Colorado Tick Fever
(CTF)
Definition
Colorado tick fever is an infection that is spread to humans by the bite of an infected tick.
Colorado tick fever is transmitted through the bite of an infected tick.
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Causes
Colorado tick fever is caused by the Colorado tick fever virus. Humans can get the virus through the bite of an infected tick. The Rocky Mountain wood tick is the main carrier of the Colorado tick virus in the US. This tick can be found in the western US states (not just in Colorado). It can be found in areas above 5,000 feet in elevation.
The virus is also carried by other small mammals, including ground squirrels, porcupines, and chipmunks. There have been reports of rare cases of Colorado tick fever caused by exposure in a laboratory setting and a blood transfusion.
Risk Factors
Risk factors include:
- Living or traveling in mountain forest areas at altitudes above 5,000 feet in the western US states (eg, Colorado, Utah, Wyoming, Idaho, Montana, Oregon)
- Being in these areas between April and July
Symptoms
If you have any of these symptoms, do not assume it is caused by Colorado tick fever. These symptoms may be caused by other, less serious health conditions. Symptoms usually appear 4-5 days after a tick bite occurs and may last for three weeks:
- High fever
- Chills
- Severe headache
- Pain behind the eyes
- Sensitivity to light
- Muscle pain
- Lethargy
- Abdominal pain
- Vomiting
- Nausea
- Rash