The Centers for Disease Control and Prevention (CDC) continues an on-going investigation into the incidence of neurological disease in processing facility workers in Minnesota and Indiana. The agency has named the disorder progressive inflammatory neuropathy (PIN).
The disorder has affected workers associated with the use of compressed air to remove brain tissue. Officials are investigating the possibility that the disorder may be associated with the inhalation of droplets produced by the tissue removal process. Symptoms have ranged from acute paralysis to gradually progressive symmetric weakness over periods ranging from 8 to 213 days.
Investigators say there is no reason to suspect that either the brains or the pork cuts were contaminated. Their working hypothesis is that the harvesting technique — known as "blowing brains" on the floor — produces aerosols of brain matter. Once inhaled, the material prompts the immune system to produce antibodies that attack the pig brain compounds, but apparently also attack the body’s own nerve tissue because it is so similar.
Nationally, only 3 slaughter facilities utilize this technique to remove brain tissue. All three have discontinued the process until the investigation is complete.