With warmer weather arriving, the Wyoming Department of Health (WDH) cautions residents and visitors that both mosquitos and ticks can spread potentially serious diseases in Wyoming.
Katie Bryan, a WDH epidemiologist, said mosquitos spread West Nile virus (WNV) when they feed on infected birds and then bite people, animals and other birds. Diseases passed on in Wyoming by infected ticks include tularemia, Rocky Mountain spotted fever (RMSF) and Colorado tick fever (CTF).
“Most people infected with West Nile virus do not realize it,” Bryan said. Among those who become ill, symptoms include fever, headache, body aches, skin rash and swollen lymph nodes. A very small percentage of those infected develop West Nile neuroinvasive disease with symptoms such as severe headache, fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions and paralysis.
Since WNV first appeared in Wyoming in 2002, reported human cases each year have ranged from two with no deaths in one year to 393 and nine deaths in another. In 2017, seven WNV cases were reported to WDH.
The “5 D’s” of WNV prevention include:
1) DAWN and 2) DUSK – Mosquitos that spread WNV prefer to feed at dawn or dusk, so avoid spending time outside during these times.
3) DRESS – Wear shoes, socks, long pants and a long-sleeved shirt outdoors. Clothing should be light-colored and made of tightly woven materials.
4) DRAIN – Mosquitos breed in shallow, stagnant water. Reduce the amount of standing water by draining and/or removing.
5) DEET – Use an insect repellent containing DEET (N, N-diethyl-m-toluamide). When using DEET, be sure to read and follow label instructions. Other insect repellents such as Picaridin (KBR 3023) or oil of lemon eucalyptus can also be effective.
“Tick exposure is common when we walk through, play or sit in brushy and grassy areas, or handle certain animals,” Bryan said.
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 sudden onset of fever, chills, headache, muscle aches, joint pain, dry cough and progressive weakness and pneumonia. Colorado tick fever usually causes fever, headache, muscle and joint pain, and, occasionally, a rash. 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.
Steps to help avoid tick-related diseases 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 self and children for ticks and remove if found.
Check pets for ticks; use tick control products recommended by veterinarians.
Tularemia, also known as “rabbit fever” or “deer fly fever,” frequently affects rabbits, hares and rodents and has been associated with rabbit die-offs. People may acquire tularemia when bit by infected ticks, 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.
Other tick-related illnesses such as Lyme disease or Powasssan disease can be a concern when residents travel to other areas but are not known to be spread in Wyoming. Zika virus, another mosquito-related disease, is spread to people mostly by certain types of mosquitos that do not live in Wyoming.
More information about WNV in Wyoming is available at https://health.wyo.gov/publichealth/infectious-disease-epidemiology-unit/west-nile-virus/
Learn more about Colorado tick fever, including how to remove ticks, at https://health.wyo.gov/publichealth/infectious-disease-epidemiology-unit/colorado-tick-fever/. Information about RMSF is available at
https://health.wyo.gov/publichealth/infectious-disease-epidemiology-unit/rocky-mountain-spotted-fever/. More details about tularemia are available at https://health.wyo.gov/publichealth/infectious-disease-epidemiology-unit/tularemia/