The main method of transmission is when the virus enters the body by breathing contaminated air . This happens when fresh urine, droppings, or contaminated nesting material are stirred up and the virus floats in the air.
Tiny droplets become airborne and then can be breathed in.
Another way a person might get it is through rodent bites. But this is very rare. It is suspected that a person could get it if they touched a surface contaminated with rodent excretions and then touched their nose or mouth. This page last reviewed February 28, 2000.