Food, Sex and Salmonella. David Waltner-Toews

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      In one sense, the presence of these organisms in water systems in rural areas was not surprising. Our research group at Guelph had identified rural areas and areas with denser cattle populations that spread manure on farmland as having higher rates of E. coli-related infections than urban areas. We’d already had one tragic outbreak in Ontario related to a well-run farm, in 1986. It was a typical Ontario farm, with sixty-seven cows and calves, some chickens, and some pigs, all well cared for and clean, and seemed the perfect place to take your class of preschoolers. In April of that year, sixty-two preschool children and twelve supervising adults visited this farm. They played in the barn, petted the calves, pulled at the cows’ teats, and gathered a few eggs. For a break, they drank milk (right from the farmer’s tank!) and ate egg cookies (sliced hard-boiled eggs cleverly renamed to induce children to eat them). A good time was had by all.

      Within the next two weeks, forty-two children and four adults came down with abdominal cramps and diarrhea. Three of the children ended up in hospital with hemolytic uremic syndrome. One of the children fell into a coma. All eventually recovered.

      The public health investigators looked everywhere on the farm. Although they found only two calves carrying the organism, they decided that exposure to the unpasteurized milk was the most plausible explanation for what they saw. And yet the farm family, which drank that milk every day, was apparently healthy and not shedding V TEC. Since that time, VTEC had been found to live comfortably and usually without any harmful side effects in the intestines of many cattle, just about wherever cattle are raised, at least in industralized countries.

      Campylobacter, particularly C. jejuni, the other organism found in the water at Walkerton, has been found in many of the same waterborne outbreaks as E. coli. Campylobacter is the bug of choice for cooks, college students, drinkers of raw milk, and, if the aforementioned study in the United Kingdom is to be believed, bottled-water drinkers.

      Although reports of so-called intestinal flu involving curvaceous wiggling organisms in milk go back to 1946, the first major review of Campylobacter jejuni as a possible common cause of diarrhea in people only appeared in the scientific literature in 1977. Just about everywhere researchers have looked for it, they have found it; it is at home in most warm-blooded animals but seems to have a fondness for birds. Today most researchers consider it the most common cause of bacterial diarrhea in the United Kingdom and in North America.

      Campylobacter does not grow very well in food, which is why it causes disease in those who handle raw food, such as cooks. College students, especially those who eat chicken and live with cats, were shown in one study to be a high-risk group. This is related to the “second weaning” phenomenon; those poor suckers are just learning how to cook and they discover that what looked easy when Mom and Dad did it actually requires some skill. Symptoms of the disease—diarrhea, abdominal pain, headache, fever, bloody stools, nausea, and sometimes vomiting— start up to a week after the offending meal and last a week. The reason some of these infections take so long to develop is that the bacteria make their way down to the large intestine before setting up shop, multiplying like mad, and making trouble. That’s also why you see actual blood in the stools of infected people; if the infection is higher up, in the small intestine, the blood is digested and you see black tarry stuff coming out.

      Like Salmonella, Campylobacter doesn’t just cause immediate damage to the gut. Some victims get reactive arthritis I described in the section about salmonellosis. About one in a thousand of those infected with Campylobacter go on to develop a paralytic disease called Guillain-Barré syndrome.

      Campylobacter grows best at about 108°F, which is quite warm. That is why it is often associated with birds, which have a higher internal temperature than us mammals. In one study in the United Kingdom, milk bottles that had been attacked by free-enterprising starlings at the doorstep were found to be a source of infection for people. The birds followed the milk delivery truck and then poked through the tops of the bottles for a fresh drink. Although Campylobacter grows best in birds, it has been isolated from river and sea water, mud, sewage, and sludge.

      This disease appears to be most serious in Western peoples living under conditions of good hygiene. In many developing countries, it seems to be found almost as often in healthy people as in sick people. Clinically normal animals in all countries can carry the organism. In people in developing countries, and in farm animals in North America, the organism can be found with just about equal frequency in healthy and diarrheic individuals.

      Although infection is common, disease, in adults at least, does not appear to be as common as would be expected, suggesting that immunity might be developed by continuous exposure. One study has shown that college students who visited a friend’s home farm got sick from drinking the milk, while the farm family remained cheerfully healthy. One of the costs, then, of protecting children from disease is that, as adults, they are more vulnerable. The alternative, however—to expose kids while young and let the strongest survive—is hardly tenable morally.

      Overall, the presence of V TEC in cows and Campylobacter in a variety of animals didn’t explain the Walkerton outbreak. I visited the farm from which, allegedly, the offending organisms entered the city’s water system. It was run by a veterinarian just outside the town limits. It was no factory farm. Like the farm in the center of the 1986 tragedy, it was an idyllic place, with some corn and a few cows, the kind of place held up as a perfect example of all those who want a return to the simple life of small family farms. The farmer had in place a good Environmental Farm Plan, a program devised by Ontario farmers to assess how well they are managing the landscapes of which they are stewards.

      There are a lot of bad things a person could say about feedlots and factory farms, and I would be one of the first to voice them, but the Walkerton outbreak cannot be laid at that door. The outbreak represented a failure to think systemically; it was a triumph of boundaries, blinders, governmental departmental silos, and small-mindedness. The farm was just outside city limits, so the ecologically important boundaries did not match the political decision-making boundaries. The contaminated well was located on low ground, apparently in a place that engineers had advised against but that made short-term economic sense. The provincial government was ideologically driven and reckless, typical of both communist and free enterprise governments the world over. It cut back on environmental programs, privatized laboratory testing, and downloaded responsibilities without paying attention to whether local officials were up to those responsibilities. The guy who was supposed to monitor water quality didn’t know anything about water quality, drank on the job, and fabricated data. Nobody seemed to be quite sure who was supposed to report to whom or who was ultimately responsible. Because of all the government cutbacks, no one was watching. The government seemed more concerned about building highways, encouraging the trucking industry, and dismissing the values of higher education than they were about public health.