Presidential candidate Mike Bloomberg is spreading awareness -- and maybe more -- at a campaign event in Virginia ... where he wiped his mouth and then put his hands all over the staff snacks!

Unclear what Bloomberg was picking at when he got hungry during the campaign event on Monday, but you can see him shove food in his mouth and then go back to the snacks with his unclean hand!

DON'T YOU KNOW THE CORONAVIRUS SONG?! (Seriously, it's a real song released in Vietnam instructing people how to protect themselves against the virus.)

But things go from bad to WORSE for Bloomberg ... who then sucks the crumbs off of all his fingers before going BACK to the snack bar!!!

In other words, this is a perfect example of how NOT to nosh if you care about your co-workers.

C'mon Mike ... use tongs next time.