08/27/2012 05:36 pm ET Updated Aug 27, 2012

Legionnaires' Outbreak Kills 2: Bacteria Traced To Chicago's J.W. Marriott Hotel

A bacterial disease whose origin was traced to a high-end Chicago hotel is responsible for eight infections and two deaths.

Health officials said Monday that two people have died of Legionnaires' disease after being exposed to the bacteria that causes it at the JW Marriott Hotel at 151 W. Adams St., the Chicago Sun-Times reports. Names of the victims have not yet been released.

Last week, the hotel issued a warning to all recent guests, and began the complicated process of notifying the 8,500 guests who stayed there from July 16 through Aug. 15 that they may have been exposed to the bacteria known to cause serious and sometimes fatal bacterial infections, ABC Chicago reports.

The bacteria, Legionella, spreads through the inhalation of contaminated water vapor, and can cause Legionnaire's disease, a severe form of pneumonia, Fox Chicago reports. Symptoms include headache, chills, chest pain and fever.

The disease often mirrors regular pneumonia, and can only be confirmed by a urine test, infectious disease expert Dr. John Segreti told CBS Chicago.

Dr. Kathy Ritger with the Department of Public Health told WBEZ that not all exposures lead to illness, but any recent guests experiencing respiratory problems should seek medical attention.

A hotline has been set up by Chicago Department of Public Health to answer questions from people who may have been exposed. That phone number is (312) 746-4835 during Monday-Friday from 8:30 a.m. to 4:30 p.m.