Recent reports from the USA suggest the development of a new occupational disease among swine slaughterhouse workers, called Progressive Inflammatory Neuropathy (PIN). On October 29, 2007, the Minnesota Department of Health (MDH) was notified by a tertiary-care provider of unexplained neurologic illnesses among workers in a swine slaughterhouse (plant A) in southeast Minnesota.
Symptoms among the 12 patients from a plant in Minnesota ranged from acute paralysis to gradually progressive symmetric weakness over periods ranging from 8 to 213 days. Severity ranged from minor weakness and numbness to paralysis predominantly in the lower extremities affecting mobility.
All 12 patients reported either working at or having regular contact with an area where swine heads were processed (known as the head table). A compressed air device was used in the plant to harvest brain tissue from pig heads at the head table. In that area a device was placed into the skull of the pig through the foramen magnum, and the force of the air disrupted the brain material into a liquefied form that made it easier to remove (a technique known as “blowing brains”).
This technique caused generation of small droplets and splatter, possibly including aerosolized brain material, to which workers operating the device and others nearby might have been exposed. A survey of the 25 federally inspected swine slaughterhouses with >500 employees in the United States indicated that only three plants (plant A in Minnesota and plants in Nebraska and Indiana) reported recent use of compressed air to extract pig brains.
One hypothesis for development of PIN is that worker exposure to aerosolized pig neural protein might have induced an autoimmune-mediated peripheral neuropathy. Clinicians should provide CDC with information regarding swine slaughterhouse workers who might have illnesses similar to PIN, including patients with peripheral neuropathy, myelopathy, or features of both.
Learn more:
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Samson K. Alert to neurologists-help needed to help solve mysterious neurological illness at Minnesota Pork Plant. Neurology Today. February 1, 2008
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CDC MMWR Investigation of progressive inflammatory neuropathy among swine slaughterhouse workers Minnesota, 2007-2008. January 31,2008 /57
