Case Report Form Questions and Answers Suggested Reading External Links Glossary Natural History Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. In the case of Rocky Mountain spotted fever, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii .
Ticks transmit the organism to vertebrates primarily by their bite.
Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces. After the eggs hatch, each stage must feed once to develop into the next stage. Both male and female ticks will bite. A female tick can transmit R. rickettsii to her eggs in a process called transovarial transmission. Ticks can also become infected with R. rickettsii while feeding on blood from the host in either the larval or nymphal stage.