Preventing E. coli Infection
What can we do to prevent E. coli infection?
Since there is no fail-safe food safety program, consumers need to “drive defensively” as they navigate from the market to the table. It is no longer enough to take precautions only with ground beef and hamburgers; anything ingested by family members can be a vehicle for infection.
Shiga toxin-producing E. coli are so widely disseminated that a wide variety of foods can be contaminated. Direct animal-to-person and person-to-person transmission is not uncommon. Following are steps you can take to protect your family.
- Practice meticulous personal hygiene. This is true not only for family members (and guests), but for anyone interfacing with the food supply chain. Remember that E. coli bacteria are very hardy (e.g., can survive on surfaces for weeks) and that only a few are sufficient to induce serious illness. Since there is no practical way of policing the hygiene of food service workers, it is important to check with local departments of health in order to identify any restaurants that have been given citations or warnings. The emerging practice of providing sanitation “report cards” for public display is a step in the right direction.
Be sure to clean and sanitize all imported and domestic fruits or vegetables. All can be carriers of disease. If possible, fruits should be skinned, or at least vigorously scrubbed and/or washed. Vegetables (and of course meat) should be cooked to a core temperature of at least 160 degrees Fahrenheit for at least 15 seconds. If not cooked, fruits and vegetables should be washed to remove any dirt or other material, and then soaked in chlorinated water (1 teaspoon of household bleach in one quart of water, soaked for at least 15 minutes). They can then be rinsed in clean water to remove the chlorine taste. This will remove most, but not all, bacteria. In the case of leafy vegetables, bacteria may not be limited to the leaf’s surface, but can actually reside within the minute circulatory system of the individual vegetable leaves. Be careful to avoid cross contamination when preparing and cooking food, especially if beef is being served. This requires being very mindful of the surfaces (especially cutting boards) and the utensils used during meal preparation that have come in contact with uncooked beef and other meats. This even means that utensils used to transport raw meat to the cooking surfaces should not be the same that are later used to remove the cooked meat (or other foodstuffs) from the cooking surfaces. Do not allow children to share bath water with anyone who has any signs of diarrhea or “stomach flu”. And keep any toddlers still in diapers out of all bodies of water (especially wading and swimming pools). Do not let any family members touch or pet farm animals. Merely cleaning the hands with germ “killing” wipes may not be adequate! Wear disposable gloves when changing the diapers of any child with any type of diarrhea. Remember that E. coli O157:H7 diarrhea initially is non-bloody, but still very infectious. If gloves are not available, then thorough hand washing is a must. Remember that achieving a brown color when cooking hamburgers does not guarantee that E. coli bacteria have been killed. This is especially true for patties that have been frozen. Verifying a core temperature of at least 160 degrees Fahrenheit for at least 15 seconds is trustworthy. Small, disposable meat thermometers are available, a small investment compared to the medical expense (and grief) of one infected family member. Avoid drinking (and even playing in) any non-chlorinated water. There is an added risk if the water (well, irrigation water or creek/river) is close to, or downstream from any livestock.
What is our government doing to protect us from E. coli?
Congress enacts statutes designed to ensure the safety of the food supply. The U.S. food agencies are accountable to the President, to the Congress, which has oversight authority, to the courts, which review regulations and enforcement actions, and to the public. The principal federal agencies responsible for providing consumer protection are:
- U.S. Department of Agriculture’s (USDA) Food Safety and Inspection Service (FSIS) has the responsibility for ensuring that meat, poultry, and egg products are safe, wholesome, and accurately labeled.
Food and Drug Administration (FDA) is charged with protecting consumers against impure, unsafe, and fraudulently labeled food other than in areas regulated by the Food Safety and Inspection Service (FSIS). Centers for Disease Control and Prevention (CDC), is part of the Department of Health and Human Services (DHHS), and has a food safety mission that falls within its surveillance and outbreak response activities, but that is unlike those of USDA and FDA. CDC does not have regulatory authority. Even so, it is the lynch pin of our country’s food safety program. Its pivotal role is exemplified by the following excerpts:
On Nov. 15, 2006, an official from CDC testified before the Senate Committee on Health, Education, Labor and Pensions, regarding CDC’s food safety activities, with a special emphasis on the recent E. coli spinach outbreak.  The official testified, in part, that:
As an agency within the Department of Health and Human Services (HHS), CDC leads federal efforts to gather data on foodborne illnesses, investigate foodborne illnesses and outbreaks, and monitor the effectiveness of prevention and control efforts. CDC is not a food safety regulatory agency but works closely with the food safety regulatory agencies, in particular with HHS’s Food and Drug Administration (FDA) and the Food Safety and Inspection Service (FSIS) within the United States Department of Agriculture (USDA). CDC also plays a key role in identifying prevention strategies and building state and local health department epidemiology, laboratory, and environmental health capacity to support foodborne disease surveillance and outbreak response. Notably, CDC data are used to help document the effectiveness of regulatory interventions.
In partnership with state health departments, CDC collects surveillance information on foodborne illness. The states collect data about cases of infections that are of public health importance from doctors and clinical laboratories. CDC helps states investigate outbreaks that are large, severe, or unusual. . . .
CDC specializes in the critically important public health activities of surveillance, epidemiologic response, and investigation of disease. . . .
In 1993, there was a large multi-state outbreak of
E. coli O157 infections in the Western United States. In order to prevent future severe outbreaks . . . an effective surveillance network called PulseNet was developed. PulseNet is the national network for molecular sub-typing of foodborne bacteria . . . and is coordinated by CDC. The laboratories participating in PulseNet are in state health departments, some local health departments, USDA, and FDA. PulseNet plays a vital role in surveillance for, and investigation of, foodborne illness outbreaks that were previously difficult to detect. For example, when a clinical laboratory makes a diagnosis of E. coli O157, the bacterial strain is sent to a participating PulseNet laboratory where it is sub-typed, or “DNA fingerprinted” [every E. coli has a unique DNA pattern]. The “fingerprint” is then compared with other patterns in the state, and uploaded electronically to the national PulseNet database maintained at CDC, where it can be compared with the patterns in other states. This gives us the capability to rapidly detect a cluster of infections with the same pattern that is occurring in multiple states. The PulseNet database, which includes approximately 120,000 DNA patterns, is available to participating laboratories and allows them to rapidly compare patterns. Once a cluster of cases with the same DNA pattern is identified, epidemiologists then interview patients to determine whether cases of illness are linked to the same food source or other exposures they have in common. The strength of this system is its ability to identify patterns even if the affected persons are geographically far apart, which is important given the reality of U.S. food distribution systems. If patients have been exposed to a specific food or to another source of infection, and the case count for that illness is larger than one would expect for the time period, the cluster is determined to be an outbreak with a common source.
The group of epidemiologists in the states and at CDC who regularly investigate and report on these outbreaks is called OutbreakNet. The Outbreak Net participants use standardized interview methods and forms and rapidly share the investigation data. With this collaboration, outbreaks can be investigated in a matter of days rather than weeks. As a consequence, CDC [that has no regulatory authority] can more rapidly alert FDA and USDA about implicated food products associated with foodborne illness so that all three agencies can collaboratively take actions to protect public health. Tracing the implicated food back from consumption through preparation, to distributors, and sometimes back to a field or farm can help determine how the contamination occurred, stop distribution of the contaminated product, and prevent further outbreaks from occurring. . . .
Another important surveillance network is CDC’s Foodborne Diseases Active Surveillance Network (FoodNet). This network is collaboration among 10 state health departments, the USDA, and FDA . . . FoodNet conducts active surveillance for foodborne diseases and also conducts related epidemiologic studies that look at both sporadic and outbreak foodborne infections to help public health officials better understand the epidemiology of foodborne diseases in the United States and how to target prevention strategies. We have PulseNet to detect possible outbreaks, OutbreakNet to investigate and report them, and FoodNet to track general trends and define where more effective prevention strategies are needed (emphasis added).
These networks stand prepared to detect a public health event related to the food supply. For example, after investigations of PulseNet-identified clusters of
E. coli infection focused attention on the need for specific controls during ground beef processing, regulatory and industry practices changed in 2002, and the incidence of E. coli O157:H7 infections began to decrease sharply. By 2005, the incidence of E. coli O157 infections, as measured in FoodNet, had dropped 29% [Since 2006, however, the incidence appears to be rising, primarily due to outbreaks linked to lettuce and spinach].