An acute viral infection
transmitted by the bite of the tick Dermacentor andersoni,
Colorado Tick Fever is also called Mountain tick fever,
Mountain fever and American mountain fever.
The disease is limited to
the western U.S. and is most prevalent during March to September,
especially in May and June. The incubation period is 3 to 6 days.
Symptoms of fever continue for 3 days, then abate and recur 1 to 3
days later for another few days. Risk factors are recent outdoor
activity and recent tick bite. The incidence is high in Colorado,
where up to 15% of regular campers show past exposure (based on
antibodies). It is much lower throughout the rest of the U.S.