The first person to detect a faint signal in all the noise was the interpreter.
The 33-year-old woman who worked for eight years with Spanish-speaking patients at a clinic in southern Minnesota noticed something familiar as she translated the story of a young meatpacker last September.
She had heard a version of it from two other workers at the same slaughterhouse and had told it to their doctors.
The interpreter's insight set in motion a story, still unfolding, that may be making envious the ghost of Berton Roueche, the legendary chronicler of medical mysteries at New Yorker magazine. A new disease has surfaced in 12 people among the 1,300 employees at the factory run by Quality Pork Processors, about 100 miles south of Minneapolis.
The ailment is characterized by sensations of burning, numbness and weakness in the arms and legs. For most, this is unpleasant but not disabling. For a few, the ailment has made walking difficult and work impossible. The symptoms have lessened in severity, but in none of the sufferers have they disappeared.
While the illness is similar to known conditions, it does not match any exactly. Nor is the leading theory of its cause something researchers have studied. That is because the illness appears to be caused by inhaling microscopic flecks of pig brain.
"This appears to be something new," said Minnesota's state epidemiologist, Ruth Lynfield.
The packing house in Austin, Minn., slaughters 1,900 pigs a day. Virtually everything is used, including ears, entrails and bone. The 12 sufferers of the neurological illness - most are Hispanic immigrants - all work at or near the "head table" where the animals' heads are processed.
One of the steps in that operation involves removing the pigs' brains with compressed air. The brains are packed and sent to Korea and China as food.
Investigators say there is no reason to suspect the pork was contaminated. Their hypothesis is that the harvesting technique - known as "blowing brains" - produces aerosols of brain matter. Once inhaled, the immune system is prompted to produce antibodies that attack the pig brain compounds, but may also attack the body's own nerve tissue because it is so similar.
If this theory is correct, the ailment - for the moment called "progressive inflammatory neuropathy" - resembles Guillain-Barre syndrome, an autoimmune condition that sometimes follows fairly benign infections. The theory makes enough sense that the Centers for Disease Control and Prevention is looking into about 25 other pig slaughterhouses in 13 states, seeking other cases.
Investigators believe they found a few at an Indiana slaughterhouse, one of only two places other than the Minnesota packing plant that uses compressed air to empty pig skulls. All three have ceased that activity.
Studies are under way that may shed light on the biological mechanisms of the illness. A harder question may be: Why now?
Kelly Wadding, 55, started as a floor worker in 1970 and now owns the company, says the company has harvested brains since 1998, using the same method and the same air hose.
"That is the million-dollar question," he said.