive of Quality Pork told the New York Times that the workers had been given more protective clothing and had stopped using compressed air to remove the brains from the pigs’ heads.

In the meantime, state health officials have linked up with federal agencies such as the US Centers for Disease Control and Prevention (CDC) to spread the information to other colleagues and find out if any similar events have occurred in pork plants elsewhere in the country.

Click here for Minnesota Department of Health (MDH).

Written by: Catharine Paddock