Most frequent rickettsial disease reported in the US.
Caused by Rickettsia rickettsii
Obligate intracellular, gram negative bacteria
Predilection for vascular endothelial cells
Spread by ticks
American Dog Tick (Dermacentor variabilis) Most common vector<unk><unk>  Wood Tick (Dermacentor andersoni)
Brown Dog Tick (Rhipicephalus sanquineus)
Cayenne Tick (Amblyomma cajennense)
Seasonal distribution with most infections occurring in the summer months
Widely distributed in the US
States with the highest incidence are Oklahoma, Nebraska, Arkansas, Tennessee and North Carolina
Overall incidence is increasing while mortality is falling
Prior to the era of antibiotics, ~30% mortality
Currently mortality is 3-5%
Obligate intracellular, gram negative bacteria
Predilection for vascular endothelial cells
American Dog Tick (Dermacentor variabilis) Most common vector<unk><unk>  Wood Tick (Dermacentor andersoni)
Brown Dog Tick (Rhipicephalus sanquineus)
Cayenne Tick (Amblyomma cajennense)
States with the highest incidence are Oklahoma, Nebraska, Arkansas, Tennessee and North Carolina
Prior to the era of antibiotics, ~30% mortality
Currently mortality is 3-5%
Rocky mountain spotted fever
Other Tick Borne Illnesses
Rat bite fever
Non-specific viral illness
Chikungunya
Psittacosis
Crimean-Congo hemorrhagic fever
Anthrax 