The incubation period (time from tick bite to onset of illness) ranges from about 1 to 14 days.
The most common symptoms of Colorado tick fever (CTF) are fever, chills, headache, body aches, and feeling tired. Some patients have sore throat, vomiting, abdominal pain, or skin rash.
About half of patients have a “biphasic” fever. This means they have several days of fever, feel better for several days, and then have a second short period of fever and illness.
Most people who become ill have mild disease and recover completely. However, weakness and fatigue may last several weeks.
In rare cases, some patients may develop more severe illness that affects the central nervous system with symptoms that include stiff neck and confusion.
Life-threatening illnesses or deaths due to CTF virus are rare.
There are no medications to treat CTF virus infection.
If you think you or a family member may have CTF, see your healthcare provider.
Persons with severe CTF illnesses may need to be hospitalized. Treatment may include intravenous fluids and medications to reduce pain and fever.
People who have CTF should not donate blood or bone marrow for 6 months after their illness. The virus may stay in red blood cells for several months and can be passed to others by blood transfusion or bone marrow transplant.