Singer-songwriter Christopher Cross has been diagnosed with the coronavirus. The five-time Grammy winner shared the news in a lengthy Facebook post on Friday (April 3).

"I'm sorry to report that I am among the growing number of Americans who tested positive for the COVID-19 virus," he wrote. "Although I am fortunate enough to be cared for at home, this is possibly the worst illness I've ever had."

The musician, whose songs "Arthur's Theme (Best That You Can Do)" and "Sailing" topped the Billboard Hot 100, urged his fans to take the growing global pandemic seriously.

"For those of you who still do not believe the COVID-19 virus is real, or think it is a 'hoax' or part of some conspiracy, my advice to you is to understand right now that this is a deadly illness spreading like wildfire throughout the world," he continued. "PLEASE make every attempt to stall the spread of the virus."

After sharing a few tips on how people can help flatten the curve -- including "follow the SCIENCE" and a link to the CDC's page about the coronavirus -- he concluded his note with a reminder. "Wherever you are in the world, let's all be kind to one another," Cross wrote. "Only if we work together can we defeat COVID-19."

Since the spread of the coronavirus, there are more than one million known cases worldwide, and nearly 56,000 deaths. Multiple celebrities have spoken out about contracting and recovering from the virus; several musicians have also died due to complications from COVID-19.