The director of the federal Centers for Disease Control and Prevention in Atlanta said Sunday that the agency "is deeply concerned" to learn that "a breach in protocol" at a Dallas hospital resulted in a health-care worker becoming infected with the Ebola virus.
"At some point, there was a breach in protocol," Dr. Tom Frieden said. "And that breach in protocol resulted in this infection."
The CDC confirmed the diagnosis on Sunday afternoon, marking the first known case of the disease being contracted or transmitted in the United States. Ebola has killed more than 4,000 people in West Africa.
Duncan, 42, from Liberia, died Wednesday morning at Texas Health Presbyterian.
Frieden said it appears that the worker had contact with only one person while she might have been infectious. He said the agency will conduct "a complete investigation on how this may have occurred."
Dallas County officials hurried early Sunday to reassure residents that they were not in danger.
"While this was obviously bad news, it is not news that should bring about panic," Dallas County Judge Clay Jenkins said at a somber Sunday morning news conference at the hospital.
"That health-care worker is a heroic person," Jenkins added. "Let’s remember that as we do our work that this is a real person who is going through a great ordeal, and so is that person’s family."
Ebola is not airborne — it is spread through direct contact with bodily fluids of a sick person or exposure to contaminated objects such as needles. People are not contagious before symptoms such as fever develop.
The worker, whose identity was not released, was isolated after reporting a low-grade fever Friday night, the health department statement said. She was "self-monitoring," according to hospital guidelines, and was put in isolation within 90 minutes of reporting symptons, officials said.
The test results were received around 9:30 p.m. Saturday.
An apartment in the 5700 block of Marquita Avenue, near Greenville Avenue, in Dallas was decontaminated, according to Dallas Mayor Mike Rawlings. Rawlings said that neighbors had been notified.
All emergency cases are being diverted from Presbyterian’s emergency room "because of limitations in staffed capacity," the hospital said.
Dr. Daniel Varga, of Texas Health Resources, said the worker was in full protective gear when he or she provided care to Duncan during his second visit to the Dallas hospital. The worker was listed in stable condition Sunday morning.
Varga did not identify the worker and said her family has "requested total privacy."
"We knew a second case could be a reality, and we’ve been preparing for this possibility," said Dr. David Lakey, commissioner of the Texas Department of State Health Services. "We are broadening our team in Dallas and working with extreme diligence to prevent further spread."
Frieden said the CDC is taking several steps to safeguard health-care workers. Among them: Education and training is being ramped up and the agency suggests that the number of workers who care for patients is kept at "an absolute minimum" and that care be limited solely to essential procedures.