- an infectious disease characterized by high fever, pains in joints, bones, and muscles, and a cutaneous eruption, caused by rickettsii and transmitted by ticks: first reported in the Rocky Mountain area, but now more widely distributed.
- an acute rickettsial disease characterized by high fever, chills, pain in muscles and joints, skin rash, etc. It is caused by the bite of a tick infected with the microorganism Rickettsia rickettsii
