Well, two posters have had the idea but didn't quite land on it. It isn't parvo- or hunta-, it's Hanta Virus. And this one nasty, often fatal repiratory infection (hence the reference about about using a dust mask when cleaning mouse droppings). It is found largely in the arrid southwest and researchers are finding that it has been around for a long time, but not recognized until recently.

See Disease vectors (it's a PDF) and Carriers and Vectors of Disease as starters. The second one is slow to load but has lots of photos for ID of your critters.

SRS