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:
- liver disease, either from excessive
alcohol use, viral hepatitis, or
- hemochromatosis, an iron disorder
- stomach problems, including
previous stomach surgery and low
stomach acid (for example, from
- immune disorders, including
- long-term steroid use, as for
asthma and arthritis.
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.
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.
- Pick up your packaged and canned
- Don't buy food in cans that are
bulging or dented or in jars that
are cracked or have loose or bulging
- Don't eat raw shellfish and
use only pasteurized milk and cheese
and pasteurized or otherwise treated
ciders and juices if you have a
health problem, especially one
that may have impaired your immune
- Choose eggs that are refrigerated
in the store. Before putting them
in your cart, open the carton and
make sure that the eggs are clean
and none are cracked.
- Select frozen foods and perishables
such as meat, poultry or fish last.
Always put these products in separate
plastic bags so that drippings
don't contaminate other foods in
your shopping cart.
- Don't buy frozen seafood if the
packages are open, torn or crushed
on the edges. Avoid packages that
are above the frost line in the
store's freezer. If the package
cover is transparent, look for
signs of frost or ice crystals.
This could mean that the fish has
either been stored for a long time
or thawed and refrozen.
- Check for cleanliness at the
meat or fish counter and the salad
bar. For instance, cooked shrimp
lying on the same bed of ice as
raw fish could become contaminated.
- When shopping for shellfish,
buy from markets that get their
supplies from state-approved sources;
stay clear of vendors who sell
shellfish from roadside stands
or the back of a truck. And if
you're planning to harvest your
own shellfish, heed posted warnings
about the safety of the water.
- Take an ice chest along to keep
frozen and perishable foods cold
if it will take more than an hour
to get your groceries home.
- The first rule of food storage
in the home is to refrigerate or
freeze perishables right away.
The refrigerator temperature should
be 40 degrees Fahrenheit (5 degrees
Celsius), and the freezer should
be zero F (minus 18 C). Check both
"fridge" and freezer periodically
with a refrigerator/freezer thermometer.
- Poultry and meat heading for
the refrigerator may be stored
as purchased in the plastic wrap
for a day or two. If only part
of the meat or poultry is going
to be used right away, it can be
wrapped loosely for refrigerator
storage. Just make sure juices
can't escape to contaminate other
- Wrap tightly foods destined for
the freezer. Leftovers should be
stored in tight containers.
- Store eggs in their carton in
the refrigerator itself rather
than on the door, where the temperature
- Seafood should always be kept
in the refrigerator or freezer
until preparation time.
- Don't crowd the refrigerator
or freezer so tightly that air
can't circulate. Check the leftovers
in covered dishes and storage bags
daily for spoilage. Anything that
looks or smells suspicious should
be thrown out.
- A sure sign of spoilage is the
presence of mold, which can grow
even under refrigeration. While
not a major health threat, mold
can make food unappetizing. Most
moldy foods should be thrown out.
But you might be able to save molding
hard cheeses, salami, and firm
fruits and vegetables if you cut
out not only the mold but a large
area around it. Cutting the larger
area around the mold is important
because much of the mold growth
is below the surface of the food.
- Always check the labels on cans
or jars to determine how the contents
should be stored. Many items besides
fresh meats, vegetables, and dairy
products need to be kept cold.
For instance, mayonnaise and ketchup
should go in the refrigerator after
opening. If you've neglected to
refrigerate items, it's usually
best to throw them out.
- Some precautions will help make
sure that foods that can be stored
at room temperature remain safe.
Potatoes and onions should not
be stored under the sink because
leakage from the pipes can damage
the food. Potatoes don't belong
in the refrigerator, either. Store
them in a cool, dry place. Don't
store foods near household cleaning
products and chemicals.
- Check canned goods to see whether
any are sticky on the outside.
This may indicate a leak. Newly
purchased cans that appear to be
leaking should be returned to the
store, which should notify the
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.
- Wash hands with warm water and
soap for at least 20 seconds before
starting to prepare a meal and
after handling raw meat or poultry.
- Cover long hair with a net or
scarf, and be sure that any open
sores or cuts on the hands are
completely covered. If the sore
or cut is infected, stay out of
- Keep the work area clean and
uncluttered. Wash countertops with
a solution of 1 teaspoon of chlorine
bleach to 1 quart of water or with
a commercial kitchen cleaning agent
diluted according to product directions.
They're the most effective at getting
rid of bacteria.
- Also, be sure to keep dishcloths
clean because, when wet, they can
harbor bacteria and may promote
their growth. Wash dishcloths weekly
in hot water in the washing machine.
- Sanitize the kitchen sink drain
periodically by pouring down the
sink a solution of 1 teaspoon of
bleach to 1 quart of water or a
commercial kitchen cleaning agent.
Food particles get trapped in the
drain and disposal and, along with
the moistness, create an ideal
environment for bacterial growth.
- Use smooth cutting boards made
of hard maple or a non-porous material
such as plastic and free of cracks
and crevices. Avoid boards made
of soft, porous materials. Wash
cutting boards with hot water and
soap, using a scrub brush. Then,
sanitize them by washing in an
automatic dishwasher or by rinsing
with a solution of 1 teaspoon of
chlorine bleach to 1 quart of water.
- Always wash and sanitize cutting
boards after using them for raw
foods, such as seafood or chicken,
and before using them for ready-to-eat
foods. Consider using one cutting
board only for foods that will
be cooked, such as raw fish, and
another only for ready-to-eat foods,
such as bread, fresh fruit, and
- Always use clean utensils and
wash them between cutting different
- Wash the lids of canned foods
before opening to keep dirt from
getting into the food. Also, clean
the blade of the can opener after
each use. Food processors and meat
grinders should be taken apart
and cleaned as soon as possible
after they are used.
- Do not put cooked meat on an
unwashed plate or platter that
has held raw meat.
- Wash fresh fruits and vegetables
thoroughly, rinsing under running
water. Don't use soap or other
detergents. If necessary--and appropriate--use
a small scrub brush to remove surface
Keep Temperature Right
The second cardinal rule of safe home food preparation is: Keep hot foods hot and cold foods cold.
- Use a digital or dial food thermometer to ensure that meats are completely
cooked. Insert the thermometer into the center of the food and wait 30 seconds
for accurate measurement. Beef, lamb, and veal should be cooked to at least
145 F (63 C); pork and ground beef to 160 F (71 C); whole poultry and thighs
to 180 F (82 C); poultry breasts to 170 F (77 C); and ground chicken or turkey
to 165 F (74 C).
- Eggs should be cooked until the white and the yolk are firm. Avoid foods
containing raw eggs, such as homemade ice cream, mayonnaise, eggnog, cookie
dough and cake batter, because they carry a Salmonella risk. Their
commercial counterparts usually don't because they're made with pasteurized
eggs. Cooking the egg-containing product to an internal temperature of at
least 160 F (71 C) will kill the bacteria.
- Seafood should be thoroughly
cooked to an internal temperature
of at least 145 F (63 C). Fish
that's ground or flaked, such as
a fish cake, should be cooked to
at least 155 F (68 C), and stuffed
fish to at least 165 F (74 C).
If you don't have a food thermometer, look for other signs of doneness. For example:
- Fish is done when the thickest
part becomes opaque and the fish
flakes easily when poked with a
- Shrimp can be simmered three
to five minutes or until the shells
- Clams and mussels are steamed
over boiling water until the shells
open (five to 10 minutes). Then
boil three to five minutes longer.
- Oysters should be sautéed,
baked or boiled until plump, about
Protect food from cross-contamination
after cooking, and eat it promptly.
- Cooked foods should not be left
standing on the table or kitchen
counter for more than two hours.
Disease-causing bacteria grow in
temperatures between 40 and 140
F (4 and 60 C). Cooked foods that
have been in this temperature range
for more than two hours should
not be eaten.
- If a dish is to be served hot,
get it from the stove to the table
as quickly as possible. Reheated
foods should be brought to a temperature
of at least 165 F (74 C). Keep
cold foods in the refrigerator
or on a bed of ice until serving.
This rule is particularly important
to remember in the summer months.
- After the meal, leftovers should
be refrigerated as soon as possible.
(Never mind that scintillating
dinner table conversation!) Meats
should be cut in slices of three
inches or less and all foods should
be stored in shallow containers
to hasten cooling. Be sure to remove
all the stuffing from roast turkey
or chicken and store it separately.
Giblets should also be stored separately.
Leftovers should be used within
And here are just a few more parting tips to keep your favorite dishes safe.
- Don't thaw meat and other frozen
foods at room temperature. Instead,
move them from the freezer to the
refrigerator for a day or two;
or defrost submerged in cold water.
You can also defrost in the microwave
oven or during the cooking process.
Cook foods immediately after defrosting
in the microwave or cold water.
- Never taste any food that looks
or smells "off" or comes out of
leaking, bulging or severely damaged
cans or jars with leaky lids.
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
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
COOK: Cook to proper temperatures
Use a food thermometer to make sure
foods are cooked to a safe internal
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.
40 degrees Fahrenheit
(5 degrees Celsius)
0 F (-18 C)
Steaks and roasts
lean (such as cod, flounder,
fatty (such as blue, perch, salmon)
up to 6 months
Swiss, brick, processed cheese
Ice cream, ice milk
fresh in shell
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