Wednesday, October 1, 2014

Germs at the Office

It’s almost that time of year when you ever-so-slowly inch away from the person with the hacking cough and infectious sneeze.

Turns out it’s pretty hard to avoid the germs of your co-workers, even the ones you don’t know personally. Just one door contaminated with a virus spreads the germ to about half the surfaces and hands of about half the employees in the office within four hours, according to a study at the University of Arizona, in Tucson. Germs traveled through the office just as quickly when the researchers infected a single person with the artificial virus.

“The hand is quicker than the sneeze,” said Charles Gerba, a professor of microbiology at the University of Arizona who presented the research at the Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington D.C. earlier this month.

The University of Arizona researchers conducted their study at an office building with 80 employees. They contaminated a push-plate door at the building entrance with a virus called bacteriophage MS-2. It doesn’t infect people yet is similar in shape, size and survivability to common cold and stomach flu viruses.

Within two hours, the virus had contaminated the break room—coffee pot, microwave button, fridge door handle—and then spread to restrooms, individual offices and cubicles. There, researchers found, the virus had heavily contaminated phones, desks and computers. By four hours, they found the virus on more than 50% of the commonly touched surfaces and on hands of about half of the employees in the office.

“It was amazing because most of these people didn’t know each other,” said Dr. Gerba. The studies, funded by Kimberly-Clark Corp. , the Irving, Texas, maker of consumer brands including Kleenex and Huggies, are currently under review for publication. Dr. Gerba has worked on science-advisory boards and as a paid consultant for a number of companies including Kimberly-Clark.

In an intervention, the Arizona researchers then gave about half of the employees hand sanitizer and disinfectant wipes to use. After the intervention, detection of the virus on people’s hands went from 39% to 11%.

The results were similar in an experiment in which the researchers infected a single employee with a droplet containing an artificial virus that didn’t cause illness. Within four hours, half of the commonly touched surfaces in the office and the hands of half of the employees were infected with at least one virus.

Studies indicate the average adult brings their fingers to the nose, mouth or eyes about 16 times an hour. For children ages 2 to 5, the number is as many as 50 times an hour.

The researchers calculated that employees had a 30% chance of infection, said Kelly Reynolds, a microbiologist and associate professor at the University of Arizona who worked on the studies and has been a consultant for companies, but not Kimberly-Clark.

Germaphobes, don’t freak out. Just because you are exposed to a virus or bacteria, doesn’t mean you will get sick. Microbiologists say much depends on the dose, or number of virus particles that you are exposed to, whether you’ve been exposed to the germ before and your overall susceptibility and health.

Many people have devised low-tech methods of avoiding germs. Eloise Laird, a 51-year-old mother of three who lives in Dallas, says her weak immune system forced her to become a germaphobe. She carries her own pen and refuses to touch elevator buttons.

“I use my elbow or knuckle in the elevator, just not my fingertips,” Ms. Laird, a former corporate chief financial officer, says. She keeps a paper towel in her hand as she opens the door in any public restroom.

“I don’t know who uses their hand to open doors anymore when they leave the bathroom,” Ms. Laird says.

Different viruses have different life spans, and they also are dependent on factors such as temperature and the material where they are harboring. Some viruses are more infectious than others.

“Our body harbors viruses all the time,” said Martin J. Blaser, director of the Human Microbiome Program at New York University’s Langone Medical Center. “The average person has trillions of bacteria and dozens of virus species living in us. You can do studies where you can show that germs move around, but does that mean it’s a health hazard? Generally not.”

Dr. Federico Laham, a pediatric infectious-disease specialist at Arnold Palmer Hospital for Children in Orlando, Fla., says some viruses, like the norovirus, the most common cause of infectious diarrhea, are superinfectious, while others may be less contagious, or more difficult to catch.

Studies conducted at daycare centers have found 30% to 40% of children without symptoms have respiratory viruses on them, Dr. Laham says.

Dr. Reynolds, of the University of Arizona, says pathogens have survival rates ranging from seconds to months. Most respiratory viruses can survive a maximum of two to four days, she said. Survival is heavily dependent on environmental conditions such as temperature: Some viruses die at high temperatures.

Material also plays a role. Microbes on porous surfaces, such as carpeting and upholstery, have better survival rates on synthetic fibers like polyester than on cotton. Pathogens are readily transferred on stainless-steel surfaces, although certain metals, such as copper, tend to have an antimicrobial effect and germ survival there probably won’t last more than a few hours, Dr. Reynolds says. Microbes have comparatively good survival on plastic or Formica. And anything with textured grooves or connection points, like a keyboard or a child’s toy, will have a tendency to collect dirt, which can help survival.

While the University of Arizona researchers believe the use of hand sanitizers and disinfecting wipes can sharply reduce the spread of viruses, not all experts agree.

NYU’s Dr. Blaser says he generally doesn’t recommend hand sanitizers and disinfectant wipes because they kill good bacteria, which can help protect against bad bacteria. Exceptions, he says, are in hospitals and during flu season.

“In our desire to get rid of bad bugs we’re also getting rid of good bugs,” he says.

Some researchers suggest one way to slow the spread of potentially harmful germs would be to eliminate a social norm—the handshake.

A study published this year in the American Journal of Infection Control found a handshake can transfer from 10 to 20 times as much bacteria as a fist bump. Studies have found only 40% of hospital employees wash their hands adequately, leading some doctors to suggest that handshakes should be banned in hospitals.

The University of Arizona researchers have conducted experiments in hotels, schools and health-care facilities. In a study published this year in the journal Food and Environment Virology, they found that infecting one hotel room with the virus led to the infection of nearby rooms. They speculated cleaning tools, like mops and towels, spread the germs. The virus also spread to the conference room. The study was also funded by Kimberly-Clark.

The next stop for the researchers is more detailed studies in public restrooms. Dr. Gerba said they want to contaminate a public restroom and see where and how far the virus travels.

Source; Wall Street Journal WSJ