Breathing contaminated dust is the most common form of transmission.
Surveys have found the virus in deer mouse populations in Colorado, and in pocket, pinion and harvest mice in other areas. The deer mouse is commonly found throughout the Southwest. It is pale gray to deep red or brown in color with white feet and under side. Deer mice are active year around, but are more likely to move inside in the early spring and fall. Keep food and water, including pet food, out of rodent access.