In the Kitchen: Prevent the Spread of Infection

Bacteria can spread anywhere in the kitchen. So, it's important to wash your hands and kitchen surfaces before and after preparing food. Bacteria can spread from one surface to another without you knowing it. If the bacteria gets into food, they can cause foodborne illnesses.

Sources of contamination

Most viruses and bacteria that cause colds, flu, and foodborne illnesses are spread by hand-to-hand or hand-to-food contact. People with hepatitis A, Norwalk-like viruses (noroviruses), or the bacteria staphylococcus and streptococcus can pass these illnesses on to others by handling food. Also, a person who is ill from a foodborne illness, such as hepatitis A, can pass that illness on to others by handling food.

Raw meats, poultry, and fish carry a large variety of harmful bacteria. One of the most serious is Escherichia coli 0157:H7, the organism found mostly in undercooked hamburger. It is one of the most common causes of foodborne illness, according to the CDC. This bacterium causes hemolytic uremic syndrome, an often-fatal disease that strikes mostly children. Older adults are also at high risk.

Chicken, turkey, and fowl are associated with shigella, salmonella, and campylobacter, bacteria that cause diarrhea, cramping, and fever. Most meat can be contaminated with toxoplasmosis, a parasitic disease dangerous to both pregnant women and fetuses.

Seafood, particularly oysters, clams, and other shellfish, can be contaminated with the vibrio species of bacteria that causes diarrhea, or with hepatitis A virus.

Unpasteurized cheese and some meat can be contaminated with Listeria monocytogenes, a strain of bacteria that can cause disease in people and miscarriage or damage to the fetus in pregnant women. Listeria is often found in soft cheeses, such as brie, and more frequently in imported cheeses than in domestic cheeses. Listeria is one of the few bacteria that grow well in the 40°F temperature of the refrigerator.

Contaminated vegetables and fruits can carry a variety of organisms and parasites, depending on where they were grown and how they were processed, the CDC says.

Contaminated kitchen gadgets

Items in the kitchen become contaminated by contact with contaminated people, foods, pets or other environmental sources.

The first and foremost suspect "gadget" in the kitchen is the human hand. Too often, people don't wash their hands before preparing food. More frequently, people don't wash their hands between handling potentially contaminated foods such as meat and other less-likely-to-be-contaminated foods such as vegetables. This "cross-contamination" is a leading cause of foodborne disease, the CDC says.

Kitchen-specific items that often become contaminated include:

  • Can openers

  • Cutting boards

  • Countertops; most people use their countertops not only for food preparation, but also for potentially contaminated items, such as grocery bags, mail or household objects

  • Dishrags, towels, sponges, and scrubbers

  • Garbage disposals

  • Sink drains and P-trap; this is the J-shaped pipe under the sink that retains a quantity of water to block sewer gas from seeping back up through the sink

  • Refrigerators

  • Complex appliances, such as food processors, blenders, and eggbeaters

Cleaning vs. disinfecting

Many people believe that if it appears clean, it's safe. A kitchen can look perfectly clean, yet be contaminated with a host of disease-causing organisms. Cleaning and disinfecting are two different processes. Cleaning removes grease, food residues, and dirt, as well as a large number of bacteria, but cleaning may also spread other bacteria around. Disinfecting kills organisms (bacteria, virus and parasites).

Disinfectants and sanitizers are widely available as liquids, sprays, or wipes. Any of these works well, killing almost all the bacteria and viruses. You can also make your own inexpensive disinfectant by adding one tablespoon liquid chlorine bleach to one gallon of water. Store the solution in a spray bottle and make a new solution every 2 to 3 days.

You should clean thoroughly before you disinfect, because a buildup of food or grease will not allow the disinfectant to penetrate.

How you dry your dishes and utensils also plays an important role in kitchen sanitation. From least effective to most effective, drying processes can be ranked:

  • Drying with a dishtowel (least effective)

  • Drying with a paper towel

  • Air drying

  • Drying in the dishwasher

  • Sterilizing cycle in dishwasher (if so equipped)

Cleaning hands and disinfecting the gadgets

You should wash your hands before eating, before preparing food, and after cleaning up the food preparation area, the CDC says. Outside the kitchen, you should wash your hands after using the bathroom, after handling pets or cleaning up after them, after caring for another sick person, or any time that you think your hands might be contaminated. Use soap and water, making sure to clean the palms, the top surfaces, between the fingers, and up the wrists. Short fingernails help maintain cleanliness.

According to the CDC, plain soap works the best. Even though studies have shown that antibacterial soaps and cleaners have not been definitively linked to antibiotic-resistant infections, they do not kill germs remarkably better than regular soap. However, antibacterial hand sanitizers can come in handy when there is no water for washing. The CDC makes the following suggestions for good hand washing technique:

  • Use soap and warm running water.

  • Lather your hands well.

  • Wash all surfaces, including between your fingers, the backs of your hands, wrists, and under your fingernails.

  • Wash thoroughly for 20 seconds. (Ask your children to say their ABCs while they wash—that way they'll spend enough time washing.)

  • Rinse well.

  • Make this a habit, especially before meals and after using the bathroom, whether you're sick or not.

If soap and water are not available, an alcohol-based hand sanitizer that contains at least 60% alcohol can be used to clean your hands. When using these products:

  • Apply the gel to the palm of one hand.

  • Rub your hands together.

  • Rub the product over all surfaces of your hands and fingers until they are dry.

The following are ways to prevent infections from kitchen gadgets:

  • Can openers. Whether hand-held or electric, clean after each use. After cleaning, wipe with your bleach solution (or commercial disinfectant) and allow to air dry.

  • Cutting boards. If practical, keep two cutting boards, one for meat and one for fruits and vegetables. Clean after each use. The meat cutting board should be sprayed or wiped with your bleach solution and allowed to air dry. Rinse the board in clear water before the next use to help remove residual bleach taste from the board.

  • Countertops. Clean them thoroughly then spray or wipe with bleach solution. Allow to air dry. If there is a residual "frost" from the bleach, it may be wiped off with a clean cloth.

  • Dishrags, towels, sponges, and scrubbers. These tend to be highly contaminated. You shouldn't use a sponge in the kitchen. Use a clean dishcloth daily. After use, rinse thoroughly and air dry. If you use the dishcloth for wiping the floor or wiping up after pets or any general cleaning, send it to the laundry and get a clean one. Scrubbers (metal or plastic) should be washed in the dishwasher each time you run it. If you do not have a dishwasher, rinse them thoroughly to remove any visible food residue and soak them in your bleach solution for 10 minutes.

  • Garbage disposals. The film that builds up on the inside of the disposal is teeming with bacteria. Use a long-handled angled brush and a chlorinated cleansing powder to scrub the inside walls of the disposal and the underside of the rubber splash guard. Allow the cleanser to remain in place (don't rinse) until the next time the disposal is used. This gives the chlorinated disinfectant time to kill the bacteria. This should be done at least once a month. CAUTION: Make sure the disposal is off and cannot be turned on during this procedure.

  • Sink drains and P-trap. Before going to bed, pour one cup of hot water into the drain. Wait a minute for the drain to absorb heat from the water then pour in one cup of chlorine bleach (undiluted). Allow to stand overnight. This should be done every 1 to 2 weeks. Not only will this help sanitize the drain and keep odor down, but it will also help keep the drain running freely.

  • Refrigerators. The fridge should be periodically cleaned thoroughly. After cleaning, it should be wiped with your bleach solution and the food replaced. Spills should be cleaned up immediately. Food should not be allowed to mold or decay in the refrigerator.

  • Complex appliances, such as food processors, blenders, and eggbeaters. The dishwasher remains the champion for cleaning these items. Visible food materials should be removed from crevices, recesses, or tight areas and the washable parts of the appliances placed in the dishwasher.