 People can develop permanent disabilities including "cognitive deficits, ataxia, hemiparesis, blindness, deafness, or amputation following gangrene".Ticks are the natural hosts of the disease, serving as both reservoirs and vectors of "R. rickettsii" Ticks transmit the bacteria primarily by their bites.Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.