Definition of Rocky Mountain spotted fever:

Rocky Mountain spotted fever is an infectious disease caused by bacteria carried by ticks.

Causes, incidence, and risk factors:

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

In the western United States, the bacteria is 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.