Enjoy Outdoor Activities, but Avoid Ticks to Help Prevent Disease

(Cheyenne) — While the Wyoming Department of Health encourages residents to enjoy outdoor activities, one important consideration this time of year is avoiding ticks and the diseases they may carry.


Diseases often transmitted by infected ticks in Wyoming include tularemia, Rocky Mountain spotted fever (RMSF) and Colorado tick fever (CTF). Rocky Mountain Wood Ticks (Dermacentor andersoni) are the most abundant in Wyoming, but there are also plenty of American dog ticks (Dermacentor variabilis) and a few Brown dog ticks (Rhipicephalus sanguine us), according to health department researchers in Cheyenne.


The Rocky Mountain Wood Tick, female on the left and male on the right.

“Tick populations usually peak during the spring and summer months of May, June and July,” said Emily Thorp, surveillance epidemiologist with the Wyoming Department of Health. “When we walk through, play or sit in brushy and grassy areas or handle animals, we can be exposed to ticks.”


Recommendations to help avoid ticks include:


* Wear light-colored clothing to make it easier to see ticks crawling on clothing.

* Tuck pant legs into socks.

* Apply insect repellents such as those containing 20 percent or more DEET and/or picaradin.

* Upon return from potentially tick-infested areas, search body for ticks and remove if found.

* Parents should check their children for ticks, especially in the hair.

* Check pets for ticks; veterinarians can recommend tick control products.


Tularemia, also known as “rabbit fever” or “deer fly fever,” frequently affects rabbits, hares and rodents and has been associated with rabbit die-offs. Other mammals can also become infected.  In addition to tick bites, people may acquire tularemia when bit by infected deer flies or horse flies. It can also be transmitted by handling infected animals, or through ingestion or contact with untreated, contaminated water or insufficiently cooked meat.


Added precautions to help reduce tularemia risk include:


* Avoid bathing, swimming or working in untreated water and avoid drinking untreated water.

* Avoid handling rabbits, squirrels or other animals that appear sick.

* Wear rubber gloves when skinning animals, especially rabbits and squirrels; skin animals in a well-ventilated area.

* Wash hands thoroughly with soap and water after handling sick or dead animals.

* Cook meat thoroughly before eating, especially rabbit and squirrel.


Tularemia symptoms can include fever, swollen and painful lymph glands, inflamed eyes, sore throat, mouth sores, skin ulcers and diarrhea.  If the bacteria are inhaled, symptoms can include abrupt onset of fever, chills, headache, muscle aches, joint pain, dry cough and progressive weakness and pneumonia.  Initial RMSF symptoms may include fever, nausea, vomiting, muscle pain, lack of appetite and severe headache.  Later signs and symptoms may include rash, abdominal pain, joint pain and diarrhea. RMSF patients often require hospitalization. Colorado tick fever usually causes fever, headache, muscle and joint pain, and, occasionally, a rash.


From left to right, engorged ticks from least to most.

“While we may not see high case numbers with these diseases, they can be quite serious. We suggest anyone who becomes ill after an insect or tick bite or after handling a sick or dead animal should contact a medical professional,” Thorp said.


In 2011, one tularemia case was reported to the Wyoming Department of Health. In 2010 there were three cases, including one that was fatal. In 2011 there were nine RMSF cases and no CTF cases reported.


Tick-borne diseases are confirmed through physician-ordered blood tests. Healthcare providers should report any suspected or confirmed cases of tick-borne disease by calling 307-777-8634.