LARAMIE, Wyo. — Three mosquito pools in Albany County, just outside of Laramie, have tested positive for West Nile Virus, bringing the total number of counties in the state with WNV-infected mosquitos to three.
According to Hunter Deerman, Mosquito and Invasive Plant Management Supervisor at the Laramie Parks Department, the primary carrier in the city is Culex tarsalis.
His species prefers to prowl after dusk, making stragglers on the Laramie River Greenbelt Trail more vulnerable.
Mosquito surveillance traps set up around city limits discovered three distinct areas in the community to house these mosquitos, though the Laramie Parks release did not specify where. However, it stated that spraying for these pests would continue.
“Mosquito Control continues to perform targeted larval control and adult fogging operations to control vector mosquitoes in areas of higher vector densities, areas where citizens often recreate in the evening hours and in areas on the western edge of town where vector numbers are higher historically,” the park’s press release stated.
Already established rules prohibiting fogging in specific areas will be followed.
WNV-positive mosquitoes are not restricted to Albany County. According to data collected by the Wyoming Department of Health, mosquito pools in Laramie and Natrona counties tested positive for the same disease in 2025.
Pools in Laramie County have been tested the most frequently, with that county also housing the most pools of West Nile Virus–infected mosquitoes, at six. Albany County’s three positive pools rank it as the second-most infected county, while Natrona County’s two round out the bottom of the list.
Fremont, Teton, and Uinta counties have also been tested, but have yet to produce any positive results.
There have been no reported cases of the virus transferring to humans or animals in 2025.
Wyoming typically follows national human infection trends closely, with only a few human cases per 100,000 residents each year. However, 2023 stood out as a very active year for the West Nile Virus in Wyoming.
That year, the state deviated significantly from national trends, and four residents died.
In 2024, only one person, from Natrona County, died from the illness.
It remains to be seen what type of mosquito season Wyoming will experience this year. West Nile Virus is most active in humans in Wyoming during the warmest months of July, August, and September.
In preparation for those hotter, muggier and mosquito-ridden days, it is useful to know what signs to look for to detect West Nile Virus and what to do if a person suspects that they contracted it. For more information, see the Wyoming Department of Health’s page on the virus.
