And they travel quickly, according to a study from the American Society for Microbiology. Researchers placed a sample of a harmless virus on a single doorknob or table-top in an office building. The first area that was contaminated was the coffee break room, says study researcher Charles Gerba, a microbiologist at the University of Arizona. Within two to four hours, the virus could be detected on 40% to 60% of workers, visitors and commonly touched objects.

Poor hygiene from office workers can exacerbate to this, too: a 2019 UK survey showed that only 61% of UK office workers washed their hands properly with warm water and soap after going to the toilet.

A virus in the air

Dirty fingers and desks are one thing, but the biggest risk for the spread of virus is what’s travelling through the air.

“The great risk is not from the [office] building but from sick employees,” says Dr Ali Khan, an epidemiologist and professor at the College of Public Health UNMC at the University of Nebraska. “If one person is sick, he or she could spread the germs through coughing and sneezing, touching surfaces and contacting others closely. Even staying at their private desks, germs can also be spread by the flying droplets which settle on any surface and cause contamination”.

The circulated air of offices can also contribute to the spread of microbes. Hewitt says that in indoor environments, microbial life is circulated through the air and within HVAC systems.

“Maintenance of systems and filtration has an impact on how contaminants flow through the air, so buildings that have not been properly serviced to maintain appropriate circulation, filtration, humidity and temperatures can contribute to higher amounts of microorganisms moving through the systems,” she says.

Just keep washing

The home offices in which so many of us are now working are more controlled environments with fewer people and fewer touched surfaces, says Lisa Ackerley, a chartered environmental health practitioner and deputy chair of International Scientific Forum on Home Hygiene. You won’t be surrounded by all of the shared places colleagues are touching or exposed to their droplets, nor will you have to be leery of their poor hygiene contributing to the spread.

But, if you head outside you can still bring the virus into your home while working remotely if you’re not diligent. “The virus cannot spontaneously grow in your home. It must be brought in by an infected human,” says Khan. That means coming in contact with someone who is sick or touching an infected surface, then transferring it to your surfaces at home.