Well IF - and only if - you had reasonably forseeable exposure to hantavirus Andes variant, a mask would be a good idea.
If I was asked to see a patient with low blood oxygen and lung infiltrates who came off that cruise ship before it was quarantined and who just flew in from Cape Verde (or wherever they let people off) - yes, I would wear a mask.
This whole thing has quickly been turned into the latest fear porn by the liberal media.
My local lib TV news is starting their 12:00 reporting with it.
Just the latest attempt to keep the sheeple on edge.