Some of the healthcare workers being monitored are being furloughed, but others have continued to work, depending on the level of their exposure. None are allowed to use public transit.
Until now, public statements have indicated that the only people potentially exposed were Presbyterian hospital workers, nurses and doctors, not public health officials.
Duncan's hospital chart shows she was, at least once, with the victim.
At 10:45 a.m. on Sept. 30, nurse Nina Pham — who has since tested positive for Ebola — noted an infectious disease specialist "and Dr. Chung at bedside." About three hours later, Pham wrote that results have confirmed Duncan tested "positive for Ebola."
Dr. Barry Rosenthal, chairman of Emergency Medicine at Winthrop-University Hospital in Mineola, New York, said that while he cannot speak to the situation in Dallas, it's neither typical nor advised for an epidemiologist to enter an isolation room and interview a contagious patient. Their role in outbreaks, he said, is to track cases to find out who else might have been exposed, research that can be conducted by phone or video monitor to avoid potential contact.
In addition, Centers for Disease Control and Prevention director Dr. Tom Frieden has said that too many health workers had contact with Duncan, and he announced steps this week to minimize the number of people in the room with Ebola patients.
Chung was not immediately available for further comment.
Dallas County Judge Clay Jenkins, who is responsible for the county's disaster and emergency preparedness, said he and Chung have been working side-by-side throughout the outbreak. Jenkins said their pace has been so intense at a hospital command center that they've set up a room with cots where Chung and others can rest.
He said he has not heard she was being monitored in any way, "and it would be surprising if I wouldn't know that."
Prior to Chung's bedside visit with the Ebola patient, she was actively consulting on his case, according to Duncan's medical records.
A nurse wrote about 12 hours after Duncan arrived at the emergency room that the county's epidemiologist had been consulted. The nurse wrote that after speaking to Chung, the epidemiologist said Duncan "should be quarantined along with all equipments. Minimize lab studies, and testing."
Duncan visited the emergency room 13 days before his death. He was sent home, misdiagnosed with a sinus infection. He returned in an ambulance two days later.