Encyclopedia Home / R / Rocky Mountain spotted fever

Rocky Mountain spotted fever

  • Definition

    Rocky Mountain spotted fever is an infectious disease brought on by a specific type of bacteria carried by ticks.


    Alternative Names

    Spotted fever


    Causes, incidence, and risk factors

    Rocky Mountain spotted fever is caused by Rickettsia rickettsii (R. Rickettsii), which is carried by ticks. The bacteria spread to humans through a tick bite.

    In the western United States, the bacteria are carried by the wood tick, and in the eastern U.S. it is carried by the dog tick. However, other ticks spread the infection in the southern U.S. and in Central and South America.

    Contrary to the name "Rocky Mountain," most recent cases have been reported in the eastern United States, including North and South Carolina, Virginia, Maryland, Georgia, Tennessee, and Oklahoma. Most cases occur in the spring and summer with about 1,000 cases reported per year. Most of the reported cases have been in children.

    Risk factors include recent hiking or exposure to ticks in an area where the disease is known to occur. The bacteria is unlikely to be transmitted to a person by a tick that is attached for less than 20 hours.