Rare Game Spotted: Virus NES Dr. Mario Prototype?

Here’s a crazy looking game that I haven’t seen before.  On the surface, it looks like a prototype copy of what we now commonly know as Dr. Mario.  The game in this listing seems to be date 1989, which is a year before its release in 1990.  Digital Press seems to be working on this mystery as we speak.

In the meantime, this gem is up for sale on eBay here.  Here’s what the eBay seller Member idpeanutt42 says about the game in his listing:

I got this cart at the Mission Flea Market here in San Antonio. It was listed as Dr Mario but when I got home it says Virus.  It plays just like Dr Mario except there is a weird dog thing on the left side.  It is dirty but could be clean.  I lost one of the 5 screws in the back but there are still 4 more.