Tularemia is a rare infectious disease that can attack the skin, eyes, lymph nodes, lungs and, less often, other internal organs. Often called rabbit fever or deer fly fever, tularemia is caused by the bacterium Francisella tularensis. The disease mainly affects mammals, especially rodents, rabbits and hares, although it can also infect birds, reptiles and fish.
Tularemia spreads to humans through several routes, including insect bites and direct exposure to an infected animal. Highly contagious and potentially fatal, tularemia usually can be treated effectively with specific antibiotics if diagnosed early.