How to share a meal without sharing germs? A doctor explains

As people gather for Thanksgiving, they might be bringing along some unexpected guests.

These get-togethers are occurring as respiratory viruses such as influenza are on the rise, and Covid-19 and the respiratory syncytial virus are circulating as well. Additionally, there are also foodborne illnesses going around that can result in stomach upset and other symptoms.

How can people protect themselves as they’re preparing for holiday gatherings? What should hosts keep in mind as they are planning events and serving food? And what symptoms are signs a person should seek medical care?

To help us with these questions, I spoke with CNN wellness medical expert Dr. Leana Wen. Wen is an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She previously was Baltimore’s health commissioner, with responsibilities that included overseeing infectious diseases as well as food safety.

CNN: What types of illnesses can be transmitted during Thanksgiving and other holiday get-togethers?

Dr. Leana Wen: I’d think about the illnesses in two categories. The first is respiratory illnesses, like the flu, RSV and the common cold. Someone who is infected coughs or sneezes, then those droplets containing viruses land on your nose or mouth. Or they touch their nose, then touch a surface, and then you touch that surface and then your nose or mouth. Some viruses, like the virus that causes Covid-19, are also airborne, and can be transmitted by someone who is coughing, singing or just speaking and breathing near you.

The second category is foodborne infections. These are also quite common. According to the US Centers for Disease Control and Prevention, there are around 9 million episodes of foodborne illnesses each year. The most common pathogen implicated in these infections is norovirus. This can be spread through food and drink and can also be spread from person. If you touch an object that an infected person touched, and then touch your mouth, you could get norovirus. You could also contract it by eating from the same utensils or drinking from the same cup as an infected person.

A subcategory under foodborne infections are infections that result from ingesting the food itself — for example, if it’s undercooked or spoiled. Such pathogens include salmonella and E. coli.

CNN: How should people decide what level of precautions to take?

Wen: Most people don’t want to get sick, of course, but some people need to take extra precautions because they are vulnerable to severe illness. Older people, babies and very young children, pregnant individuals, and those who are immunocompromised or have other serious underlying medical conditions all fall into this category. They should take additional precautions based on how much they wish to avoid infection.

For instance, they may wish to avoid very large gatherings in indoor crowded spaces and instead opt for get-togethers with a small group of family and friends who have taken steps to limit their own virus risks in the preceding week. They may choose to spend most of their time together in well-ventilated spaces. While traveling to the event, and in other public spaces, they could wear well-fitting N95s or equivalent masks. And, of course, they should be sure that they have their recommended vaccines and access to antiviral treatment if they were to become ill.

CNN: What should hosts keep in mind as they are planning events?

Wen: Hosts should check in with their guests to see whether any of them are in this category of individuals who are very vulnerable and wishing to take extra precautions. If so, they could have a discussion of what additional steps should be taken to reduce risk.

For instance, could doors and windows be open during meals? Could there be instructions encouraging people not to attend if they have symptoms? Could hosts suggest that everyone take a rapid Covid-19 test prior to arrival? Could hosts place sanitizer throughout the event and encourage frequent use? Any of these steps could help reduce the risk of respiratory and gastrointestinal illness.

CNN: Are buffet tables a good idea?

Wen: Buffet tables could add a bit more risk for three reasons, but there are ways to reduce the risk with some planning.

First, people often congregate near a buffet. A lot of people in a tight space adds to the risk of person-to-person spread. Hosts could ask a few people to get food one at a time and then sit down instead of congregating. They can also open windows and doors.

Second, buffets generally have a lot of items that are touched by numerous people, like serving spoon, pitchers and lids. Knowing that this is the case, hosts can place hand sanitizer at the end of the buffet line and at dining spaces to encourage people to use it after helping themselves at the buffet and before eating.

Third, buffets often involve food that’s lying out for a long time. Depending on the type of food, it could be out for too long and then become a breeding ground for various pathogens. Hosts should be attentive to the amount of time perishable food is out — generally, perishable items should not be left out for more than two hours. Remember the old maxim: Hot food should be kept hot, and cold food should be kept cold.

CNN: Is it better to forgo buffets in favor of plated meals?

Wen: If the steps above can be followed, buffets may be no riskier than plated meals. However, if many people are likely to congregate near a buffet table, for instance, hosts can plate meals for their more vulnerable guests and have them dine in a less crowded area with open windows and good air circulation.

CNN: What other food safety tips can help to reduce the spread of illnesses?

Wen: Don’t undercook meat. There are excellent resources online that outline what internal temperatures different kinds of meat and poultry should be cooked to.

Be conscious of what containers and utensils have touched raw meat. Don’t put vegetables that you intend to serve as salad items or cooked meat into these containers. And be sure to wash vegetables and fruit before serving.

People who are preparing food should take extra care to wash their hands very well. If they touched raw meat, they need to wash their hands with hot water and soap before handling other food. Everyone should practice good hygiene with frequent handwashing.

CNN: Finally, what symptoms should people watch out for — how do they know when they need to seek medical care?

Wen: Symptoms of respiratory illnesses include fever, cough, sneezing and body aches. Symptoms of gastrointestinal illnesses include nausea, vomiting, diarrhea and abdominal pain. Those with foodborne infections can also develop body aches and flu-like symptoms, too.

People should seek medical care if they have shortness of breath, severe abdominal pain, or are vomiting so much they cannot keep down fluids. This is especially true for people vulnerable to severe illness. And those who have symptoms should stay away from others to reduce their chance of further spreading infections.

For more CNN news and newsletters create an account at CNN.com