US mosquito decline prompts warning as West Nile cases rise

Fewer mosquitoes are being seen in much of the Western and Midwest U.S.—down about 50% this year, with some states reporting up to 70% fewer—thanks to a historic drought linked to climate change. But West Nile virus is hitting the U.S. with a 22-year high, with around 143 cases and five deaths so far, as drought concentrates mosquitoes and birds around shrinking water sources, increasing transmission risk; scientists warn populations can rebound as conditions shift and emphasize ongoing surveillance and control measures.