Safe Food_ Bacteria, Biotechnology, and Bioterrorism - Marion Nestle [32]
Single-source outbreaks, however, also illustrate the vulnerability of a centralized food supply. In the most dramatic instance, a Salmonella outbreak in 1994 affected more than 220,000 people in 41 states. Its source was a surprise: packaged ice cream. The ice cream was produced from a premixed liquid base delivered to the processing plant in a tanker truck that previously had carried unpasteurized liquid eggs.24 Such incidents are fully preventable, as these chapters explain.
Abusing Antibiotics
The use of antibiotics in animal agriculture affects foodborne illness in ways that are especially troubling. Growers treat infected animals with antibiotics, of course, but they sometimes give antibiotics to whole herds or flocks as a preventive measure. Despite the questionable effects of this practice, what most alarms safety experts is the routine use of low-dose antibiotic drugs as growth promoters, a practice that began in the 1950s and seems impossible to stop. Antibiotics are chemicals that prevent bacteria from reproducing (see chapter 6), but for reasons poorly understood, animals grow faster and need less feed when low-dose antibiotics are added to their food or drinking water. This treatment kills some bacteria, but not all; those naturally resistant to the antibiotics survive and multiply. The unintended consequence of this practice is the proliferation of antibiotic-resistant bacteria. If antibiotic-resistant bacteria infect people and cause disease, the disease will be untreatable.
This possibility is not merely theoretical. By the mid-1970s, researchers already knew that such uses increased the population of antibiotic-resistant bacteria in farm animals as well as in their human caretakers. In 1977, alarmed by such findings, the FDA proposed to restrict the use of antibiotics in animal feed. Congress, however, overruled this idea under pressure from farm-state lawmakers, livestock producers, and the makers of the drugs. These groups all argued that such restrictions were unwarranted because they were not sufficiently supported by science.25 This early blockage of safety regulations established a seemingly unshakable precedent.
In the following years, researchers reported that pathogenic bacteria resistant to multiple antibiotics could be passed from animals to humans. Every time the FDA attempted to restrict the use of the drugs, Congress again intervened, mainly as a result of drug industry lobbying and the invocation of “science” as an obstructive measure. Instead of taking action, Congress ordered the FDA to conduct further studies. By the early 1980s, the FDA stopped fighting this issue and instead proposed more relaxed standards, leading one Congressman to observe that the driving force behind the FDA’s retreat on this issue was “protection of the health of the animal drug industry.”26
In the mid-1990s, scientists demonstrated that Campylobacter resistant to high-potency antibiotics could be transferred from chickens to humans. The dangers of antibiotic-resistant foodborne bacteria were becoming more evident as more species acquired resistance to more and more antibiotics. Although calls for corrective action increased in urgency, a committee of the National Research Council (NRC) argued in 1999, “the use of drugs in the food-animal production industry is not without some problems and concerns, but it does not appear to constitute an immediate public health concern.”27 At least one critic viewed this surprisingly sanguine conclusion as just what one might expect when members of a scientific panel are “overwhelmingly associated with or linked to the drug industry.”28
During this