Everyone knows that viruses spread fast. But just how fast? According to a study, viruses can spread to 40 to 60 percent of the population in a building in just two to four hours.

Presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy, the study used a tracer virus to track down the spread of contamination called bacteriophage MS-2. This tracer virus was chosen because it closely resembles the human norovirus in size, shape, and level of resistance to disinfectants. It won't make people sick though so it was safe to unleash in a heavily populated building.

To carry out the study, Charles Gerba of the University of Arizona, Tucson and his colleagues placed the tracer virus on a couple of commonly touched surfaces like a table top and a door knob at the start of the day in a health care facility, conference room, and office buildings.

The researchers then sampled 60 to 100 fomites, or surfaces with the capacity to carry infectious organisms like bed rails, push buttons, sink tap handles, coffee pot handles, phones, light switches, and computer equipment, at different intervals. After just two to four hours, it was revealed that up to 60 percent of the sampled fomites were already contaminated by the tracer virus. If this wasn't a study, that means majority of surfaces would already be crawling with the norovirus.

Is a norovirus infection really a cause for concern?

It should be, with the norovirus being the most common cause for acute gastroenteritis in the country, according to the Centers for Disease Control and Prevention. Every year, the virus leads to 19 to 21 million cases of illnesses, translating to between 56,000 and 71,000 instances of hospitalizations and up to 800 deaths.

Most people steer clear of those who sneeze and cough but the truth is viruses are most commonly transmitted by touch, with infections most commonly acquired after touching a surface or object with the norovirus.

But while it is true that contamination was shown to easily spread, it can also just as easily be prevented. As it turns out, using disinfecting wipes with quaternary ammonium compounds recognized by the EPA is effective at keeping viruses like the flu and norovirus at bay. 

When cleaning personnel were instructed to use disinfecting wipes, results showed that contamination was cut by at least 80 percent on the fomites and that the tracer virus was reduced by at least 99 percent.

"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," explained Gerba.

Aside from using disinfecting wipes, proper hand-washing is advised as well, most especially after using the toilet and before handling food.