Hot, dry weather in the Midwest has created the perfect conditions for mosquitoes that carry West Nile Virus.
The Culex mosquito breeds in still-damp ditches and underground storm water basins.
Indiana, Ohio and Illinois are reporting higher rates of infected mosquitoes compared with past years. More infected mosquitoes means a higher West Nile risk for humans. Illinois and Oklahoma report earlier-than-usual cases of human infection.
What's more, the dry weather means the pesky floodwater mosquito is scarce. That makes people think mosquitoes aren't a problem and gives the Culex mosquito a chance to sneak up and bite.
Health officials urge people to wear insect repellent though they may not be noticing biting mosquitoes.