Free Safe Food: The Politics of Food Safety by Marion Nestle Page B

everywhere: around us, on us, and in us. They inhabit soil and water, skin and digestive tract, and any place that provides favorable conditions for growth (and hardly any place does not). They are incredibly small, and incredibly numerous. All kinds—viruses, bacteria, protozoa, and yeasts—are ubiquitous in raw foods. Most are harmless. Some are even “friendly,” helping to make bread, wine, vinegar, soy sauce, yogurt, and cheese, and keeping our digestive tracts healthy. Others are less helpful; left to their own devices, they rot apples, mold bread, and spoil meat. Some are decidedly unfriendly, and cause more than 200 known foodborne diseases.
    To avoid getting food poisoning, we take precautions: we preserve foods and we cook them. Preservation methods—some ancient, some modern (among them salt, sugar, alcohol, acid, and freeze-drying)—all inhibit microbial growth. Refrigeration slows down growth, and freezing does so even more. Cooking, a brilliant invention, not only makes foods taste better but also kills microbial pathogens. Cooked foods, however, do not remain sterile. Microbes in air, water, and other foods can recontaminate them, as can microbes on packages, plates, utensils, cutting boards, and hands. With common measures such as hand washing, dish washing, and other such basic precautions, we live with most food microbes in relative peace. Our digestive and immune systems take care of those that survive cooking. Mostly, we do not worry much about them.
    TABLE 3 . The most frequent microbial causes of foodborne disease in the United States: estimated numbers of illnesses, hospitalizations, and deaths, 1999

    SOURCE : Mead PS, Slutsker L, Dietz V, et al.
Emerging Infectious Diseases
1999;5:607–625.
    NOTE : Illnesses generally include some form of gastrointestinal distress—diarrhea, vomiting, cramps—as well as the problems indicated. These figures continue to constitute the basis of prevalence estimates.
    Whether we
should
worry more about them is a matter of how we perceive risk. For most of us as individuals, an occasional episode of stomach upset—if not too severe—is tolerable. From a public health standpoint, however, the cost to society of such episodes is staggeringly high. Table 3 lists, for example, the most frequent causes of foodborne disease, along with estimates of their cost in illness, hospitalization, and death. Viruses cause most foodborne illnesses, but some bacteria and protozoa are also to blame. Nearly all induce highly unpleasant symptoms, usually mild but sometimes very severe. Table 3 , however, lists only the best-known pathogens. The causes of the vast majority of episodes of foodborne illness remain obscure. 6 Furthermore, pathogenic microbes pervade the food supply. A
Consumer Reports
investigation in 1998, for example, identified
Campylobacter
in 63% of market chickens,
Salmonella
in 16%, and both in 8%. Pathogenic
Salmonella
can pass from chickens to their eggs. Because egg production is so enormous, a low rate of infection—one out of every 10,000 eggs, for example—means 4.5 million infected eggs each year. 7
Counting Cases and Estimating Costs
    If harmful microbes are widespread in food and if they make so many people sick, why isn’t everyone—the food industry, health officials, and the public—doing something to prevent them from getting into food? One reason is that most episodes of food poisoning are not very serious. Another is that it is difficult to collect accurate information about the number of cases and their severity. Attributing a bout of diarrhea to food rather than to other causes is no simple matter. Most of us eat several foods at a time, several times a day, in several different places. How could we possibly know which food might be responsible for our getting sick, especially if there is a delay in the onset of symptoms? I cannot imagine bothering to call a doctor about a brief stomach upset. Even if I did, the doctor might not suspect food