To expand on Eric H's 5-3-2013 post (above): I was cleaning the results of a rodent infestation from my current project, feeling safe that there was no viable virus in these old droppings. I went to the CDC website to find that the virus only remains infectious in the environment for a few days, but they also point out you can't be sure that the critters weren't pooping in the radio moments before you pulled it out of the shed/attic/barn.
There have been less than a thousand reported cases in the U.S. since they started counting in 1993; but it has occurred in 34 states so far, the animal vectors are found in all 48 contiguous states, and about one third of the infections have been fatal.
The CDC recommends some rather extreme measures to deal with rodent droppings, but I think it would be prudent to leave a rodent-infested set outside of your living area for a week, and then clean as much as possible outside before taking it inside.