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Infectious Germs: Where They Love to Hide

Germs Where You Least Suspect Them

Your hands may be the easiest vehicle for germs to enter your body.

Everyone knows there are germs around them. Some of the places are obvious—you probably wash your hands after cleaning up your cat’s litter, changing a diaper, or using the toilet. But there are places in your home that probably escape your attention, and some of those places need to be cleaned as frequently as germ hot spots you already know.

The easiest way for germs to escape their hiding places and find their way into your body is through your hands. Your hands are constantly interacting with objects in your home, and they’re also what you use to wipe your eyes and nose, and to feed your mouth. That’s a common way for infectious diseases to escape your body’s main natural defense—your skin.

In the following article, learn the environments where germs love to hide. You and your family can enjoy fewer colds and other infections as well as a healthier daily life by learning these germ-filled locations and cleaning them frequently.

Your Smartphone

One of the most germ-filled objects in your home is your smartphone.

How many times a day do you check your smartphone? One study found that people swipe, tap, type, and click over 2,600 times a day on average. That adds up to over 75 separate phone sessions for the average user.

Now ask yourself—when’s the last time you cleaned your smartphone? Most people never even think to clean them. But with all of that touching, your phone has become a breeding ground for various bacteria, and some are quite dangerous. The risk to health care workers who deal with infectious diseases is great, but everyone is susceptible.

One study found that of 150 cell phones, 124 showed bacterial growth. Among the most common bacteria recovered belong to the family Staphylococcus, some varieties of which can cause Staph infections. And remember where else your cell phone ends up—these devices touch your face, your ears, and your lips. The danger of spreading disease increases when you share your phone with someone else. This can lead to cross-sharing diseases.

To avoid this danger, read your phone manufacturer’s instructions on the proper way to clean the device. Many phones can be kept clean by wiping them down with rubbing alcohol, but check the instructions first to make sure this method is best for your phone.

The T.V. Remote

Watch out for snacking as you watch TV.

As you channel surf, your fingers are dancing across a germ danger-zone that rarely gets cleaned. All those button presses are opportunities for germs to come into contact with your skin. And if you’re one of the many people who eat while they watch, your fingers are then potentially transferring germs onto the food you eat. That gives bacteria an easy route directly into your body, leaving you vulnerable to sickness.

The safest way to veg out on television is by keeping your remote controls wiped down. You can make a habit of it. Add it to your list when you do another common chore, such as picking up or sweeping. By doing that, you can begin to associate a clean house with a clean remote. Then when the munchies strike while you watch, you can snack more safely.

Your Laptop and Keyboard

When's the last time you cleaned your laptop or keyboard?

Your hands can be constantly at work while you use your computer. And you should be paying attention to the places your hands frequent, such as the mouse and keyboard. Always wash your hands before eating, and don’t let them come into contact with unclean spaces while you eat. If you’re concerned that your home electronics aren’t as clean as they should be, start adding them to your cleaning routine to keep bacteria at bay.

But your cleaning regimen shouldn’t end there—make sure your desk is sanitized as well. One study found more than 20,000 bacteria per square inch on desk surfaces. That’s more than six times the number found on the average keyboard and more than 400 times the number found on the average toilet seat.

The Sink Sponge

Kitchen sponges can't be cleaned in a microwave very effectively.

It’s surrounded by soap and warm water while you use it, but think about how much time your kitchen sponge spends being damp and warm. That’s exactly the type of environment bacteria love, because it allows them to multiply quickly. And that’s particularly concerning if you cook with raw meat. Raw chicken, for example, is an infamous carrier for Salmonella, the world’s most common source of food poisoning.

This problem has been known for a while. In the past, health experts have recommended boiling or microwaving sponges to get more use out of them. But further study has shown these methods only partially effective, removing at most about 60% of the bacteria that collects on used sponges. That means the weaker bacteria are killed off, leaving room for the stronger ones to set up residence. So, the safest way to keep your dishes clean is by throwing your used sponge away after a week of use. This is especially important if you live in a home with someone who is especially young or old, or otherwise living with a compromised immune system.

Trouble on Your Toothbrush

We don't know how harmful the bacteria on your toothbrush actually are.

The dentist says you should use it at least twice a day, or once after every meal. What other object spends so much time in your hands and mouth but the tooth brush? Tooth brushes should be replaced at least every three to four months according to the American Dental Association, but in the meantime, they can collect a whole host of germs.

We don’t know how harmful bacteria on your toothbrush are, just that they exist. Your mouth harbors hundreds of microbes that usually balance each other out, preventing one microbe from taking over. Some of them wind up on your toothbrush and its bristles, studies have shown. But while we don’t know how much danger these bacteria pose, there are ways to reduce your risk of becoming infected:

  • Don’t share your toothbrush. If the person you share with is sick, this is an easy way for disease to spread. And just because you can’t tell the person is sick doesn’t mean they aren’t. Many infections set in before symptoms arise, including the common cold.
  • Rinse your toothbrush with tap water, and leave it upright to dry.
  • Don’t let your toothbrush touch another toothbrush while it is stored.
  • Don’t cover or seal in your toothbrush. This prevents it from drying as quickly, leaving more time for bacteria to flourish.
  • Become aware of how soon you need to replace your toothbrush, and stay on schedule. While most adults can get away with replacement after three or four months, tooth brushes for children often should be replaced more frequently than that.

The Whole Office Lounge

How much bacteria sits on the surfaces at your workplace lounge?

Blame your coworkers (and yourself). One way for infectious diseases to spread is through the various break room objects that are touched frequently. How often are the buttons on your vending machine cleaned? What about the communal coffee pot and that container of half-and-half? Think about all the surfaces that many people are using every day—refrigerator handles, cabinet doors, microwaves and more can all serve as homes for germs.

The best way to keep yourself safe is to wash your hands frequently. Make it the last step you take after filling your water bottle or preparing your lunch. And rinse that coffee pot after you use it! They can become moldy or full of yeast when they aren’t cleaned frequently.

Your Dog and Puppy’s Chew Toys

Some of the nasty bacteria dogs have in their mouths include Salmonella.

Ever hear the idea that your dog’s mouth is cleaner than yours? Don’t believe the hype. Researchers in Japan studied the bacterial plaque from 66 dogs and 81 humans. They found that both human and dog mouths are teeming with bacteria, just not of the same kind. They further found that many of these bacteria are highly transferable, meaning that close contact with doggy germs can upset the bacterial balance in your own mouth. These transferable bacteria include some nasty pathogens, including E. coli, Salmonella, and Campylobacter, all of which can cause gastrointestinal infections.

All of this means that some germs belong in your dog’s mouth, but not your own. By letting your pups lick your face, you’re inviting more than affection—unhealthy organisms may manage to set up a new home on your body, particularly inside your mouth.

One of the ways this transfer can take place is through chew toys. Your dog may love to wrestle with them, and you may find yourself touching them as well while cleaning up your dog’s area or in order to play fetch. If that’s the case, you will want to make sure your hands are well-scrubbed before touching them to your face.

Cold, Hard Cash

Cash can harbor infectious germs.

We may be moving in the direction of a cash-free economy, but today cash is still an important and popular means of buying and selling. Scientists have studied how often a bank note changes hands. They call this the “velocity of money.” It turns out that physical bills change hands about 55 times a year on average before they are worn out and retired. That number is more than double for smaller notes worth less money.

When a dollar bill changes hands, microbes are commonly carried with it. Fecal bacteria, mold, and yeast are some of the common hitchhikers that make their way onto cash money. In fact, according to a study commissioned by the U.S. Air Force, 94% of $1 bills harbor bacteria. U.S. bank notes seem to be more at risk than some others, too. Bills issued by the U.S. Treasury are made of 75% cotton and 25% linen, and seem to be more attractive to bacteria than the currency of some other countries like Australia and Canada that use polymers instead.

Cash is everywhere, and you probably use it all the time. So, if there’s no easy way to avoid its use, the best tip for staying healthy is to wash your hands before you eat or otherwise touch your face. It could keep you from spreading sickness while you spread your money around.

That Old Office Coffee Cup

Cleaning your cups is important, even if you only use them now and then.

Germs seem to like certain surfaces more than others. Soft, porous materials at the right temperature can send growth rates soaring for bacteria and viruses alike. But even hard, nonporous surfaces can spread disease. Enter the coffee cup.

You may not see the point in washing your office coffee cup between uses. But a coffee cup is exactly what researchers used to study the spread of rhinovirus, the virus responsible for the common cold. They found that by having study subjects touch an infected coffee cup, and then touch their eyes and nostrils, about half came down with colds. The good news is that cleaning these surfaces dramatically improved the odds of avoiding infection. So, keep that coffee mug clean to prevent sickness.

The Laundry Washer and Dryer

Be careful not to infect yourself as you clean clothes.

We toss our dirty clothes in the laundry to get the dirt out, along with all those nasty germs. But does it work? According to one study, it depends on how you clean. The study found that some disease-causing pathogens can survive the washer and dryer. These include rotavirus, the bug responsible for spreading the common cold.

So how should you clean to keep diseases out of your clean clothes? If your clothes can stand it, wash them hot. Also, make sure to use bleach for suitable clothes. Few pathogens can withstand the combination of hot water and bleach. And when you wash especially filthy items such as rags, dish towels, and clothes worn by anyone with an infection, be sure to use water heated to 140 degrees. Finally, remember that the bacteria from your dirty clothes tends to accumulate in your appliances. To keep them away, run them on a regular cycle now and then with bleach and water, but no clothes.

Your Purse/Handbag

Germs love to hide inside purses.

You may be carrying more home inside your purse than you meant to. Your purse goes where you go—to the public restroom, the floors of restaurants, and everywhere else. One study found that one in five purses and handbag handles contains bacterial contamination great enough to pose a threat to health. In a separate study, a microbiologist swabbed 50 purses and found that one in four tested positive for E. coli, which produces a harmful toxin that can cause severe stomach cramping and diarrhea.

To keep away from harmful bacteria, be sure to clean your handbag regularly. A Clorox wipe will work just as well as soap and hot water, and may be easier on the fabric. If the surface you set your purse on is damp, be sure to wipe it down when you get home—bacteria love damp places. And for your safety and the safety of those around you, refrain from setting your handbag down on surfaces where people eat. All of this applies equally to similar items, such as backpacks and briefcases.

ATMs and POS Keypads

Hundreds of hands pass over ATM keypads each day.

Automatic teller machines and point-of-sale (POS) keypads are an easy pick for a list of hidden germ hideouts. Think about all the fingers that touch them every day. In busy places like New York City, hundreds of people visit these machines on any given day.

Researchers tested dozens of ATMs from across New York City to find out what microbes cling to these cash machines. They found remnants of human skin, traces of food, and microbes that came from household surfaces. Bacteria were plentiful, and the same types of microbes were found, no matter the ATM’s location.

If you shook hands with 100 people in a day, you’d probably want to wash your hands before you ate. The same principle applies with ATMs and checkout keypads. Using one is similar to touching the hands of several people at once when it comes to germs. So, after visiting the bank, supermarket or any location that provides these machines, make sure your hands are clean before touching your face.

The Grocery Cart

How many germs do you pick up when you touch a grocery cart?

When’s the last time you pushed a grocery cart? Most people slide their hands all over these convenient carts while they push them through the store, and don’t give it a second thought. But just like most of the other items on this list, grocery carts see many hands every day, and if those hands carry infectious germs, you could be the next person infected.

One four-year study of grocery cart cleanliness frequently found everything from saliva, fecal matter, and mucus remnants attached to these carts. The study prompted new laws in some states like New Jersey that required or encouraged grocery stores to provide sanitary wipes to shoppers. If you’d rather stay healthy, use these the next time you go shopping, as such wipes can effectively reduce or eliminate many of the harmful pathogens you come into contact with.

The Soap Dispenser Itself

Who thought cleaning your hands could leave them with more germs?

Even when you’re trying to keep your hands clean, germs can find their way onto your skin. Public restrooms typically provide liquid soap from refillable dispensers to keep hands clean. But one study found that one dispenser in four harbors contamination. And it’s not the outside of the soap dispenser you need to be concerned about—the soap itself is contaminated, according to the study.

Not only did pathogens remain after washing from a contaminated dispenser, but study participants had actually increased the number of nasty germs on their hands after washing. So, what can you do to keep your hands clean? If the restrooms at work refill their soap dispensers, you can encourage the building manager to switch to sealed soap containers that can’t be refilled. You can also carry alcohol-based wipes or hand sanitizer with you to give your hands a more thorough cleansing after you freshen up at the sink.

The Towels in Your Kitchen

One of the grimiest items in your kitchen is the kitchen towel

One of the grimiest items in your kitchen is the same thing you use to dry your hands. That’s right—your kitchen towel is likely to be crawling with bacteria.

Researchers observed 123 parents between the ages of 20 and 45 to find out what really goes on in their kitchens. The subjects were asked to prepare two meals items—one with raw meat, and the other a fruit salad. The meat had been laced with a harmless but detectable bacteria so the researchers could study what items in the kitchen were most likely to be contaminated. After the test had been performed, the filthiest item in the kitchen was the hand towel. Why? It all comes down to hand washing.

The participants, 90% of them women, and more than 70% college graduates, rarely washed their hands effectively. And whether they washed too briefly or didn’t use any soap, most of them dried their hands on the towel. That left enough bacteria on the towels to raise concerns for the researchers. The results of the study showed that a full 90% of the fruit salads had been contaminated by bacteria from the raw meat.

What can you do about all of this? There are two things to keep in mind here. One is to replace your kitchen towel daily, or at least any day you cook in the kitchen. The second is to wash your hands properly, using soap, for a full 20 seconds each time you wash. Participants who did this were less likely to end up with contaminated kitchens.

Blowing Out Birthday Candles

Blowing on a birthday cake can spread a layer of bacteria across the frosting.

Sometimes sharing germs is socially acceptable—but it’s still gross when you think about it. One example is blowing the candles out of a birthday cake. How many partygoers think about the germs spread over a thick layer of icing after the special birthday guest puffs out the candles?

Scientists know bacteria live in your breath. Anywhere from 700 to more than 6,000 live bacterial cells escape your lungs every time you exhale. To find out how this relates to birthday cake, researchers built a fake cake by covering Styrofoam in foil and covering the foil in frosting. Candles were planted into the Styrofoam. After eating pizza, one of the participants blew out the candles and the frosting was carefully collected and compared to “cake” that hadn’t been blown on. Overall, blowing on the frosting increased bacterial growth by 14 times on average. But some gusty blowers can raise that to 120 times, and others seem to leave no additional bacteria on the frosting after they blow.

One of the study’s authors didn’t think it was anything to worry about. “If you did this 100,000 times then the chance of getting sick would probably be very minimal,” he said, explaining that even though bacteria were present, the amount is tiny compared to the number living inside your mouth at any moment. Also, most of these bacteria are harmless. Even so, if the blower is clearly sick, especially with the flu or a viral illness like a cold, you should probably skip that slice of cake.

Your Doorknobs

Door handles are often loaded with bacteria.

If you listed all the household chores you did regularly, would “clean the doorknobs” be on that list? Doorknobs see lots of hands from day to day, and they have been proven effective at transmitting disease.

Researchers studied how viruses can be transmitted in a typical office. They swabbed the office door with a harmless virus, and the hand of one random employee. Within four hours, half the office had been infected. A subsequent study of a larger number of offices and employees bore the same results—about half of an office stands to be infected by one germy door handle.

There are a couple of things you can do to protect yourself from the dreaded doorknob. One good idea is to carry disinfecting wipes or hand sanitizer, and use it after touching communal surfaces. Another is to avoid coming in to work when you know you are ill. Of course, the doorknobs in your home can’t be avoided when you’re sick, so be sure to wash your doorknobs frequently—infectious germs can be spread even before you show symptoms of illness.

Light Switches

Light switches are common sites of infection.

Turn on the lights, and you may unwittingly be turning on an infection. Light switches are another place hands frequently go, but disinfectants rarely visit. That’s been proven in a study of hotel rooms. Researchers looked at rooms to try and find their most germ-ridden hideaways. They found that light switches, particularly the ones on bedside lamps, pose a high risk of bacterial infection. In fact, the study found that the average light switch is crawling with bacteria. The average number of colony-forming units of bacteria on these switches per square centimeter? 112. It’s enough to make you want to break out the rubbing alcohol on your next vacation.

Your Cosmetics

Your makeup bag may be one of the germiest places around.

When you apply makeup, try to remember all the intimate places on your face that product will wind up. It’s second-nature for many to put on a little makeup in the morning and to reapply throughout the day, but if you don’t do so carefully, your fresh look can cause sickness.

With that in mind, here are a few tips to keep your makeup bag safe:

  • Don’t share. Even if your friend seems well, dangerous germs can still be spread.
  • Apply makeup with clean hands. If your hands aren’t clean, your makeup won’t be either.
  • Don’t wear makeup when you’re sick. You’re liable to preserve the disease-causing pathogens in the makeup itself, which can prolong your illness or cause you to get sick again later on.
  • Watch out for open sores and pimples. Any place where your skin is broken will not be as protected from infection, so avoid these areas as you apply your makeup.
  • Be wary of store samples. One study found yeast growing on three of 25 makeup samples, and that yeast can lead to pinkeye or rashes.

Hands and Germs

It may seem mundane, but hand washing is one of the best ways to fight infection.

Most of the hidden germ hotspots have something in common—they’re places where hands go over and over again. The simplest solution is to wash your hands properly, and at the right time.

How to Wash Your Hands

This might seem a little simplistic—even insulting. You learned to wash your hands as a child, right? Of course. But the truth is, most people don’t wash their hands properly. And that means infectious germs are getting a free pass.

The first step is to get your hands wet. Apply enough soap, and then lather. When you lather your hands, remember to get beneath the nails, between your fingers, and the backs of your hands. Next, scrub your hands for a full 20 seconds. To help you keep track of time, you can try humming the “Happy Birthday” song twice. Then rinse with clean, running water and dry. If you follow these steps, your hands will be safe from whatever germs they may have collected.

When Should You Wash Your Hands?

Knowing when to wash your hands is as important as knowing how. Anytime you’re preparing food or eating, you should wash your hands first. The same is true if you’re treating a wound or caring for a sick person.

You should also wash after doing any particularly dirty things. That includes petting animals, taking out the garbage, using the toilet, blowing your nose, and handling dirty diapers.

By keeping in mind when and how to wash your hands, you can dramatically reduce your risk of infection, no matter where the germs in your world are hiding.

Reviewed by Charles Patrick Davis, MD, PhD on 2/28/2018

Infectious Germs: Where They Love to Hide

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