An illness among workers at pig slaughterhouses had the Centers for Disease Control (CDC) worried, and it has begun investigating the mystery ailment. The new disease has surfaced in 12 of 1,300 employees at the Quality Pork Processors factory near Minneapolis. Patients complain of burning sensations, numbness, and weakness in the arms and legs. For some, walking is difficult and work impossible and, while symptoms have slowly lessened in severity in some, it has not completely disappeared in any of the patients.
The CDC and they are looking into about 25 other large-scale pig slaughterhouses in 13 states to locate other cases. CDC investigators believe they found a few more at an Indiana slaughterhouse, one of only two places other than the Minnesota plant that use compressed air to empty pig skulls. All three establishments have ceased that activity.
The illness is similar to some known conditions, but is not an exact match to any, nor is its cause. The ailment-tentatively being called “progressive inflammatory neuropathy”-resembles Guillain-Barre syndrome, an autoimmune condition that sometimes follows fairly benign infections, particularly those caused by an intestinal bacterium called Campylobacter. In the Minnesota cases no germ is involved. Apparently, the seemingly new illness is a result of inhaling microscopic flecks of pig brain. “This appears to be something new,” Minnesota’s state epidemiologist, Ruth Lynfield, said last week.
Before it closed, the Minnesota packinghouse slaughtered 1,900 pigs a day, working two meat-cutting shifts and one clean-up shift. Virtually every part of the pig was used, including ears, entrails, and bone. The 12 Quality Pork workers stricken with the neurological illness are mostly Hispanic immigrants and all work at or near the “head table” where the animals’ severed heads are processed. One of the steps in the process involves removing the pigs’ brains with compressed air forced into the skull through the spinal cord entrance. Brains are then packed and sent to markets in Korea and China as food.
Investigators do not believe the meat was contaminated and have theorized that the harvesting technique-“blowing brains” on the floor-produces aerosols of brain matter. Once the matter is inhaled, the body’s immune system produces antibodies that attack the brain compounds. Apparently, the antibodies also attack the body’s own nerve tissue because of its similarity to that of the pig.
In November 2006, a worker came down with fever, malaise and rapidly progressing weakness. When he was admitted to a Rochester hospital he was unable to walk. Weeks, or possibly months before, he was assigned the job of “blowing brains” on one of the shifts. Like many of the subsequent patients, he had evidence in his bloodstream and spinal fluid of inflammation and was given high-dose intravenous steroids, as is common for similar conditions. Over the course of a few months he regained most of his function, but the cause of the problem remained unknown. In April, he returned to work at the head table. Within two months, he developed widespread pain and sensation or weakness. He was taken off work in June and recovered over the summer, returning to the plant in September. By November, his painful symptoms returned.