Friday Funny: If I Can’t Touch The Door Knob, How Do I Get In The Building?

Posted by Heidi Schwartz

Door knob with spikes.

Despite what has been said about telephones, keyboards, and restrooms (and even Blarney Stones), it turns out that one simple item—the door knob—is apparently the germiest thing in most public buildings. These are the findings of University of Arizona microbiologist, Dr. Charles Gerba (also known as “Dr. Germ”), who recently presented the results of his research to the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), an infectious disease meeting of the American Society for Microbiology.

His research team found that contamination of just a single door knob or table top could result in the spread of tracer viruses throughout office buildings, hotels, and health care facilities. Within two to four hours, the virus could be detected on 40% to 60% of workers and visitors in the facilities and commonly touched objects.

“We actually put a virus on a push plate in an office building of 80 people. The building had three entrances. Within four hours, the virus ended up on over half the people’s hands and surfaces that people touched in that building. What we really learned was the hand is quicker than the sneeze in the spread of disease,” he said during the meeting.

And once people enter the buildings, the first thing they do is spread the germs to areas that experience a high degree of public traffic.

“What’s the first thing you do when you go to work? You get a cup of coffee. You want to be the first one in that coffee break room. Every time you touch these surfaces you’re picking up between 30% and 50% of the organisms on that surface,” Gerba explains.

Dirty door knob drawing.

There is a simple solution, though, he says. “Using disinfecting wipes containing quaternary ammonium compounds (QUATS) registered by EPA as effective against viruses like norovirus and flu, along with hand hygiene, reduced virus spread by 80% to 99%.”

In the intervention phase, cleaning personal and employees were provided with QUATS disinfectant containing wipes and instructed on proper use (use of at least once daily). The number of fomites on which virus was detected was reduced by 80% or greater, and the concentration of virus was reduced by 99% or more.

There are 90 different EPA-registered QUAT-based formulations available under 1500 different brand names that are formulated to kill norovirus on solid surfaces. These are available as wipes or ready-to-use liquids or concentrates for use by professional maintenance teams.

“The results shown that viral contamination of fomites in facilities occurs quickly, and that a simple intervention can greatly help to reduce exposure to viruses,” says Gerba.