2025 mosquito report shows Twin Cities saw record number of West Nile cases
The organization that monitors mosquitoes in the Twin Cities says the area saw the highest number of West Nile virus cases on record last year.
That's one of several highlights from the Metropolitan Mosquito Control District's inaugural annual report.
The MMCD said there were 47 human cases of West Nile in the Twin Cities last year, much greater than the previous high of 28. The rest of Minneota saw 75 cases throughout the year. A high number of the mosquito species that primarily transmits the disease and high infection rates among early mosquito pools contributed to the rash of cases, MMCD said.
The Twin Cities also saw the invasive Aedes aegypti species for the first time last year. Officials called the species' appearance "unexpected and concerning," but now believe they successfully eradicated the mosquitoes in the area. The MMCD will continue to surveil the species in 2026.
Cattail mosquitoes, which MMCD Executive Director Daniel Huff described as "aggressive," were out in record numbers in 2025 — the metro saw the highest reported population since 2020. Heavy rains in 2024 led to the boom.
Mosquito populations peaked the week of July 8 last year. Of the 20 weeks recorded by MCCD, seven saw population totals above the 10-year average, while the rest were below. There were 438 mosquito annoyance calls to the MMCD in 2025, less than a quarter of the total in 2024.
The MMCD treated nearly 282,000 acres for larval mosquitoes in 2025, the highest total in nearly a decade.
The MMCD covers seven counties — Hennepin, Ramsey, Anoka, Washington, Dakota, Scott and Carver.
