Colorado Tick Fever: Symptoms, Diagnosis, and Treatment

Symptoms

The time from tick bite to onset of illness (incubation period) for Colorado tick fever ranges from about 1 to 14 days.

• The most common symptoms are fever, chills, headache, body aches, and feeling tired.
  • 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.
  • Some patients have sore throat, vomiting, abdominal pain, or skin rash.
• 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.
• Colorado tick fever rarely causes life-threatening illness or death.

Diagnosis

If you think you or a family member might have Colorado tick fever, talk to your healthcare provider.

• Healthcare providers diagnose Colorado tick fever based on:
  • Signs and symptoms
  • History of living in or traveling to an area where Colorado tick fever virus is known to circulate
  • History of possible exposure to the ticks that can carry Colorado tick fever virus
  • Blood tests
• Your healthcare provider can test for Colorado tick fever virus and other infections that can cause similar symptoms.

To learn more about testing, visit our Healthcare Providers page.

Treatment

• There are no vaccines to prevent or medicines to treat Colorado tick fever.
• Antibiotics do not treat viruses.
• Rest, fluids, and over-the-counter pain medications may relieve some symptoms.
• People with severe Colorado tick fever may need to be hospitalized for intravenous fluids and medicines to reduce pain and fever.

To learn more about treatment, visit our Healthcare Providers page.