By Illinois Radio Network

SPRINGFIELD – Human West Nile cases in Illinois are down significantly this summer.

As of Wednesday, 33 people are sick with West Nile. Dr. Jennifer Layden, the chief medical officer at the Illinois Department of Public Health, said that’s down from about 90 at this point last year.

No one in Illinois has died from West Nile in 2017.

Layden said a cool August is probably the biggest reason why cases are down this year.

“This August happened to be the 12th coolest on record,” Layden said. “We know that West Nile activity, in the mosquito that predominately carries it, really does better in the hot and dry weather.”

Last year, 155 people got sick, and six people in Illinois died from West Nile.

Layden said the early fall is typically when human West Nile cases peak. So, she said, still wear bug spray and long sleeves if you’re going to be out where mosquitoes are common at dusk or dawn.

“As it becomes cooler, West Nile activity will slow,” Layden said. “Typically, it’s not really till the first hard freeze that we think the season is at an end.”

Illinois’ peak year for West Nile was 2002. That year, 884 people got sick and 67 people died.