A bug that kills children

E. coli 0157:H7 is a mutated version of a bacterium found abundantly in the human digestive system. Most E. coli bacteria help us digest food, synthesize vitamins, and guard against dangerous organisms. E. coli 0157:H7, on the other hand, can release a powerful toxin – called a “verotoxin” or a “Shiga toxin” – that attacks the lining of the intestine. Some people who are infected with E. coli 0157:H7 do not become ill. Others suffer mild diarrhea. In most cases, severe abdominal cramps are followed by watery, then bloody, diarrhea that subsides within a week or so. Sometimes the diarrhea is accompanied by vomiting and a low‑grade fever.

In about 4 percent of reported E. coli 0157:H7 cases, the Shiga toxins enter the bloodstream, causing hemolytic uremic syndrome (HUS), which can lead to kidney failure, anemia, internal bleeding, and the destruction of vital organs. The Shiga toxins can cause seizures, neurological damage, and strokes. About 5 percent of the children who develop HUS are killed by it. Those who survive are often left with permanent disabilities, such as blindness or brain damage.

Children under the age of five, the elderly, and people with impaired immune systems are the most likely to suffer from illnesses caused by E. coli 0157:H7. The pathogen is now the leading cause of kidney failure among children in the United States. Nancy Donley, the president of Safe Tables Our Priority (STOP), an organization devoted to food safety, says it is hard to convey the suffering that E. coli 0157:H7 causes children. Her six‑year‑old son, Alex, was infected with the bug in July of 1993 after eating a tainted hamburger. His illness began with abdominal cramps that seemed as severe as labor pains. It progressed to diarrhea that filled a hospital toilet with blood. Doctors frantically tried to save Alex’s life, drilling holes in his skull to relieve pressure, inserting tubes in his chest to keep him breathing, as the Shiga toxins destroyed internal organs. “I would have done anything to save my son’s life,” Donley says. “I would have run in front of a bus to save Alex.” Instead, she stood and watched helplessly as he called out for her, terrified and in pain. He became ill on a Tuesday night, the night after his mother’s birthday, and was dead by Sunday afternoon. Toward the end, Alex suffered hallucinations and dementia, no longer recognizing his mother or father. Portions of his brain had been liquefied. “The sheer brutality of his death was horrifying,” Donley says.

As Lee Harding learned, adults in perfect health can be stricken by the pathogen, too. Six months after seemingly recovering from his bout of E. coli 0157:H7 food poisoning, Harding began to urinate blood. He was diagnosed as having a kidney infection, one that he believes was facilitated by residual tissue damage from the Shiga toxins. Although the infection soon passed, Harding still experiences occasional pain three years after eating a Hudson Beef hamburger. Nevertheless, he considers himself lucky.

Antibiotics have proven ineffective in treating illnesses caused by E. coli 0157:H7. Indeed the use of antibiotics may make such illnesses worse by killing off the pathogen and prompting a sudden release of its Shiga toxins. At the moment, little can be done for people with life‑threatening E. coli 0157:H7 infections, aside from giving them fluids, blood transfusions, and dialysis.

Efforts to eradicate E. coli 0157:H7 have been complicated by the fact that it is an extraordinarily hearty microbe that is easy to transmit. E. coli 0157:H7 is resistant to acid, salt, and chlorine. It can live in fresh water or seawater. It can live on kitchen countertops for days and in moist environments for weeks. It can withstand freezing. It can survive heat up to 160 degrees Fahrenheit. To be infected by most food‑borne pathogens, such as Salmonella , you have to consume a fairly large dose – at least a million organisms. An infection with E. coli 0157:H7 can be caused by as few as five organisms. A tiny uncooked particle of hamburger meat can contain enough of the pathogen to kill you.

The heartiness and minute infectious dose of E. coli 0157:H7 allow the pathogen to be spread in many ways. People have been infected by drinking contaminated water, by swimming in a contaminated lake, by playing at a contaminated water park, by crawling on a contaminated carpet. The most common cause of foodborne outbreaks has been the consumption of undercooked ground beef. But E. coli 0157:H7 outbreaks have also been caused by contaminated bean sprouts, salad greens, cantaloupe, salami, raw milk, and unpasteurized apple cider. All of those foods most likely had come in contact with cattle manure, though the pathogen may also be spread by the feces of deer, dogs, horses, and flies.

Person‑to‑person transmission has been responsible for a significant proportion of E. coli 0157:H7 illnesses. Roughly 10 percent of the people sickened during the Jack in the Box outbreak did not eat a contaminated burger, but were infected by someone who did. E. coli 0157:H7 is shed in the stool, and people infected with the bug, even those showing no outward sign of illness, can easily spread it through poor hygiene. Person‑to‑person transmission is most likely to occur among family members, at day care centers, and at senior citizen homes. On average, an infected person remains contagious for about two weeks, though in some cases E. coli 0157:H7 has been found in stool samples two to four months after an initial illness.

Some herds of American cattle may have been infected with E. coli 0157:H7 decades ago. But the recent changes in how cattle are raised, slaughtered, and processed have created an ideal means for the pathogen to spread. The problem begins in today’s vast feedlots. A government health official, who prefers not to be named, compared the sanitary conditions in a modern feedlot to those in a crowded European city during the Middle Ages, when people dumped their chamber pots out the window, raw sewage ran in the streets, and epidemics raged. The cattle now packed into feedlots get little exercise and live amid pools of manure. “You shouldn’t eat dirty food and dirty water,” the official told me. “But we still think we can give animals dirty food and dirty water.” Feedlots have become an extremely efficient mechanism for “recirculating the manure,” which is unfortunate, since E. coli 0157:H7 can replicate in cattle troughs and survive in manure for up to ninety days.

Far from their natural habitat, the cattle in feedlots become more prone to all sorts of illnesses. And what they are being fed often contributes to the spread of disease. The rise in grain prices has encouraged the feeding of less expensive materials to cattle, especially substances with a high protein content that accelerate growth. About 75 percent of the cattle in the United States were routinely fed livestock wastes – the rendered remains of dead sheep and dead cattle – until August of 1997. They were also fed millions of dead cats and dead dogs every year, purchased from animal shelters. The FDA banned such practices after evidence from Great Britain suggested that they were responsible for a widespread outbreak of bovine spongiform encephalopathy (BSE), also known as “mad cow disease.” Nevertheless, current FDA regulations allow dead pigs and dead horses to be rendered into cattle feed, along with dead poultry. The regulations not only allow cattle to be fed dead poultry, they allow poultry to be fed dead cattle. Americans who spent more than six months in the United Kingdom during the 1980s are now forbidden to donate blood, in order to prevent the spread of BSE’s human variant, Creutzfeldt‑Jakob disease. But cattle blood is still put into the feed given to American cattle. Steven P. Bjerklie, a former editor of the trade journal Meat & Poultry , is appalled by what goes into cattle feed these days. “Goddamn it, these cattle are ruminants,” Bjerklie says. “They’re designed to eat grass and, maybe, grain. I mean, they have four stomachs for a reason – to eat products that have a high cellulose content. They are not designed to eat other animals.”

The waste products from poultry plants, including the sawdust and old newspapers used as litter, are also being fed to cattle. A study published a few years ago in Preventive Medicine notes that in Arkansas alone, about 3 million pounds of chicken manure were fed to cattle in 1994. According to Dr. Neal D. Bernard, who heads the Physicians Committee for Responsible Medicine, chicken manure may contain dangerous bacteria such as Salmonella and Campylobacter , parasites such as tapeworms and Giardia lamblia , antibiotic residues, arsenic, and heavy metals.

The pathogens from infected cattle are spread not only in feedlots, but also at slaughterhouses and hamburger grinders. The slaughterhouse tasks most likely to contaminate meat are the removal of an animal’s hide and the removal of its digestive system. The hides are now pulled off by machine; if a hide has been inadequately cleaned, chunks of dirt and manure may fall from it onto the meat. Stomachs and intestines are still pulled out of cattle by hand; if the job is not performed carefully, the contents of the digestive system may spill everywhere. The increased speed of today’s production lines makes the task much more difficult. A single worker at a “gut table” may eviscerate sixty cattle an hour. Performing the job properly takes a fair amount of skill. A former IBP “gutter” told me that it took him six months to learn how to pull out the stomach and tie off the intestines without spillage. At best, he could gut two hundred consecutive cattle without spilling anything. Inexperienced gutters spill manure far more often. At the IBP slaughterhouse in Lexington, Nebraska, the hourly spillage rate at the gut table has run as high as 20 percent, with stomach contents splattering one out of five carcasses.

The consequences of a single error are quickly multiplied as hundreds of carcasses quickly move down the line. Knives are supposed to be cleaned and disinfected every few minutes, something that workers in a hurry tend to forget. A contaminated knife spreads germs to everything it touches. The overworked, often illiterate workers in the nation’s slaughterhouses do not always understand the importance of good hygiene. They sometimes forget that this meat will eventually be eaten. They drop meat on the floor and then place it right back on the conveyer belt. They cook bite‑sized pieces of meat in their sterilizers, as snacks, thereby rendering the sterilizers ineffective. They are directly exposed to a wide variety of pathogens in the meat, become infected, and inadvertently spread disease.

A recent USDA study found that during the winter about 1 percent of the cattle at feedlots carry E. coli 0157:H7 in their gut. The proportion rises to as much as 50 percent during the summer. Even if you assume that only 1 percent are infected, that means three or four cattle bearing the microbe are eviscerated at a large slaughterhouse every hour. The odds of widespread contamination are raised exponentially when the meat is processed into ground beef. A generation ago, local butchers and wholesalers made hamburger meat out of leftover scraps. Ground beef was distributed locally, and was often made from cattle slaughtered locally. Today large slaughterhouses and grinders dominate the nationwide production of ground beef. A modern processing plant can produce 800,000 pounds of hamburger a day, meat that will be shipped throughout the United States. A single animal infected with E. coli 0157:H7 can contaminate 32,000 pounds of that ground beef.

To make matters worse, the animals used to make about one‑quarter of the nation’s ground beef – worn‑out dairy cattle – are the animals most likely to be diseased and riddled with antibiotic residues. The stresses of industrial milk production make them even more unhealthy than cattle in a large feedlot. Dairy cattle can live as long as forty years, but are often slaughtered at the age of four, when their milk output starts to decline. McDonald’s relies heavily on dairy cattle for its hamburger supplies, since the animals are relatively inexpensive, yield low‑fat meat, and enable the chain to boast that all its beef is raised in the United States. The days when hamburger meat was ground in the back of a butcher shop, out of scraps from one or two sides of beef, are long gone. Like the multiple sex partners that helped spread the AIDS epidemic, the huge admixture of animals in most American ground beef plants has played a crucial role in spreading E. coli 0157:H7. A single fast food hamburger now contains meat from dozens or even hundreds of different cattle.