How dangerous is a wild baby house mouse?

How dangerous is a wild baby house mouse? - My husband rescued a baby house mouse a few days ago, it hadn't even opened it's eyes yet. I'm pregnant and worried about the diseases it possibly carries. (such as hanta virus and LCMV) He is convinced everything is fine but I am really not convinced. Is there any way to tell for sure if the mouse is infected? Can veterinarians test mice for things like this?

How dangerous is a wild baby house mouse?