FOOD SAFETY FOR THE CONSUMER
With a focus on Shiga-toxin producing E. coli
By Margaret Loehnig
“Fever, nausea, vomiting, and diarrhea.” With the onset of such symptoms, many people brace themselves for a long night spent sitting on a cold bathroom floor, hugging a porcelain toilet and ridding themselves of the contents of last night’s dinner. When calling in sick to work the next morning, they may report that they have been struck with a case of the stomach flu. However, the USDA points out that another common category of illness, often overlooked, presents itself with the same nasty symptoms: foodborne illness (USDA, 2006). The statistics are striking; millions of people in the United States are sickened each year from food poisoning, 325,000 are hospitalized, and 5,000 die (MODHSS, 2010). The good news is that foodborne illness is preventable in the grand majority of cases.
One common way that people develop foodborne illness is by ingesting Escherichia Coli (E. coli for short), which is a type of bacteria. Some kinds of E. coli make people sick by producing a toxin called a “Shiga toxin;” this class of bacteria are called Shiga toxin-producing E. coli, or STEC. Because the strand E. coli 0157:H7 is the most commonly identified strand in North America, it will be the focus of this discussion (CDC, 2008). However, it is important to note that many other kinds of STEC are also capable of causing disease.
According to the Centers for Disease Control and Prevention (CDC), the most likely victims of STEC illnesses are very young children, elderly persons, and persons with weakened or compromised immune systems, but in reality, anyone can become infected. Symptoms typically appear 3-4 days after the person has ingested the harmful bacteria, but an incubation period of anywhere between 1 and 10 days is considered normal (CDC, 2008). Symptoms vary but typically include severe stomach cramps, often-bloody diarrhea, vomiting, and low-grade fever.
Illnesses usually last for 5-7 days, but they can also be life-threatening. For example, the CDC estimates that 5-10% of those who have STEC infections develop a complication called hemolytic uremic syndrome (HUS), which can be deadly because it can cause a person’s kidneys to stop working. Symptoms of this condition include decreased frequency of urination, feeling very tired, and losing pink color in the cheeks and lower eyelids. Persons suspected of suffering from this condition need to be hospitalized in order to combat the illness (CDC, 2008). Other possible complications of foodborne illnesses include arthritis and meningitis (CDC, 2008).
STEC are constantly present in the natural environment. These bacteria live in the guts of animals such as cattle, goats, sheep, deer, and elk, but they typically do not make these hosts sick. The problem begins when STEC is transferred to humans. Typically, this occurs when humans swallow tiny (sometimes invisible) amounts of human or animal feces containing STEC. Traces of feces may be swallowed when working with cows or changing diapers, of course, but STEC is also transferred to others in less obvious ways. These include, but are not limited to, swallowing contaminated lake water while swimming, eating food prepared by a person who did not wash his or her hands properly, consuming the bacteria after touching animals in petting zoos, and consuming infected water, milk, meat, or produce (CDC, 2008).
However, as mentioned earlier, the grand majority of cases of foodborne illness, including those induced by STEC, are preventable. The Department of Health and Senior Services (DHSS) and other sources offer a multitude of suggestions regarding how to keep food safe and prevent foodborne illness. These suggestions can be divided into the clear categories of “before the cooking process,” “during the cooking process,” and “after the cooking process” tips.
FOOD SAFETY TIPS
BEFORE COOKING
One of the simplest measures that any person can take to prevent the spread of foodborne illness is to properly wash his or her hands before preparing or eating any meal. Many people who believe they are adequately washing their hands are sorely mistaken. According to a study conducted by the American Society of Microbiology, 97% of females and 92% of males said they washed their hands, but those numbers turned out to be 75% of females and 58% of males upon observation (MNDOH, 2006). A proper hand-washing technique suggested by the DHSS includes using soap and warm water; washing vigorously for 10-20 seconds, making sure to reach all surfaces of the hands including the wrists, between the fingers, and under the finger nails; rinsing well; drying hands with a paper towel; and using a paper towel to turn off the water (MODHSS, 2010). It is certainly important to wash your hands before preparing a meal and eating, but you should also wash your hands after using the restroom, coughing/sneezing, touching cuts or skin infections, handling raw meat, and touching pets or other animals. According to the DHSS, “nearly half the cases of foodborne illnesses could be prevented by better hand-washing by food handlers” (MODHSS, 2010). In addition, hand sanitizer is a helpful follow-up to hand-washing, but it should never be used to replace this valuable technique.
Some foods should simply never be ingested in the first place because they have such a high risk of containing harmful bacteria that can make people ill. These foods include raw milk, unpasteurized dairy products, unpasteurized juices (such as fresh apple cider), raw meat, and raw cookie dough (CDC, 2008).
Many homeowners are all too familiar with the common scenario of opening up the fridge and wondering if a certain food has gone bad. In cases of suspected food spoilage, food should never simply be tasted, smelled, or eye-balled in order to determine its safety. It is true that in some cases, the presence of mold or other growths may indicate that a food has reached its expiration date and should not be consumed. However, some foods may look and smell fine, but if they have been stored at room temperature for over 2 hours, microscopic bacteria may have been allowed to grow. The safe temperature for foods in refrigerators is between 35 and 45 degrees Fahrenheit, and freezers should be kept at 0 degrees Fahrenheit or below (MODHSS, 2010). For more information on how to determine the safety of food in the case of power outages or other instances in which food has been kept at a non ideal temperature for an extended period of time, please visit http://www.foodsafety.gov/.
DURING COOKING
When I was a child, my mother often asked me to take certain meats out of the freezer while she was at work and let them thaw on the counter all day. This practice is actually not considered safe, because it allows any germs present on the food to thrive. Safer alternatives to this practice include thawing the food under running water (70 degrees Fahrenheit or below) for less than 2 hours, placing the food in the refrigerator to thaw, or thawing the food in the microwave as part of the cooking process (MODHSS, 2010).
It is also important to make sure that raw meats are cooked to the appropriate internal temperature before they are consumed. Safe internal temperatures for various meats include 165 degrees Fahrenheit for poultry, 155 for ground meat, and 145 for fish and pork (MODHSS, 2010). It is not sufficient to judge the doneness of meat by its internal color. According to a study performed by the USDA, “25% of hamburgers with a brown internal color were not cooked to the proper temperature” (MODHSS, 2010). Instead of simply eyeballing the meat, it is essential to use a meat thermometer to judge the safety of consuming the food.
The cooking process is often the time that foodborne pathogens are allowed to enter the food we eat because of the prevalence of cross contamination. Cross contamination occurs when a person handling raw meats, eggs, fish, or other foods containing harmful pathogens touches cooking utensils, cutting boards, or cooking surfaces and spreads the pathogens to ready-to-eat foods in the process. This mode of transmission can be interrupted by washing your hands after handling raw foods, washing utensils and cutting boards that have come in contact with raw foods, and disinfecting counter surfaces frequently (MODHSS, 2010).
AFTER COOKING
A simple guideline to follow is to “keep hot foods hot and cold foods cold.” Hot foods should be kept at 135 degrees Fahrenheit or above, and cold foods should be held below 41 degrees Fahrenheit (MODHSS, 2010). This guideline is compromised when already-prepared foods are allowed to sit out on the counter for extended periods of time. As a result, you should strive to store leftovers promptly.
Leftovers are ideally stored in the refrigerator in shallow containers (2 inches tall or less) so that the cooling process can be accelerated and the buildup of harmful bacteria can be prevented. Storing foods in larger containers may keep foods warm and allow harmful bacteria to grow (MODHSS, 2010).
Occasionally, even after following all of the above feasible tips to increase the safety of your food, foodborne illness will still occur. In these cases, it is important to be prepared to limit the course of the illness and prevent the spread of the illness between the affected person and his or her close contacts.
Unfortunately, if a person develops a foodborne illness, antibiotics are not a useful method of combating the illness. In fact, taking antibiotics may even increase the risk of developing hemolytic uremic syndrome (HUS). It is also important to avoid taking antidiarrheal agents, such as Imodium ®, because your body needs to expel the pathogens in order to eliminate the illness (CDC, 2008). One of the most helpful things you can do is to make sure that the ill person stays hydrated. In addition, frequent hand-washing is a good idea for the person affected as well as any people who will come in contact with him or her, such as family members and friends. STEC bacteria may be shed in a person’s feces for several weeks, even after the person no longer feels ill. In rare cases, bacteria continue to be shed for several months (CDC, 2008).
If you do suspect foodborne illness is the cause of your suffering or the suffering of a loved one, it may be appropriate to report your suspicion in order to prevent others from getting sick. The USDA suggests that you preserve the evidence if at all possible by wrapping a portion of the suspect food securely, making it with the word “Danger,” and freezing it. If the packaging material of the food is available, it may also be helpful to save this as well. It is not a bad idea to record the food type, the date, the time consumed, and when the onset of symptoms occurred. If the food is a USDA-inspected product, you may wish to call the USDA Meat and Poultry Hotline at 1-888-674-6854 or send an e-mail to mphotline.fsis@usda.gov. If you suspect that you developed food poisoning from eating at a restaurant or other large gathering, or if the suspect food is a commercial product, call your local health department. They just may be able to prevent the illness of others like you by notifying the public of a pathogenic outbreak (USDA, 2006). For more information on E. coli, food safety, or what to do when foodborne illness occurs, please contact the Missouri Department of Health and Senior Services:
Alyce Turner
Health Educator in the Bureau of Communicable Disease Control and Prevention
SOURCES
Minnesota Department of Health, (2006). Minnesota handwashing tool kit Retrieved from http://www.health.state.mn.us/handhygiene/stats/statistics.html
Missouri Department of Health and Senior Services, Bureau of Environmental Regulations and Licensure. (2010). Food safety for group functions Retrieved from http://www.dhss.mo.gov/safety/foodsafety/pdf/Food_Safety_for_Group_Functions.pdf
United States Department of Agriculture, Food Safety and Inspection Service. (2006). Foodborne illness: what consumers need to know Retrieved from http://www.fsis.usda.gov/fact_sheets/Foodborne_Illness_What_Consumers_Need_to_Know/index.asp
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