If you've ever cringed when a colleague coughs and sneezes at their desk, you were right to be wary of catching their cold, according to a new study that found germs spread around offices at lightning speed.
Researchers from the University of Arizona say sick people should stay at home because germs spread faster around the office than first suspected –– with co-workers facing a 40 to 90 percent increased risk of infection if their colleague is sick at the office.
When one person comes to work sick, more than 50 percent of commonly touched surfaces, such as lift buttons, office fridge handle, telephones and desks are likely to be infected with the virus by midday.
But the good news is, regularly using hand sanitiser and washing your hands can reduce the risk of spreading germs between colleagues.
Related: How to protect yourself from germs
The US scientists studied an office of 80 people, and put water droplets on some people's hands, and put droplets on one person that had artificial viruses that mimicked cold, flu and stomach bug germs.
Related: Germs in public places
The participants went about their morning as usual, but by lunchtime, the researchers found that more than half of the surfaces and the employees had picked up at least one of the viruses.
"We were actually quite surprised by how effectively everything spread," said study author Associate Professor Kelly Reynolds.
"There weren't a lot of people roaming around –– they basically go in their offices, sit in their chairs and are on their computers. They may go to the bathroom, and they have a common kitchen area they share and a photocopier, but that's about it."
The cold and flu germs had a relatively short-lived survival time, and had disappeared by the end of the workday. However the stomach bug had spread to infect 70 percent of the surfaces.
"We really felt that the hand was quicker than the sneeze in the spread of disease," said study co-author Charles Gerba.
"Most people think it's coughing and sneezing that spreads germs, but the number of objects you touch is incredible, especially in this push-button generation. We push more buttons than any other generation in history. The key message is to stay at home when you're sick."
The researchers then repeated the study but dished out hand sanitiser, tissues and disinfecting wipes to the employees. They were also instructed to wash their hands before lunch and after meetings with lots of people.
"Using tissues to wipe your face, using hand sanitiser or having it available for use, and washing your hands before lunch and after a big meeting resulted in an 80 percent reduction across the board, for all three viruses, in their risk of infection," Reynolds said.
Professor Robert Booy, an infectious diseases expert at the University of Sydney, told ninemsn he would like to see further research into how likely office-workers are to contract viruses from surfaces.
"This study shows very good evidence that people coming to work with an illness can easily spread it all through their environment," he said.
"But they did not show the co-workers were actually getting infected, they just showed that there was contamination of the environment. It would be nice to see a follow-on study that addressed what the risk is to workers, as opposed to risk of surfaces becoming contaminated."
Professor Booy said coughing and sneezing near somebody remains the most powerful mode of contamination.
"Even if you can find the viruses on surfaces, they are in relatively low number and may not infect you," he said.
"Whereas if someone coughs and sneezes right close up to you, you are going to get a much bigger load of the virus. That remains an important way of spreading disease. We want to discourage people from coming to work with a sniffling nose and coughing and sneezing."
Dr Ronald McCoy, from the Royal Australian College of Practitioners, told ninemsn Australian workers need to prioritise washing their hands.
"Most of these sort of infections are usually caused when the germ goes from hands to the mouth and nose," he said.
"The germs rest on things, people touch those things and that gets onto the hand and that goes into the mouth –– this is why hand-washing is so effective."