Food Safety: How to Prevent Foodborne Illness

When a patient’s immune system is weak, the body has fewer defenses against bacteria, parasites, or viruses that can be found in food.

Germs in food and drinks can sometimes cause an illness or infection of the gastrointestinal (GI) tract. This type of sickness is called a foodborne illness or food poisoning.

Symptoms of foodborne illness

Common symptoms of foodborne illness are like stomach virus symptoms. They include:

• Diarrhea
• Stomach pain or cramps
• Nausea and vomiting
• Fever
• Chills
• Headache
• Muscle aches and weakness

Most people start feeling sick within the first couple days after infection. But foodborne illness symptoms can develop within a few hours. Or they can take up to a week to appear. 

If you think your child may have a foodborne illness:

• Notify your care team. 
• Make sure your child drinks plenty of fluids.
• Keep the suspected food and packaging materials, if possible. The care team may want to examine it.  
• Contact the local health department if the suspected food was eaten at a restaurant or other public place. This may help prevent other people from getting sick.

Ways to prevent foodborne illness

Basic steps can help prevent illnesses from food. These are especially important if your child’s immune system is weak. Your care team can share more food safety steps to take.

Prevent illness from foods by doing the following:

• Shop smart.
• Handle food properly.
• Avoid cross-contamination from foods and surfaces.
• Cook food thoroughly.
• Be careful when dining out.
• Avoid foods with a high risk of causing foodborne illness.

Shop smart

Practice food safety at the grocery store.

• Check “sell-by” and “use-by” dates. Avoid expired products.
• Look for the word “pasteurized” on the labels of milk, cheese, and juice.
• Choose only fresh products. Look for:
  • Packaging dates on fresh meats, poultry, and seafood
  • Marks on fruits and vegetables
  • Sealed packaging on boxed foods

Avoid the following foods:

• Damaged, swollen, rusted, or dented cans
• Deli foods
• Unrefrigerated cream and custard-containing desserts and pastries
• Foods in self-serve or bulk containers
• Soft-serve yogurt and ice cream
• Free food samples
• Cracked or unrefrigerated eggs
• Frozen foods with signs of thawing or refreezing
• Food on the FDA recall list.

Other shopping tips:

• Pick up frozen and refrigerated foods just before checking out, especially in hot weather.
• Refrigerate groceries immediately after returning from the store.
• Place packages of raw meat in separate plastic bags before placing it next to other food.

Handle and store food properly

Taking care to handle food properly reduces the chance of foodborne illness. Foodborne illness often starts when foods are not washed or stored correctly.

• Wash hands with warm, soapy water.
  • Wash hands both before and after preparing food.
  • Always wash hands before eating.
• Maintain proper temperature.
  • Keep hot foods warmer than 140°F (60°C) and cold foods cooler than 40°F (4.4°C).
  • Do not leave foods at room temperature longer than 1 hour.
  • Thaw meat, fish, or poultry in the microwave or refrigerator. Use a dish to catch drips.
  • Never thaw food on the kitchen counter. Germs grow rapidly at room temperature.
  • Use defrosted foods right away. Do not refreeze them.
  • Put foods that can spoil in the refrigerator within 2 hours of buying or preparing.
• Wash fruits and vegetables well before peeling or cutting.
  • Rinse the leaves of leafy vegetables individually under running water.
  • Wash any dirt with a clean scrubber.
  • Wash packaged salads and other prepared produce marked as pre-washed.
  • Avoid blackberries, raspberries, and other fruits and vegetables that are hard to wash.
• Avoid vegetables that:
  • Appear slimy or moldy
  • Have already been cut at the grocery store
• Other suggestions:
  • Wash tops of canned foods with soap and water before opening.
  • Avoid raw vegetable sprouts.
  • Never taste food with any utensil that will be used to stir or serve food.
  • Throw away eggs with cracked shells.
  • Do not eat foods that look or smell strange.
  • Throw away food that has mold on it. Cutting off the mold will not remove the germs.

For a more detailed guideline to safely storing food in the refrigerator and freezer, visit the Cold Food Storage Chart.

Avoid cross-contamination

Bacteria from uncooked foods can easily transfer to other foods and surfaces.

Simple ways to improve kitchen safety include:

• Keep utensils, counters and cutting boards clean.
  • Use a clean knife to cut different foods.
  • Wash counters and cutting boards with hot, soapy water. Or use a cleaning solution made of 1 part bleach and 10 parts water.
  • Use disinfecting wipes that are safe to use around food.
• Keep foods separate.
  • Store raw meat in a sealed container away from other ready-to-eat food in the refrigerator.
  • Set foods apart on countertops.
  • Use different cutting boards for raw meats, fruit, and vegetables.
• Use a clean plate for cooked meat when grilling.

Cook food thoroughly

Cook food to safe temperatures, especially meat and poultry. This reduces the chance of food-related illness.

• Use a meat thermometer inserted into the middle of the thickest part of the food.
  • Cook meats to 165°F (74°C).
  • Cook poultry to 180°F (83°F).
• Cook meat until it is no longer pink.
• Make sure meat juices are clear.
• When cooking in the microwave, prevent cold spots where bacteria can survive.
  • Rotate the dish during cooking.
  • Heat leftovers with a lid or vented plastic wrap.
  • Stir often.

Eat out safely

Eating out can present added challenges because less is known about how food is stored and prepared.

Here are some ways you can reduce your risk in restaurants:

• Check the health inspection rating for the restaurant. This is a good way to see how well the restaurant meets food safety rules and requirements.
• Talk to the server. Explain any specific needs ahead of time.
  • Ask that food be prepared fresh.
  • Request single-serving packages of condiments.
  • Drink fruit juices only if pasteurized, which reduces bacteria.
  • Ask for meats to be cooked well-done.
• Stay away from certain menu options.
  • Avoid self-serve or shared food such as salad bars and buffets.
  • Limit raw fruits and vegetables.
  • Do not drink freshly squeezed juice.
  • Avoid food with raw or undercooked eggs.
• Other dining tips:
  • Make sure utensils are set on a napkin, clean tablecloth, or placemat, instead of on the table. If they aren’t, ask for new ones.
  • Ask for a container for leftovers. Put the food in yourself.
  • Refrigerate leftovers as soon as possible. Avoid leftover rice and pasta.

Avoid high-risk foods

The following foods can be unsafe for patients with a weak immune system. Always follow your care team’s instructions.

Do not allow your child to eat or drink:

• Raw or undercooked eggs or any product containing raw or undercooked eggs. Cook eggs until the yolk and white are firm.
• Raw dairy products including raw or unpasteurized milk or cheese and fresh soft cheeses), such as:
  • Brie
  • Camembert
  • Blue cheese (Roquefort, gorgonzola, stilton, etc.)
  • Feta
  • Mexican-style queso fresco
• Raw or undercooked shellfish
  • Sushi
  • Clams
  • Oysters
  • Mussels
  • Scallops
  • Steamed seafood such as mussels and snails
• Well water. Tap water is usually allowed as well as bottled water that reads “reverse osmosis.”
• Raw, rare, or undercooked meat or poultry. All meat should be cooked well-done.
• Ready to eat foods that can be unsafe
  • Uncooked hot dogs
  • Fresh-sliced meats from deli counter (all lunch meat must be heated to 165°F)
  • Other deli-style foods
  • Honey and unpasteurized maple syrup
  • Sprouts (such as bean sprouts and alfalfa sprouts)
  • Raw, unroasted nuts
  • Dried fruits
• Tea bags. Some pasteurized bottled tea is allowed.
• Black Pepper. Only use black pepper packets that have been sterilized.
• Avoid these foods in cafeterias
  • Sushi bar
  • Roast beef from deli bar
  • Lettuce and vegetables on the salad bar that have started to brown

Those being treated on the transplant unit should avoid ice machines and fountain drink machines.

More information

To learn more about food safety for people with cancer and other illnesses, visit the FDA's Food Safety page.

Learn more about how to Clean, Separate, Cook, and Chill for Food Safety.

Related Content