This is the No. 1 reason people get sick on Thanksgiving

It's holiday season in the U.S., which means lots of time with family friends and food. And this combination also means lots of illness will go around, from RSV, flu and COVID-19 to foodborne diseases.

Also known as food poisoning, foodborne illnesses occur when you eat something contaminated with disease-causing germs, including bacteria, parasites or viruses, and are left with an unpleasant bout of gastrointestinal symptoms, according to the U.S. Centers for Disease Control and Prevention.

Every year in the U.S., an estimated one in six people (or 48 million) get sick, 128,000 become hospitalized, and 3,000 die from foodborne diseases, per the CDC.

“We know that outbreaks of foodborne illness can and do happen around Thanksgiving,” Laura Ford, Ph.D., epidemiologist in the division of foodborne, waterborne and environmental diseases at the CDC, tells TODAY.com. “The CDC does not collect data specifically related to holidays, but some foods people enjoy during Thanksgiving can lead to serious foodborne illnesses, if the foods aren’t properly handled, cooked, stored or reheated.”

Common foodborne illnesses from turkey

Turkey, which is often the centerpiece of a Thanksgiving meal, can be contaminated with salmonella, campylobacter, clostridium perfringens and other germs, says Ford. Most of these can be killed by cooking foods to a safe internal temperature, Ford says, but raw poultry and its juices can also cross-contaminate anything they touch. Raw eggs used in stuffings, casseroles and desserts can also be contaminated with germs like escherichia coli, Ford adds.

During Thanksgiving, people are typically cooking much larger quantities of food than usual often under pressure, which allows for more mistakes, according to Robert Gravani, Ph.D., professor emeritus of food science at Cornell University.

“Those larger quantities of food require more attention to detail around the preparation, cooking, and cleanup,” Gravani tells TODAY.com. This applies to both beginners and experienced cooks because food safety mishaps are easier to make than you'd think.

“Contamination can happen at each step of food production chain, from farm to fork,” says Ford. These germs can even come from your own hands, such as norovirus. Also known as the "stomach flu," norovirus is the leading cause of foodborne illness outbreaks in the U.S., according to the CDC, and peaks during the winter months.

“Once the contamination occurs, further mishandling, like undercooking the food or leaving it at unsafe temperatures, can make foodborne illness more likely,” Ford says.

Salmonella

Salmonella is one of the most prevalent foodborne illnesses, and it’s typically associated with raw poultry and eggs, says Gravani. Between 2017 and 2019, there was an outbreak of a type of multi-drug resistant salmonella that's common in live turkeys; it caused a reported 356 cases in 42 states, according to the National Institutes of Health. While not all raw poultry is infected with salmonella, it’s safest to assume it does and take precautions, Gravani says.

C. perfringens

According to the CDC, clostridium perfringens bacteria are one of the most common causes of food poisoning in the U.S., leading to nearly 1 million illnesses every year. Outbreaks occur most often in November and December.

Clostridium perfringens can be found on raw meat and poultry, in the intestines of animals and humans, and in the environment, says Ford. The bacteria produces spores, which act like a protective coating that helps the bacteria survive high cooking temperatures, per the CDC. These can grow and multiply rapidly in cooked food left in the “danger zone" (between 40 degrees and 140 degrees Fahrenheit) for longer than two hours, says Ford.

Leaving large batches of food sitting out at room temperature is a fairly common practice on Thanksgiving, the experts note, because many people wait to store and refrigerate food until after everyone is finished with their meal or done circling back for seconds.

Common sources of clostridium perfringens infections include turkey, beef, gravies and soups, Ford says, but it can also come from other foods (including vegetarian dishes) cooked in large batches and held at unsafe temperatures. This is why outbreaks tend to occur in settings where food is served to big groups of people, such as catered events or cafeteria settings, Ford says.

Past examples include a 2015 outbreak that sickened 40 at least people and a 2005 outbreak that involved hundreds of cases, both linked to catered Thanksgiving lunches at work, according to Ford.

Signs of foodborne illness

It can take anywhere from several hours to a few days after consuming contaminated food to develop symptoms, says Ford. For clostridium perfringens, symptoms typically begin within six to 24 hours after eating contaminated food, but for salmonella, symptoms can start anywhere from six hours to six days after, says Ford.

“The most common symptoms of foodborne illness are an upset stomach, stomach cramps, nausea, vomiting, diarrhea and fever,” says Ford. Most people will have a mild illness lasting a few hours to several days, but some people can develop severe illness requiring hospitalization.

Complications of foodborne illness include dehydration, hemolytic uremic syndrome (when the small blood vessels in the kidneys are damaged), and long-term health issues, like Guillain Barre syndrome, says Ford. In rare cases, severe food poisoning is deadly.

Anyone can get a foodborne illness, but some groups of people are more likely to become infected and have severe illness, Ford says. These include children under the age of 5, adults over 65, people with weakened immune systems and pregnant women.

How to prevent foodborne illness

It’s important that cooks follow these four steps to minimize the risk of foodborne illness and ensure their Thanksgiving dinner is safe and healthy, Gravani says:

  • Clean your hands before, during and after cooking, and sanitize utensils, cutting boards and countertops often.

  • Separate raw meat, poultry and seafood and eggs from other foods while storing in the refrigerator, preparing dishes, and cooking, says Ford. This includes cooking stuffing outside the bird in its own dish. Frozen, raw turkey should be kept in its own dish or bag while defrosting, which can be done in the refrigerator, cold water, or the microwave, per USDA guidelines. Store raw meat in containers so the juices don't drip near other foods.

  • Cook all food to a safe internal temperature using a meat thermometer inserted into the thickest part of the food, Gravani says. Poultry and casseroles should be cooked to 165 degrees Fahrenheit, eggs to 160 degrees, and beef and seafood to 145 degrees, according to the U.S. Department of Agriculture. "We can't look at the color or the texture to determine doneness."

  • Chill all leftovers as soon as possible after serving to minimize the time the food is left out in the danger zone. Cooked food should be refrigerated within two hours, and larger pieces of food should be cut up or divided so they can be stored in smaller containers, Ford says.

Refrigerated leftovers will only last three or four days, says Ford. Freezing will help your leftovers keep longer, she notes, but always make sure to reheat food to 165 degrees Fahrenheit to prevent illness. Finally, if you are feeling sick, especially with any kind of gastrointestinal illness, avoid cooking if you can.

This article was originally published on TODAY.com