Researchers show where germs are hiding in the workplace -

Researchers show where germs are hiding in the workplace

HOUSTON—By far one of the most common places to catch the flu or cold is your workplace.  Add to that: a recent study of public restrooms by Michigan State University found that 95 percent of people don’t wash properly, 33 percent don’t use soap and 10 percent don’t wash at all.

So what are the germiest places at work?  We decided to check our own workplace at KHOU 11 News.

Folks are always “on the go,” especially in a big city newsroom.  There are lots of people on the run and eating on the run.  All that means germs get the run of the place.

So KHOU 11 News asked microbiologists from UT Health to help us find the germiest places in our office. Researcher Doug Litwin showed up with cotton swabs and Petri dishes lined with nutrient agar (stuff that mimics the human body and that bacteria love).

“So what are we going to swab first?”  Litwin asked.

We directed him to the refrigerator, a leading germ suspect in just about any place. 

The graduate student at The University of Texas Graduate School of Biomedical Sciences hit the fridge, a food counter used 24-7, high-traffic touch areas such as a printer, a keyboard, a telephone, the bathroom sink and floor, and for fun we snuck a swab at Morning Show Traffic Reporter Katherine Whaley’s computer mouse. 

All told, we collected 12 samples and shipped them to UT Health Medical School for incubation.  In 20 hours, our samples had bloomed.

The University of Texas Health Science Center at Houston (UTHealth) Medical School Associate Professor and Microbiologist Dr. Heidi Kaplan gave us the official results. 

The No. 1 offender was the bathroom sink in the men’s room.  It was worse than the second-place winner, our nasty office fridge.

Why were these places the top-ranked locations for bacteria? 

“They grow well in wet moist areas,” Dr. Kaplan explained.

What were the next biggest culprits?

The phone was No. 3., Katherine Whaley’s mouse was No. 4, Dr. Kaplan said.

Interestingly, the cleanest place we swabbed was the newsroom door handle.  It was No. 12.  (See below for full ranking of germiest places.)

Bacteria and viruses typically live on unwashed hands only briefly, some for just a few minutes. By contrast, they can survive up to three days on hard plastic surfaces.

More problematic, is how long a person is contagious after showing signs of a cold or flu.  Generally you are contagious for five days, even if your fever and symptoms are gone.  The contagion period is even longer for kids, and up to two weeks for folks who are immune compromised, such as transplant patients, HIV/AIDS patients and diabetics.  Students returning to school and workers returning to their jobs may still put others at risk.

“You may be feeling better, but you may be able to transmit the flu virus to people you work with or your family,” Dr. Kaplan said.

But microbiologists emphasize that most bacteria are actually good for you. 

“In large part, they can protect you from some of the bad bacteria that is around,” Dr. Kaplan said.

The correct hand washing technique is to use soap and wash for 20 seconds. In a University of Arizona study, researchers put tissues, hand sanitizer and disinfecting wipes at each person’s desk, with suggestions, but no requirements of use.  They found that reduced risk of infection by 90 percent.


Results of Swab Test for Bacterial Growth

Nov. 13, 2013

Performed by: Heidi B. Kaplan, PhD Associate Professor and Doug Litwin, Graduate Student, UT-Health Medical School at Houston, Department of Microbiology and Molecular Genetics

Purpose: To determine which are the most bacteria covered surfaces at the KHOU studio and in a family home.

Experimental Design:

Sterile swab is wet with 1X sterile phosphate buffered saline (PBS) solution.

Swab is used to wipe various surfaces at KHOU studio and Bish family home.

Swab is used to cover the surface of a Brain Heart Infusion (BHI) agar plate and labeled.

Plates are incubated at 37°C overnight.

Overnight growth on one plate is recorded every minute for 20 hours.

After overnight incubation colony forming units (CFU) are counted/estimated for each plate.

Some of the colonies are streaked onto Blood Agar and MacConkey plates for quick phenotypic analysis by Clinical Microbiologist, Audrey Wanger, PhD.


Results:  List of places from most growth to least growth

KHOU Studio

1. Bathroom sink

2. Refrigerator bottom shelf

3. Phone – mouth and ear piece

4. Katherine Whaley computer mouse

5. Bathroom floor

6. Xerox machine keypad

7. Production studio keypad

8.  Counter top

9. Printer

10. Phone – back of handle

11. Microwave door handle

12. Main studio door handle


What do you think are the germiest places in your office? Click here to take the interactive quiz.

You can also see which workplace items are the germiest on the KHOU 11 mobile app.

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