People in the United States are sickened by their food once a year, on average. But the food poisoning that suddenly appeared in White City, Ore., in December 1981 was something else.
It was terrifying, and dramatic, and it seemed to have no cause. In the end, however, that mini-epidemic turned out to be the first show of force by a new strain of bacteria that is now infesting the food supply, infecting as many as 20,000 Americans a year and killing 500.
This is a scientific detective story about those bacteria, known as E. coli O157:H7. It is a story that is continuing and that, in the end, may lead to sweeping changes in the way food is regulated in the United States.
The bacteria that puzzled scientists 16 years ago have turned up in some of the most notorious food poisoning episodes in recent history, including one involving Jack in the Box restaurants in the Northwest in 1993 where four children died after eating hamburgers and hundreds of people became ill.
The bacteria surfaced in 1996 in cases traced to contaminated apple juice and lettuce, then dominated headlines last August when 17 people in Colorado got sick after eating hamburgers from beef processed by a Hudson Foods plant in Nebraska. Hudson, based in Rogers, Ark., recalled 25 million pounds of its ground beef, the largest meat recall in history, and the plant closed its doors.
Normally, Escherichia coli bacteria live innocuously in the intestines of people and animals. But the new E. coli strain can cause diseases from standard diarrhea to kidney failure and death. The bacteria still befuddle medical doctors, who have misdiagnosed their infections as everything from appendicitis to blocked blood vessels of the colon.
Once someone is infected, there is no effective medical treatment to combat the disease, and all doctors can do is prevent dehydration, wait for the disease to run its course, and hope for the best.
''I say the 'E' in E. coli stands for evil,'' said Nancy Donley, a Chicago mother whose son, Alexander, died in 1993 from an E. coli O157:H7 infection.
In just four days, it ''destroyed all of Alex's internal organs and liquefied parts of his brain,'' Mrs. Donley said. It is, she added, ''a terrible, terrible bug.''
At a Meat Plant, The Smoking Gun
The search for the killer strain of E. coli began when about a dozen people showed up one week in December 1981 in the emergency rooms of White City, a working-class city near the California border. The patients described terrifying symptoms: diarrhea attacks occurring several times an hour accompanied by abdominal cramps that women said were worse than labor pains and men said felt like a hot sheet of metal had been placed on their abdomen. At first, the patients said, they had watery stools, but within hours, their diarrhea looked like pure, bright red blood. And it lasted for days.
White City doctors tested patients' stools for a long list of bacteria and parasites, but could not find a culprit. It was not even clear whether the disease was caused by an infectious organism, like a bacterium or a virus, or whether it was due to a toxic chemical. Finally, on a cold damp day in February 1982, frustrated officials of the Oregon public health department called in Dr. Lee Riley, who had recently begun work as a medical detective for the Centers for Disease Control and Prevention in Atlanta, and who is now a professor of infectious disease and epidemiology at the University of California at Berkeley.
Dr. Riley immediately flew to White City. ''We figured that whatever we were dealing with had to be completely new,'' he said.
The first question Dr. Riley tackled was, What did the patients have in common that their friends, family members and neighbors did not? One clue was that they had eaten at a local McDonald's restaurant.
Still, the association might have been purely coincidental. And if the source was McDonald's food, it was not certain what item was causing the illness. The hamburgers? Unlikely, Dr. Riley reasoned. The meat patties were cooked at such a high temperature, he said, that ''we couldn't believe that that kind of cooking would allow a microorganism to survive.''
While Dr. Riley dissected the Oregon cases, the disease struck again, this time in Michigan in May 1982. Again, the patients had just eaten at a McDonald's restaurant.
At the same time, working on the mystery disease at the disease control centers, Dr. Joy Wells, a microbiologist, noticed something suspicious. Nine of the 12 patients whose stools were obtained at the start of the illness contained a type of E. coli designated O157:H7, a label based on the proteins found on the surface of that strain. When the stool of healthy people was tested for comparison, the strain was absent. But the medical investigators were leery.
''We just didn't think E. coli could do something like that,'' Dr. Riley said. It was possible that E. coli O157:H7 was a perfectly harmless bacterium that just happened, by chance, to be in those patients' stools.