A single doorknob can contaminate up to 60 percent of people in a building in 4 hours

By Abby Phillip September 10 at 11:32 AM WashPost

Viruses can spread from a single doorknob to 40 to 60 percent of surfaces and people in a building in just a few hours, according to a new study.

Researchers put a tracer virus on one or two surfaces in a building (for example a doorknob or push plate) at the beginning of the day. And after two to four hours, the virus could be detected on a majority of commonly touched surfaces such as light switches, coffee pot handles, phones and computers.

"We actually put a virus on a push plate in an office building of 80 people, had three entrances, and within four hours it ended up on over half the people's hands, and it ended up on over half the surfaces that people touched in that building," said University of Arizona researcher Charles Gerba, who presented the study at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy on Monday.

"What we really learned was the hand is quicker than the sneeze in the spread of disease," Gerba said during his presentation.

(More here.)