Bacteria and viruses often lurk in “hot spots” you’d never expect

Viruses that cause colds and flu can often be found in places that many people would never suspect. This is also true of other harmful microbes, such as methicillin-resistant Staphylococcus aureus (MRSA) bacteria, and bacteria, including Escherichia coli and salmonella, that cause foodborne illness.

What you may not know: It’s been estimated that about one in three Americans are carriers (and transmitters) of staph bacteria — usually in amounts so small that no infection occurs in the carrier.

Since it’s impossible to completely avoid dangerous microbes, one of the best ways to stay healthy is to be aware of germ “hot spots” — including ones that often are overlooked, such as…

  • Telephone receivers (and cell phones), TV remote controls, computer keyboards and copying machines. Most of us know to wash our hands after touching public doorknobs or handrails, but we may not consider the microbes on telephone receivers (and cell phones), TV remote controls and computer keyboards in public places, at work or even in our own homes.

    Other areas to be wary of include the control buttons on office copying machines, handles of communal coffeepots, elevator buttons and shared books or tools.

    It’s best to assume that any inanimate surface — such as Formica, stainless steel or even paper — that could have been touched by another person may be infected with viruses or bacteria. If you touch your mouth, nose and/or eyes (the body’s main entry points for infectious organisms) after touching the infected surface, you will be exposed to the germ.

    Cold viruses and many bacterial infections are primarily transmitted by such surface contact. Flu viruses — including the H1N1 and seasonal flu — tend to be transmitted through the air (via coughs and sneezes) but also can be passed through surface contact.

    What you may not know: Since bacteria and cold and flu viruses can survive for up to several days on inanimate surfaces, you can be exposed to germs long after the infected person has contaminated the area. Scientists have estimated that 80% of all human infections are transmitted via hand-to-hand or surface contact.

    Self-defense: After touching inanimate surfaces (such as those described earlier) in a public place — or at home, if someone in your household is sick — wash your hands thoroughly with plain soap for 20 seconds under running water. Then dry them thoroughly with a paper towel or air dryer.

    Or apply hand-sanitizing gel containing at least 62% alcohol, such as Purell Instant Hand Sanitizer or Germ-X, as soon as possible after touching such surfaces.

    If someone in your home or office is sick: Each day, clean surfaces that are touched by others with a cleansing wipe or other product (such as those made by Lysol or Clorox) that is registered with the Environmental Protection Agency (EPA) — check the product label for an EPA registration number. This means the product can be used as a disinfectant. Or simply squirt alcohol-based hand sanitizer on a paper towel and wipe the surface.

    Important: Use wipes and gels that kill bacteria and viruses. These broader-spectrum cleansers are sometimes labeled “antimicrobial” — not “antibacterial.”

  • Paper money. A  Swiss study found that some strains of flu virus can survive on paper money for up to three days — and for up to 17 days when mixed with mucus.

    In addition, a University of California researcher cultured 68 $1 bills and found that all but four had colonies of dangerous bacteria, including the variety that cause staph infections and pneumonia. Coins tend to have lower levels of bacteria and viruses — perhaps because they contain trace metals that help inhibit such microbes.

    Self-defense: To reduce your exposure to germs, use credit or debit cards in place of paper currency as often as possible during daily transactions, and wash your hands with soap or use a hand sanitizer after touching paper money.

  • Doctors’ waiting rooms. Studies have found that germs are transmitted at a particularly high rate in the waiting areas of doctors’ offices — especially by touching countertops, pens and even magazines.

    Self-defense: As much as possible, avoid touching shared surfaces (such as those described above), and wash your hands immediately after your doctor visit.

    If hand-washing is inconvenient, keep hand sanitizer in your pocket or purse and carry your own pen to sign papers at doctors’ offices and stores.

  • Pets. An increasing body of evidence shows that dogs — and cats, especially — carry MRSA bacteria. It’s believed that these animals are exposed to the germs by human carriers and that the bacteria contaminate the animals’ coats, skin and saliva, where it can then be transmitted to other animals and people. MRSA bacteria can, of course, infect humans, but it also can make cats and dogs sick.

    Important new finding: A recent random study conducted at the University of Guelph in Canada found that 2% to 3% of dogs carry MRSA bacteria. Meanwhile, in a study of 35 homes, researchers at Simmons College in Boston found that people who have cats in their homes are eight times more likely to have MRSA bacteria on household surfaces than those without household cats.

    Self-defense: Wash your hands or use a hand sanitizer after touching your pet… make sure any cuts or abrasions you may have are covered with a bandage before touching an animal… do not let pets lick your face… wash pets’ food and water bowls in a sink separate from the one used to prepare your own food… and wear gloves whenever touching an animal that has an open wound.

  • Microwave ovens, countertops and salt and pepper shakers. Most of us know that we need to clean kitchen faucet handles and sinks, sponges and cutting boards to avoid exposure to foodborne microbes. However, some surfaces tend to be overlooked, such as microwave oven controls — which are touched frequently, often while users are handling raw food — and countertops, which are high-contact areas for raw food. Research shows that salt and pepper shakers also are likely to be contaminated.

    Self-defense: Immediately after preparing any raw food — including fruit and vegetables as well as meat, fish or poultry — wipe down any surfaces you may touch (such as microwave controls, countertops and salt and pepper shakers) with antimicrobial cleanser, or use a mixture of one part household bleach diluted in 10 parts water. Apply the cleanser with paper towels or disposable rags. If you use sponges, put them in the dishwasher each time you run it — or rinse, then microwave them for one minute at high power several times a week. Do not place sponges that contain metal fibers in the microwave.

  • Bathroom sink handles. In one survey of the homes of 30 adults with colds, bathroom sink handles were identified as the place most likely to harbor traces of cold virus.

    Self-defense: If anyone in your family has a cold or flu — or any other respiratory, skin or gastrointestinal infection — clean bathroom sink handles (as well as other potentially contaminated objects, such as doorknobs and light switches) at least once daily with antimicrobial cleanser.