In the western U.S., the causative agent R rickettsii is transmitted by the wood tick , and in the eastern U.S., by the dog tick. Other ticks transmit the infection in the southern U.S. and in Central and South America. The incidence of infection is 8 out of 100,000 people. Most cases occur in the spring and summer with about 1,000 cases reported per year. The incubation period of the illness is from 2 to 14 days after the tick bite .
Symptoms usually start suddenly with a persistent fever .
A rash will appear 2 to 5 days after the onset of the fever. The risk factors include recent hiking or exposure to ticks in an endemic area. Rocky Mountain spotted fever Please read this Important notice . Please read it.