Chicago Detects First 2026 West Nile-Positive Mosquitoes as Human Cases Hold at 0
Updated
Updated · Block Club Chicago · Jun 12
Chicago Detects First 2026 West Nile-Positive Mosquitoes as Human Cases Hold at 0
3 articles · Updated · Block Club Chicago · Jun 12
Summary
West Nile-positive mosquitoes have been found in Chicago for the first time this year, the city health department said, while reporting no human infections so far.
June through October is the highest-risk period for mosquito transmission, and there are no licensed drugs or vaccines for West Nile, making bite prevention the main defense.
About 1 in 5 infected people develop fever and flu-like illness, while roughly 1 in 150 can become severely ill—especially adults older than 55 and people with weakened immune systems.
Chicago said its control program includes larvicide treatment of more than 80,000 catch basins, weekly mosquito testing, adult mosquito spraying and monitoring for human infections.