It’s official: the first cases of coronavirus stemming from a corporate meeting have surfaced.

Biogen Inc. announced that three employees have been infected after attending a meeting in Boston last week. With 100,000+ cases of coronavirus worldwide (including now over 200 in the U.S. and over 160 in the U.K.), many big companies have are realizing the severity of the spread, and going to extremes to curtail the odds that their employees pick up the virus at work.

Splitting up employees, deep cleans, and mandatory work from home

Amazon (who confirmed one employee in Seattle tested positive), Facebook, Microsoft, and Google are all now asking employees in the Seattle area to work from home, following an outbreak in Washington state that has already reportedly claimed 10 lives, with 70 confirmed cases. Some are also amending interviewing processes, with Google conducting all interviews virtually, and Facebook and Amazon are altering interviewing processes to limit in-person meetings or put them on hold for now. Google also canceled its flagship developers conference, I/O, and has banned all international travel.

As the first case of coronavirus was confirmed in Oregon, Nike and Columbia conducted deep cleans of their facilities. Nike, “out of an abundance of caution,” said it closed its faculties for the deep clean, including all buildings, facilities, and even fitness centers, at the company’s world headquarters, according to Greg Rossiter, Nike’s global communications director, in an email.

Apart from deep cleans, other companies are increasingly encouraging employees to work from home. Twitter and Square (both under CEO Jack Dorsey) “strongly” encouraged their employees (some 9,000 people) earlier last week to work from home.

And on Friday, Facebook told its employees in the Bay Area to start working from home; the company also canceled all events in the Bay Area. “Based on guidance from Santa Clara County today, we are strongly recommending that all Bay Area employees and contingent staff work from home starting [Friday],” Anthony Harrison, Facebook’s company spokesperson, said in a released statement.

In the U.K., firms have been instituting some increasingly cautious measures to prevent a spread. UBS is requiring employees to fill out forms about their health, and banning employees or visitors from entering London offices if they have flu-like symptoms.

Still others like big-time hedge fund manager Greg Coffey are banning staff from using public transportation (the tube, in London), instead offering to pay for taxi rides to and from Kirkoswald Asset Management.

Meanwhile, HSBC evacuated the 10th floor in its Canary Wharf building, sending 100 people home and telling all employees in that building to work from home, after an employee was confirmed to have caught coronavirus. The bank has ordered a deep clean of the floor, which houses the bank’s research department.

Additionally, after an infected HSBC employee entered an S&P Global office, the company announced it were telling employees in its Canary Wharf office to work from home. “Following confirmation that a person who recently visited S&P Global’s offices at 20 Canada Square has been diagnosed with COVID-19, as a safety precaution we are have decided all S&P Global employees based in Canary Wharf should work from home until further notice,” S&P Global told Fortune in a statement. The company has about 1,200 employees in that office.

Other banks like JPMorgan Chase are starting to split up trading and sales employees in New York and London offices to reduce the impact on staff if coronavirus spreads to one of the offices. “Dividing our workforce into different locations improves our ability to serve clients continuously while reducing the health risks associated with physical contact should a case arise,” Marc Badrichani, who leads global sales and research, and Troy Rohrbaugh, the head of global markets, wrote in a memo to employees Thursday. Banks like Bank of America and Goldman Sachs are following suit, splitting up traders and sales employees (or planning to, respectively).

Others like Goldman Sachs, Citi Group, and Morgan Stanley are testing disaster recovery sites in London and the U.S., per the Financial Times, and are even going to measures like installing screens in traders’ homes. According to the report, Barclays is planning to split its trading floor staff into three groups, spread between its Canary Wharf headquarters, their own homes, and a back-up site at Northolt (near London).

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