CHICAGO, Ill. (WTVO) — The Centers for Disease Control and Prevention says 27 residents of Illinois have been infected with dengue fever as record-breaking levels of cases are spreading across the United States.

The CDC said 17 of the reported Illinois cases are in Cook County.

More than 9.7 million cases of the disease have been reported this year, more than twice as many reported in 2023.

Dengue is transmitted by infected mosquitoes and can cause nausea, vomiting, muscle aches, rash, joint and bone pain, and headaches.

There is currently no antiviral medication to treat dengue, but most cases subside within a week or two.

Dengue is most common in tropical environments. Florida is listed as the state with the most infections, with 210 reported infections.