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A female nurse who cared for the Liberian patient who died from Ebola in Dallas has tested positive for the virus, marking the first-ever transmission of the disease in the United States.
The nurse, who treated Ebola patient Thomas Eric Duncan at Texas Health Presbyterian Hospital, had reported a fever on Friday and was isolated and tested on Saturday. Tests from a state lab in Texas and the CDC both found her to be positive for the Ebola virus. (To learn more about this Ebola epidemic, read our cardstack.)
"We're deeply concerned by the news," CDC director Tom Frieden said in a Sunday briefing. "We don't know what occurred in the care of the index patient [Duncan] in Dallas but at some point there was a breach in protocol and that breach in protocol resulted in this infection."
The nurse had been wearing personal protective gear — gloves, gown, and a mask — while treating the Ebola patient. She had cared for Duncan on multiple occasions after his diagnosis.
When she went into isolation, her fever was low-grade, which means her infection was at an early stage and she would not have been very infectious. Ebola contagion increases as symptoms worsen and the virus builds up in the body.
Texas Health Presbyterian. (Photo courtesy of Mike Stone/Getty Images News)
"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.
Duncan, the first person to be diagnosed with Ebola in the United States, died at at Texas Health Presbyterian Hospital in Dallas on October 8. He tested positive for the virus over a week after arriving in Dallas from Liberia, one of countries hardest hit by the epidemic.
A hospital misstep in failing to diagnose Duncan at an early stage might have affected his outcome, but it has also affected the lives of everyone with whom he came into contact.
Officials are still following up with 48 people who had some kind of exposure to Duncan or his family prior to Duncan's diagnosis.
The infected health worker was not one of the 48 contacts being traced. The CDC says it is now monitoring all of the contacts who had exposure to Duncan after his diagnosis on September 28, during his hospital stay.
This case of transmission to the nurse will mean that officials now need to find and follow-up with all of her contacts, too. Frieden said the CDC knows of one other individual who definitely had contact with the nurse while she was infectious.
The CDC still says it can contain any US outbreak
"It is certainly possible that someone who had contact with [Duncan]... could develop Ebola in the coming weeks," the CDC director Tom Frieden said previously. Still, he added: "I have no doubt we will stop this in its tracks in the US. I also have no doubt as long as this continues in Africa, we need to be on guard."
That said, the failure to screen and diagnose Duncan on his first visit to hospital — and news that he transmitted Ebola to this nurse — will raise public concern about Ebola, in particular, among health-care workers and hospital staff who might come into contact with Ebola patients in the US.
Frieden said his agency will be looking at how to minimize the risk of transmission to health workers, figure out how to improve the use of personal protective equipment, and boost hospital preparedness for Ebola across the US.
This is part of a wider effort to protect Americans from Ebola. As a precautionary measure, the Department of Homeland Security announced last week that they would begin screening flight passengers coming in from West Africa for signs of infection, starting with five American airports.
For now, though, the major concern is stopping the outbreak at it's source. Ebola is currently concentrated in West Africa, in Liberia, Guinea and Sierra Leone. There, more than 8,000 people have gotten the virus, and more than 4,000 have died.
Transmission from patients to health workers has been an all-too-common feature of this outbreak. More than 230 health workers have died while caring for the sick in this epidemic — an unprecedented number, according to the World Health Organization.
Further reading: How you can and can't get Ebola, The nightmare Ebola scenario keeping scientists up at night, The lesson that should be learned from this Ebola outbreak.
WATCH: How the 2014 Ebola outbreak spiraled completely out of control
