Once a virus makes it onto an office doorknob, it only takes a few hours before it can be found on 40 to 60 percent of the people inside a workplace -- as well as 40 to 60 percent of other commonly-touched objects, like an elevator button or printer -- according to famed germ scientist Charles Gerba, Ph.D., of the University of Arizona, Tucson. Luckily, it’s just as easy to halt the spread of a virus, thanks to a few well-placed hand sanitizers and disinfectant wipes.
Gerba arrived at his conclusions after conducting a novel study in which he actually planted “tracer viruses" -- meaning viruses that are not harmful to human health, but resemble those that are -- inside offices and then measured how fast and how far they spread. He then provided workers with what he labeled "weapons in germ warfare": alcohol gel sanitizers and disinfectant wipes, along with instructions for proper use.
Even though only half of the workers committed to using these sanitizing products, the number of surfaces and objects containing the virus decreased by at least 80 percent once they were employed. What's more, when Gerba re-contaminated the offices as part of a later phase of his experiment, the concentration of the virus itself was reduced by more than 99 percent.
“Things that we recommend, like hand sanitizers, hand washing, disinfectant wipes and disinfectants do their job,” said Gerba in a live-broadcast presentation on Monday at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy. “By doing these kinds of virus release studies, and looking at where viruses accrue, we can get a more precise idea of the benefits of these types of weapons of germ warfare.”
The virus Gerba used, known as MS-2, infects bacteria but is not dangerous to humans. But MS-2 has a similar shape, size and and resistance to other viruses like the norovirus, which causes acute gastroenteritis and is responsible for some 21 million illnesses, 70,000 hospitalizations and 800 deaths a year, according to the Centers for Disease Control and Prevention. Norovirus can live for days or even weeks on hard surfaces and may be resistant to some disinfectants, notes the CDC.
In one particular experiment, Gerba put the tracer virus on the doors of an office with 80 people and found that in three hours, MS-2 could be detected on over half of the office population’s hands, as well as over half of the surfaces people touched in the building. One room in particular was a “hotspot” for the virus, noted Gerba.
“What we learned was, the first area to be contaminated was the coffee break room,” said Gerba. “That actually turned out to be a hotspot, because a lot of people go in there — more of a hotspot than the restroom.”
In the second phase of that experiment, Gerba educated office workers about the proper use of alcohol gel sanitizers and disinfecting wipes with quaternary ammonium compounds, which are usually used in health care facilities to guard against infectious diseases. He installed a hand sanitizer in the break room and instructed workers to clean their desk once a day with the wipes.
Then Gerba re-released the tracer virus into the office (and into the newly-educated workforce) and found his interventions overwhelmingly halted the spread of MS-2.
“'Make it convenient’ is what we really went for,” said Gerba. “I’m sure a lot of people who were involved or said they would use a hand sanitizer or disinfectant also participated because it was there and made available to them.” Gerba repeated the study several times and in different offices so that his infection risk data could approach statistical significance.
In another experiment that was part of the study, Gerba “infected” hotel rooms with tracer viruses and found that they were passed from room to room on the cleaning cloths of housekeeping services. In the future, he plans to contaminate the public restrooms of a facility with a tracer virus to see how and where it spreads throughout the office building.
“We know that the bottom of women’s purses pick up bacteria from restroom floors,” said Gerba about his past research on the subject. “We want to see: Will that move a virus around an office or could people take it home?”
Gerba presented an abstract of his research at the annual infectious disease meeting of the American Society for Microbiology in Washington, D.C.