Medical Information The Unwelcome Dinner Guest:
Preventing Foodborne Illness

It must be something I ate," is often the explanation people give for a bout of home-grown "Montezuma's Revenge" (acute diarrhea) or some other unwelcome gastrointestinal upset.

Despite the fact that America's food supply is the safest in the world, the unappetizing truth is that what we eat can very well be the vehicle for foodborne illnesses that can cause a variety of unpleasant symptoms and may be life-threatening to the less healthy among us. Seventy-six million cases of foodborne illness occur in the United States every year.

The Food and Drug Administration has given high priority to combating microbial contamination of the food supply. But the agency can't do the job alone.

Consumers have a part to play, especially when it comes to following safe food-handling practices in the home.

The prime causes of foodborne illness are bacteria, viruses and parasites. Bacteria causing foodborne illness include Escherichia coli O157:H7, Campylobacter jejuni, Salmonella, Staphylococcus aureus, Listeria monocytogenes, Clostridium botulinum, Clostridium perfringens, Vibrio parahaemolyticus, Vibrio vulnificus, and Shigella. Viruses, such as hepatitis A virus and noroviruses, can also cause foodborne illness. Parasites are another origin of this type of illness and include Giardia lamblia, Cyclospora cayetanensis, and Cryptosporidium parvum.

These organisms can become unwelcome guests at the dinner table. They can be in a wide range of foods, including meat, milk and other dairy products, spices, chocolate, seafood, and even water.

Specific foods that have been implicated in foodborne illnesses are unpasteurized fruit and vegetable juices and ciders; raw or undercooked eggs or foods containing undercooked eggs; chicken, tuna, potato and macaroni salads; cream-filled pastries; and fresh produce.

Bacteria such as Listeria monocytogenes, Vibrio vulnificus, Vibrio parahaemolyticus, and Salmonella have been found in raw seafood. Oysters, clams, mussels, scallops, and cockles may be contaminated with hepatitis A virus.

Careless food handling sets the stage for the growth of disease-causing "bugs." For example, hot or cold foods left standing too long at room temperature provide an ideal climate for bacteria to grow. Improper cooking also plays a role in foodborne illness.

Foods may be cross-contaminated when cutting boards and kitchen tools that have been used to prepare a contaminated food, such as raw chicken, are not cleaned before being used for another food, such as vegetables that will not be cooked.


Common symptoms of foodborne illness include diarrhea, abdominal cramping, fever, headache, vomiting, severe exhaustion, and sometimes blood or pus in the stools. However, symptoms will vary according to the type of organism and the amount of contaminants eaten.

In rare instances, symptoms may come on as early as a half hour after eating the contaminated food, but they typically do not develop for several days or weeks. Symptoms of viral or parasitic illnesses may not appear for several weeks after exposure. Symptoms usually last only a day or two, but in some cases can persist a week to 10 days. For most healthy people, foodborne illnesses are neither long-lasting nor life-threatening. However, they can be severe in the very young, the very old, and people with certain diseases and conditions.

These conditions include:

When symptoms are severe, the victim should see a doctor or get emergency help. This is especially important for those who are most vulnerable. For mild cases of foodborne illness, the individual should drink plenty of liquids to replace fluids lost through vomiting and diarrhea.

Prevention Tips

The idea that the food on the dinner table can make someone sick may be disturbing, but there are many steps you can take to protect your families and dinner guests. It's just a matter of following basic rules of food safety.

Prevention of foodborne illness starts with your trip to the supermarket.

Safe Storage

Keep It Clean

The first cardinal rule of safe food preparation in the home is: Keep everything clean.
The cleanliness rule applies to the areas where food is prepared and, most importantly, to the cook.

Keep Temperature Right

The second cardinal rule of safe home food preparation is: Keep hot foods hot and cold foods cold.

If you don't have a food thermometer, look for other signs of doneness. For example:

Protect food from cross-contamination after cooking, and eat it promptly.

And here are just a few more parting tips to keep your favorite dishes safe.

Though all these dos and don'ts may seem overwhelming, remember, if you want to stay healthy, when it comes to food safety, the old saying "rules are made to be broken" does not apply!

Keep Your Food Safe

Always be sure to practice these four simple steps to food safety:

CLEAN: Wash hands and surfaces often
Wash your hands, cutting boards, dishes, utensils, and counter tops with hot, soapy water before, during, and after preparing food.

SEPARATE: Don't cross-contaminate
Always keep raw meat, poultry, seafood and their juices away from other foods.

COOK: Cook to proper temperatures
Use a food thermometer to make sure foods are cooked to a safe internal temperature.

CHILL: Refrigerate promptly
Be sure to refrigerate foods within two hours. Set your refrigerator no higher than 40 F and the freezer at 0 F.

How Long Will It Keep?

Following is a rundown of storage guidelines for some of the foods that are regulars on America's dinner tables.



In Refrigerator
40 degrees Fahrenheit
(5 degrees Celsius)

In Freezer
0 F (-18 C)

Fresh Meat:
Beef: Ground
Steaks and roasts

1-2 days
3-5 days

3-4 months
6-12 months

Pork: Chops

3-5 days
1-2 days
3-5 days

4-6 months
3-4 months
4-6 months

Cured meats:
Lunch meat

3-5 days
1-2 days

1-2 months
1-2 months


1-2 days

2-3 months

lean (such as cod, flounder, haddock)
fatty (such as blue, perch, salmon)

1-2 days
1-2 days

up to 6 months
2-3 months

Chicken: whole

1-2 days
1-2 days
1-2 days

12 months
9 months
3-4 months

Dairy Products:
Swiss, brick, processed cheese
Ice cream, ice milk

3-4 weeks
5 days

1 month
2-4 months

Eggs: fresh in shell

3 weeks
1 week


* Cheese can be frozen, but freezing will affect the texture and taste.
(Sources: Food Marketing Institute for fish and dairy products, USDA for all other foods.)

This information has been obtained from FDA and is updated by Life Alert ® frequently.