Food Poisoning 101: What to Know and How to Stay Safe
With food safety seemingly making news headlines more today, it's impossible not to worry about food poisoning, whether it's caused by E. Coli, Listeria, or Salmonella. Recent food recalls from a major cereal company and even a popular grocery store show us that any business—even ones you trust—is vulnerable to a foodborne illness. And while an outbreak can damage a company’s reputation, it shouldn't necessarily prevent you as a consumer from buying future products. The best defense is educating yourself about different infections, what their symptoms are, how long they last, and also what steps you can take to protect yourself whether at home or dining out.
What is Food Poisoning?
A foodborne illness results from eating contaminated food or drinking unsafe water. The Center for Disease Control (CDC) estimates roughly 48 million cases of food poisoning each year, which translates to one in six people. While this sounds like a high number, it’s largely due to stronger monitoring programs in effect today. Even so, the World Health Organization (WHO) is significantly concerned about foodborne illness-related deaths across the world. WHO believes the key to better food safety is better education and government regulation in both low-income and high-income countries.
Each foodborne illness has a different incubation period, or time it takes after infection to experience symptoms, ranging from hours to days. Most people experience nausea, vomiting, stomach pain, and diarrhea. While food poisoning typically subsides on its own after several days, extreme cases require hospitalization. Foodborne illnesses can often be tough to track, as two people can have different reactions to the same pathogen. Determinants include how much of the contaminated food was consumed and the person’s overall health. Regardless, you are most at-risk if you are pregnant, elderly, an infant, or if you have a suppressed immune system.
How Does Food Poisoning Happen?
In order for bacteria to thrive, they must have the right conditions—a sufficient food source, optimal temperature, and moisture. If allowed to thrive, a single bacteria can multiply quickly in a short amount of time. Here’s a closer look at the conditions bacteria need:
- Temperature: Known as the “danger zone,” the ideal temperature range for bacteria growth is between 40°F and 140°F. This is why it’s important to set your refrigerator at 40°F or colder, and why it’s important to cook chicken to an internal temperature of 165°F. Under 40°F, bacteria growth drastically slows, while above 160°F, bacteria are completely wiped out. While freezing foods stops bacteria growth, it does not kill them entirely.
- Food: Many foods, in particular raw chicken, pork, and eggs, provide the perfect environment for bacteria to grow. While raw milk is growing in popularity, it can be a concern because it has not been pasteurized, a process that heats liquids to high temperatures to kill bacteria. The CDC strongly discourages drinking raw milk due to the risk of foodborne illness, while the FDA has banned its sale entirely across state borders.
- Moisture: Like humans—and all living creatures for that matter—bacteria need water to survive. A wet, damp space is their perfect environment.
What are the Most Common Foodborne Illnesses?
The CDC reports over 250 type of foodborne illnesses in existence, most of which stem from bacteria, viruses, or parasites. The nine listed below are the ones you typically hear about the most.
Salmonella: One of the most common foodborne illnesses in the U.S., Salmonella bacteria can lurk in raw or undercooked meats, poultry, fish, eggs, raw milk, cheese, and juice. Symptoms, which usually appear 6 to 48 hours after infection, include diarrhea, fever, vomiting, and abdominal pain. One of the best preventative steps is to cooking raw foods to their USDA-recommended internal temperatures.
E. Coli: It sounds scary, but E. Coli are naturally-occurring, completely harmless bacteria that dwell in our intestines. However, one particular strain—E. Coli O157:H7—is deadly and can cause life-threatening symptoms. Raw or undercooked ground beef, unpasteurized milk or cider are known carriers of this strain, which can lead to complications including hemorrhagic colitis, an acute gastrointestinal disease. It typically takes 1 to 3 days for symptoms to appear, and the infection can linger for over a week. To protect yourself, cook and reheat meat properly and prevent cross-contamination, or the mixing of bacteria from different foods, by sanitizing food prep areas.
Shigella: Shigella is mainly spread through infected feces, and causes severe diarrhea. You can contract the disease is by eating food that’s handled by someone infected with the bacteria. It can take 4 to 7 days for symptoms to start, but the infection should pass in 24 to 48 hours. Practicing frequent hand washing, especially if you work in a kitchen, is crucial to protecting yourself from the illness.
Clostridium Perfringens: Often called the “cafeteria” or “buffet” germ,” this bacteria is associated with large portions of pasta bakes, casseroles, stews, and soups that sit in the danger zone for extended amounts of time. Symptoms appear quickly—about 8 to 16 hours after infection—but you should start to recover after a day. To protect yourself and others, replace buffet foods often and by divide large cooked food into smaller portions before refrigerating. The less time cooked food spends in the danger zone, the less of a chance for bacteria to thrive.
Listeria: This bacteria can thrive and grow at extreme temperatures below 40 degrees, but it can be killed through pasteurization. Listeria is less common than other pathogens, and occurs in raw milk, soft cheeses, raw and undercooked meats, ready-made foods such as hot dogs, deli meats, and even frozen waffles. While you may experience typical gastrointestinal symptoms 9 to 48 hours after infection, complications can surface up to 6 weeks later. Listeria is especially dangerous for pregnant women and can lead to miscarriage and premature or still birth.
Campylobacter: This bacteria is more common during hot summer months and can result from raw or undercooked poultry and meat, raw milk, and contaminated water. Its most identifiable quality is severe diarrhea. The onset time is 2 to 5 days after infection, and the duration of the illness is about a week. You can prevent Campylobacter by avoiding cross-contamination between raw and cooked foods, and by washing fruits and vegetables beforehand.
Norovirus: Often called the “Winter vomiting bug” or mistakened for stomach flu, Norovirus is one of the most common foodborne illnesses. This virus can come from eating raw produce, improperly cooked or reheated foods, and shellfish from a contaminated water source. Norovirus is extremely contagious and can easily be spread through food, drink, or anything touched by an infected person. Symptoms arise in 12 to 48 hours and last no longer than 2 to 3 days.
Hepatitis A: Unlike most food pathogens that attack the gastrointestinal system, the virus Hepatitis A attacks the liver. It’s found in contaminated water or raw fruits and vegetables, shellfish, and undercooked food. Symptoms typically appear in between 15 and 50 days. Once you have Hepatitis A, your body builds an immunity to prevent you from ever catching it again. The highest risk of Hepatitis A is in rural, developing countries, but it’s possible to contract the illness anywhere. The CDC strongly recommends vaccination if you plan to spend an extended amount of time in countries where Hepatitis A is more common.
Cryptosporidium: Often shortened to “Crypto,” this parasite is most common in developing countries without safe drinking water, but you can also find it in chlorinated swimming pools (it’s chlorine-resistant). You’re likely to experience diarrhea, stomach cramps, and a low-grade fever between 2 and 10 days after initial infection. Nitazoxanide, an anti-parasitic drug, is a known effective treatment for Crypto.
What is the Best Way to Treat Food Poisoning?
For most healthy adults, rest and adequate fluid intake can kick a bout of food poisoning. If you do experience vomiting and diarrhea, prevent dehydration by sipping an electrolyte rich drink such as Gatorade. Most doctors will discourage antidiarrheal drugs, since your body is actively trying to rid itself of the bacteria. When you’re feeling better, stick to bland foods or the BRAT diet—bananas, rice, applesauce, and toast—until fully recovered.
While many foodborne illnesses pass through your body without the need for treatment, others are much more severe. Symptoms such as bloody diarrhea, or a combination of high fever, stiff neck, and severe headache may evidence more dangerous pathogens such as Listeria or E. Coli O157:H7. If this is the case, seek a doctor’s care immediately.
How Can I Prevent Food Poisoning?
While there are certain circumstances beyond your control, such as a country’s drinking water or mishandled food at a restaurant, thankfully there is plenty that you can do to protect yourself—and others. The key to staying healthy is educating yourself. Stay on top of outbreaks and food recalls by subscribing to the FDA’s free email subscription service and download their FoodKeeper App to learn the safe storage time for any food or beverage. In the meantime, here are 5 steps you can take in your kitchen to minimize your chances of picking up a foodborne illness.
1. Wash your Hands: Whether you’re cooking or dining out, wash your hands before and after any interactions you have with food. Work soap through your hands for at least 20 seconds, then rinse and dry them thoroughly.
2. Avoid Cross-Contamination: If you’re using the same cutting board to prep raw meat and vegetables, you’re at high risk for cross-contamination. Prevent the mixing of potentially harmful bacteria by using separate cutting boards for raw meat and by thoroughly cleaning boards after each use.
3. Wash Produce Beforehand: Never soak, always rinse produce to ensure any bacteria on the surface are properly routed down the drain. Rinse delicate produce such as berries in a strainer, tumble greens in a salad spinner, and use a produce brush to scrub dirt from hard-skinned fruits and veggies such as melons or potatoes. After doing so, wipe the produce dry with a paper towel to decrease moisture. Lastly, remove any bruises or dark spots on the produce, as these areas could harbor bacteria or mold.
4. Replace Sponges and Dishtowels Frequently: We can bet that most people, ourselves included, use the same sponge for far too long. A sponge’s inherent moistness coupled with its location (i.e. your sink) makes it the perfect breeding ground for bacteria. Dishtowels carry a similar risk—toss them in the washing machine with your other towels and linens as often as you can. Do not use a dish towel to clean up juice from raw meat such as ground beef or chicken, as this is an easy way to spread potential pathogens. Instead, use a paper towel or antibacterial wipe.
5. Cook Proteins Thoroughly: The USDA has established safe minimum internal temperatures for all proteins. Here’s their general rule of thumb: 145°F for whole meat, 160°F for ground meat, 165°F for all poultry, and 165°F for leftovers and casseroles. While duck is technically poultry, its meat is treated more like beef or lamb and is typically cooked to 145°F for medium rare. While many chefs can tell a meat’s doneness simply by touch, we recommend using a food thermometer at home.
6. Transport Food Properly: The USDA recommends leaving cooked food at room temperature for no more than two hours. When packing your kid’s lunch or bringing yours to the office, include an ice pack to help keep food cold until it can be refrigerated. When you’re finished eating, dispose of any uneaten perishable food, instead of keeping it in the container for the rest of the day. Lastly, run your lunch bag through the laundry or wash out your lunch box with soapy water frequently to prevent bacteria growth.
For more information about foodborne illnesses, current recalls, and how to protect yourself, visit foodsafety.gov.
Source: Duyff MS, RDN, FAND, CFCS, Roberta L. Academy of Nutrition and Dietetics Complete Food & Nutrition Guide, Revised & Updated 5th Edition. New York: Mifflin Harcourt Publishing Company, 2017. Print.