Colorado tick fever is an infection that is spread to humans by the bite of an infected tick.
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.
Colorado tick fever is transmitted through the bite of an infected tick.
Copyright © Nucleus Medical Media, Inc.
Factors that may increase your chances of Colorado tick fever:
- Living or traveling in mountain forest areas at altitudes above 5,000 feet in the western US (such as Colorado, Utah, Wyoming, Idaho, Montana, Oregon)
- Being in these areas between April and July
Symptoms usually appear 4-5 days after a tick bite occurs and may last for 3 weeks.
Colorado tick fever may cause:
- High fever
- Severe headache
- Pain behind the eyes
- Sensitivity to light
- Muscle pain
- Abdominal pain
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
Tests may include the following:
- Blood tests to identify the virus
- Blood tests to identify antibodies for the virus
- Other blood tests
There is no specific treatment for Colorado tick fever. Complications are extremely rare and include aseptic meningitis, encephalitis, and hemorrhagic fever. The fever and pain may be treated with acetaminophen and other pain relief medications. It is important to stay hydrated by drinking enough fluids. It is believed that immunity against re-infection occurs after exposure to Colorado tick fever.
To help reduce your chances of Colorado tick fever:
- Avoid tick-infested areas, especially during warmer months.
- Wear light-colored clothing to better locate a crawling tick.
- Tuck pants into socks when in tick-infested habitats.
- Use tick repellents.
- Regularly inspect and remove ticks from your body and your child’s body when in tick-infested habitats.
- Remove ticks using fine-tipped tweezers by grasping the tick close to the skin’s surface and pulling upward steadily.
- Disinfect tick bites with soap and water.
Centers for Disease Control and Prevention
National Institute of Allergy and Infectious Diseases
Colorado tick fever. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T115853/Colorado-tick-fever. Updated May 31, 2017. Accessed December 7, 2017.
Leiby DA, Gill JE. Transfusion-transmitted tick-borne infections: a cornucopia of threats. Transfus Med Rev. 2004;18(4):293-306.
Tick avoidance and removal. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T901539/Tick-avoidance-and-removal. Updated August 4, 2016. Accessed December 7, 2017.
Last reviewed November 2018 by EBSCO Medical Review Board David L. Horn, MD, FACP Last Updated: 12/20/2014