DETROIT — State health officials are investigating numerous cases of tuberculosis exposure at four health care facilities in Detroit. The Michigan Department of Community Health said Thursday a healthcare worker who was unknowingly infected with TB worked last year at multiple hospitals. 

The MDCH says the worker was in contact with about 560 patients who received dental care between Aug. 1, 2013 and Dec. 17, 2013. The worker has not been identified but is receiving treatment and is not at work. Co-workers and patients who have been in close contact with the individual have already been notified. 

The affected Detroit health care facilities are:

Detroit Medical Center: 450 patients exposed, 888-362-2500

Henry Ford Hospital: 10 patients exposed, 313-874-7733

St. John Hospital Medical Center: 23 patients exposed, 313-343-3311

University of Detroit Mercy School of Dentistry: 77 patients exposed, 

888-362-2500

If you still have concerns and were a dental patient at one of the above facilities during the specified time frame, please call the corresponding facility for additional instructions. TB is a treatable bacterial disease that can be serious and is spread through the air from one person to another.