Rocky Mountain spotted fever is an acute infectious disease caused by the virus-like organism Dermacentroxenus rickettsii, which is transmitted to human beings by an infected tick. The infection is characterized clinically by an acute onset with chills and fever, severe headache, restlessness, delirium and a characteristic hemorrhagic eruption of the skin. The histopathologic picture of the early stage of this cutaneous manifestation is a proliferation of the endothelial lining of the small blood vessels followed by necrosis of the endothelium and of the smooth muscle of the media. Later, typical manifestations of phlebitis, thrombosis and gangrene may be present.
DISTRIBUTION AND CARRIERS
Rocky Mountain spotted fever, recognized for half a century in the Rocky Mountain states, can no longer be considered as limited in distribution to the Rocky Mountain states area because the Public Health Reports1 show a total of 2,190 cases occurring in thirty-seven of the forty-eight states