McHenry County Health Department officials said the individuals were hospitalized and diagnosed with the disease after staying at the hotel sometime between May 9 and June 4, the Arlington Heights (Ill.) Daily Herald reported Saturday.

The hotel's pool and hot tub have since been closed as a precautionary measure while the Illinois Department of Public Health conducts an investigation into the matter.

Legionnaires' disease is a form of bacteria that can easily be spread through inhaling a contaminated vapor or mist, the Daily Herald said.

The disease can prove fatal in some people, particularly those above the age of 65, and often shows symptoms similar to those of pneumonia.

The newspaper said, according to a public health news release, antibiotics are typically effective in battling the medical condition.