A worldwide disease caused by infection with the bacterium Francisella tularensis, which affects multiple animal species, including humans. Tularemia cases have been reported from North America, Europe, Russia, China, and Japan. In the winter, infection in adult humans occurs frequently from skinning infected rabbits, hares, muskrats, or beavers bare-handed; in the summer, infections occur in both adults and children from transmission of the bacteria through the bites of ticks or deer flies.