Hidden germs: Where illness-causing bacteria lurks

11:51 PM, Nov 11, 2010   |    comments
  • Share
  • Print
  • - A A A +

SLIDESHOW: Which item has the most bacteria?

SACRAMENTO, CA - Before the flu season really kicks in, there are some things you might want to keep in mind. More of us carry digital devices and rely on them 24/7. And, we're touching screens more often--- iPhones, Droids, GPS, iPads. Those devices and much of the office equipment everyone shares at work can harbor lots of germs and bacteria.

Consider this:

These are the numbers of germs of certain surfaces:

Cell phone: 25,000 germs per square inch

Desktop: 21,000 germs per square inch

Computer keyboard: 3,300 germs per square inch

Toilet seat: 50 germs per square inch.

(Source: Dr. Charles Gerba, PhD microbiologist with University of Arizona-- in a study funded by Clorox Co.)

Going viral

600: The number of times a day most people touch their face -once or twice every two minutes.

3: Women's offices harbor nearly three times more bacteria than men's offices. That's probably because women eat at their desks more.

4: Men's wallets are four times more "germy" than purses.

200: The number of colds most people get in their lifetime. That equates to about five years of congestion and coughing.

45: How many times a day the average cold sufferer blows her nose during the first three days of a cold. She uses 20 to 30 tissues daily.

(Source: Ah-choo!: The Uncommon Life of Your Common Cold-by Jennifer Ackerman. Quoted in Allure Magazine, November 2010)

The concern:

If you touch a screen, 30 percent of any virus that might happen to have taken up residence upon it will end up on your fingertips. It then may go from your fingers to your eyes, mouth or nose and cause infection. That's according to a study published by the Journal of Applied Microbiology. You could contact more germs from sharing iPhones than if someone sneezed directly in your face.

British researchers say that a cell phone has 18 times more bacteria than a flush handle in a typical men's restroom.

MSNBC has reported that cell phones carry 500 times more bacteria than a toilet seat.

Why and how?

According to the British study, cell phones are a technological petri dish for tens of thousands of germs. The reason germs and bacteria are appearing on our touchscreen devices is because germs multiply in warm places. Microbiologists say that phones generate heat. We've got germs on our faces, hands, and in our mouth. All together, it's a bacterial breeding ground.

"I think they are just hanging out and waiting to go someplace warm and moist where they can grow," said Dr. Susanne Lindgren, a microbiologist at Sacramento State University.

Charles Gerba, a microbiologist at the University of Arizona, tested 25 cell phones and found that staph bacteria was growing on almost half of them. The staph bug which can cause everything from skin infections to meningitis.

Other bacteria found on cell phones include: Staphylococcus aureus, E. coli, klebsiella, salmonella, streptococcus, and acinetobacter.

Many other surfaces can be subject to the spread of bacteria and germs. A dollar bill, elevator buttons, a hand rail, ATM machines, a steering wheel, the bottom of a purse, keyboards.

News10's lab test

News10 swabbed more than a dozen surfaces for traces of bacteria, E. coli, and coliform.

Among the surfaces tested: cell phones, laptops, touchscreen devices, money, and a purse. We also swabbed a men's restroom including the toilet seat and the flush handle.

RESULTS: Which surfaces contained the most bacteria?

None of the surfaces, including the men's restroom, showed traces of E. coli which Lindgren found surprising.

But many of the petri dishes showed colonies of bacteria.

"You can't, just from looking at a petri dish, necessarily know if this is something that's going to make you sick or not because we have a lot of good bacteria out there that will show up on these plates," said Lindgren. "Most of what I see look like normal bacteria flora from our hands and to me, are not worrisome."

A closer look showed the top three surfaces tested with the most bacteria were a MacBookPro laptop keyboard, followed by a flip phone, and then the men's restroom -- both the toilet seat and flush handle.

The touchscreen devices--including an iPhone, GPS, and iTouch, along with a Blackberry, were further down the list when it came to concentrations of bacteria. Those results were contrary to the British study.

"If you compare the iPhone to the men's room handle, they (the bacterial growth on the petri dishes) look about the same. However, if you compare these other touchscreens (the growth from the touchscreens), much less," said Lindgren.

According to Lindgren, we could not determine what specific type of germs were on the surfaces we tested. We also couldn't see traces of flu viruses. That would have required more testing than what we had time to do.

However, Lindgren identified what was found on two of the surfaces. Swabbing the inside of a purse and a dollar bill showed similar results. Both test plates displayed bacillus, a soil-born bacteria. That's most likely because the dollar was left loose inside the purse instead of being kept in a wallet. Testing the bottom of the purse showed more traces of bacillus and fungii.

The amount of bacteria present truly depended on the owner, the user, and the item, said Lindgren.

The Solution

Some studies indicate that certain germs can live up to two days. One medical expert said the flu virus could survive on a dollar bill for up to 17 days. But most germs die within a few hours.

Especially during the flu season, doctors recommend that you wash your hands often. Lindgren said you should be washing your hands with warm water and soap for at least 17 seconds, "which is singing 'Happy Birthday' twice."

Wipe your cell phone and keyboard daily with a disinfectant wipe to get rid of bacteria and viruses. Disinfect office equipment that many people share, like telephones or copy machines. 

Try not to share personal devices like your cell phone. If you are worried about germs or bacteria growing on your phone, Motorola has come up with an anti-microbial coating for some of its phones.

Women should avoid putting their purses on the floor, and they should carry money in a wallet so the rest of their handbag is not infected.

More tips 

Germ quiz

POLL: How germ-phobic are you?

Related Article: Germ Test Results: Which has the most bacteria?


by Suzanne Phan, sphan@news10.net

Twitter: @suzannephan

Facebook: SuzannePhanNews10

News10/KXTV

Most Watched Videos