"I'm not in the habit of discussing medical issues on social media," Cross said Friday on Facebook and Instagram. "But I do so in hope this will help other people to understand how serious and how contagious this illness is."
The musician called the virus "possibly the worst illness I've ever had."
Cross implored his followers to self-quarantine, wash their hands frequently and avoid touching their faces to help stop the virus' spread.
"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," Cross said.