CHEYENNE, Wyo. — The Wyoming Weed and Pest Council (WWPC) announced on Wednesday, June 5, that last summer’s mosquitos caused the worst outbreak of West Nile Virus (WNV) that the state has seen in more than a decade.
According to the Wyoming Department of Health, just three human cases of West Nile were reported in 2022. In 2023, Wyoming saw a sharp increase in the number of reported WNV cases. A total of 27 human cases occurred, an average of 4.8 cases per 100,000 people, which far exceeded the national average of 0.7. Four fatalities were also reported, the first WNV-related deaths in Wyoming since 2018. Animals, particularly horses, are also at risk of exposure with nearly 50 instances of equine-related WNV cases last year, an alarming increase from just a single case the year prior.
According to WWPC, this spring’s warmer weather accompanied by an increase in standing water due to melting ice and snow has created ideal breeding conditions for mosquitoes. Some species, like the Culex tarsalis mosquito, can spread WNV, and the WWPC is tracking the state’s mosquito population before adults begin hatching for the year.
“We try to identify the larvae and predict which adult mosquitos are going to emerge,” Assistant Supervisor for the Sheridan County Weed and Pest District Brian Songer said in the announcement. “By doing this, we can predict when we’ll start seeing adults and whether they are a simple nuisance or carry West Nile Virus.”
The WWPC offers tips for mosquito protection:
- Take time to minimize standing water sources on or near property.
- Protect from exposure to bites. Mosquito-proof or long sleeve clothing can be effective at keeping the bugs at bay, as can treating boots, pants and socks with EPA-approved repellant.
- Be sure to protect infants and children by covering their arms and legs.
- For horse owners, be sure to get horses vaccinated for WNV in the spring.
- Be on the lookout for the symptoms of West Nile Virus. According to the CDC, most people do not experience any symptoms. However, some people may experience a fever, headaches, joint pains, vomiting, diarrhea or rashes.
Contact a doctor if experiencing any symptoms related to WNV. Contact the WWPC if an animal is diagnosed to help guide surveillance and treatment efforts.
