Amazon.com Inc. and Facebook Inc. on Thursday joined Microsoft Corp. in recommending employees in the Seattle area to work from home after several people in the region were infected with the coronavirus.

Seattle in Washington state has been most affected by the virus in the United States. Ten people have died out of 39 cases of infections through community transmission of the virus.

Amazon (AMZN), which is headquartered in Seattle, recommended employees in the area to work from home through the end of the month, after an employee tested positive for the coronavirus on Tuesday.

The employee worked at Amazon's South Lake Union office complex in Seattle. Two other company employees in Milan, Italy, were also infected.

Facebook (FB) said on Thursday a contractor at its Seattle office was diagnosed with the coronavirus and that it would shut the location until March 9.

"A contractor based in our Stadium East office has been diagnosed with the COVID-19," a company spokeswoman said in an emailed statement.

The companies' work from home recommendation will affect more than 100,000 people in the Seattle area, as both Microsoft and Amazon employ over 50,000 each. Facebook has more than 5,000 employees in the area.

Seattle health authorities have urged companies to allow their employees to work from home as much as possible, stagger shifts to ease commuter congestion on public transportation and avoid large work-related gatherings.

The epidemic has shown no signs of slowing, with deaths mounting globally. It has killed more than 3,000 people worldwide, mostly in China, where it originated in December.

Big tech companies have also been dropping out of several conferences and calling off corporate events as the virus spreads. Apple (AAPL) and Netflix (NFLX) on Wednesday dropped out of SXSW conference to be held later this month, citing virus concerns.

Microsoft (MSFT) said on Wednesday that some "essential" employees should continue to go to their work locations and that the company would follow government guidelines for disinfecting its sites for essential personnel.