Federal health officials in the US admitted on Sunday they were deeply concerned by a “breach in protocol” after it was revealed that a healthcare worker who treated Thomas Eric Duncan in Dallas had become the second person to be diagnosed with Ebola in the US.

Four days after Duncan died in an isolation unit, after arriving in Dallas last month from Liberia, secondary tests confirmed that a female employee at Texas Health Presbyterian hospital has the virus, in the first case of Ebola transmission in the US and the second outside Africa.

Texas officials earlier said preliminary tests showed the worker had been exposed to Ebola, but they were awaiting confirmation from the Centers for Disease Control and Prevention (CDC). Confirmation followed on Sunday afternoon.

The White House said President Barack Obama had been updated about the case.

Hospital officials said the employee had worn full protective clothing during all contact with Duncan. Dr Tom Frieden, the CDC director, warned in a media briefing on Sunday that other hospital staff could also have been exposed to the virus and may show symptoms in the coming days.

“The healthcare workers who cared for this individual may have had a breach of the same nature,” Frieden said. “It is certainly very concerning and it tells us there is a need to enhance training and make sure protocols are followed.

“The protocols work … but we know that even a single lapse or breach can result in infection.”

The White House said Obama had asked the CDC to move as quickly as possible in investigating the apparent breach of infection control procedures, and told federal authorities to take more steps to make sure hospitals and healthcare providers are ready to follow the proper procedures in dealing with an Ebola patient.

The woman infected by Ebola in Dallas, who was identified in media reports as a nurse, treated Duncan after he fell gravely ill and was admitted to hospital on 28 September, his second visit to the hospital.

Hospital chief clinical officer Dr Daniel Varga said in a statement: “Individuals being monitored are required to take their temperature twice daily. As a result of that procedure, the caregiver notified the hospital of imminent arrival and was immediately admitted to the hospital in isolation.

“The entire process, from the patient’s self-monitoring to the admission into isolation, took less than 90 minutes. The patient’s condition is stable.”

The Texas health commissioner David Lakey said the test that confirmed the woman’s infection was conducted in a laboratory in Austin and came back positive on Saturday evening, but showed lower levels of the virus than in Duncan’s case.

“It’s deeply concerning that this infection occurred,” Frieden said. “We can’t let any hospital let its guard down.”

The woman was not among the 48 people officials are monitoring during the virus’s 21-day incubation period who may have contact with Duncan and are so far asymptomatic. Lakey said health officials were working to identify people who may have had contact with her once she started showing symptoms and as a result became contagious.

Frieden said that so far they had found only one such person, who was “under active monitoring”, but “it is possible that other individuals were exposed”.

He said that the woman had “extensive contact … on multiple occasions” with Duncan following his second visit to the hospital, where he was admitted and isolated.

Teresa Romero, a 44-year-old Spanish nurse, contracted Ebola after caring for a priest who had been repatriated from west Africa. She is being treated in a Madrid hospital and has told El Pais that she believes she may have made a mistake when taking off her protective suit, perhaps touching her face with her gloves.

Frieden said the second patient in Dallas has been interviewed but so far “that worker has not been able to identify a specific breach” which may have resulted in her exposure. The CDC said that on Friday the worker, who had been self-monitoring for Ebola symptoms, reported a low-grade fever and was referred for testing. She was promptly isolated, officials said.

After a series of missteps in Duncan’s case, federal and Texas officials have sought to quell public fears about the threat of the virus and the ability of government agencies to contain it. But news that one of its workers has contracted Ebola despite taking precautions puts the hospital under further pressure.

CDC chief Tom Frieden at a news conference in Atlanta. Photograph: John Amis/AP

On 26 September, Duncan went to the hospital for treatment but was sent away with antibiotics after hospital staff seemingly failed to consider that he might have Ebola despite being made aware of his travel history. Medical records obtained by the Associated Press indicated that Duncan was feverish with a temperature of 103F on that visit. He then fell gravely ill and was rushed to the hospital on 28 September, where he was isolated. His diagnosis was confirmed on 30 September.

He was staying with Louise Troh, his partner, in an apartment less than a mile from the hospital. Relatives of Duncan’s family have indicated in statements to the media that they are unhappy with the hospital’s failure correctly to diagnose the 42-year-old during his first visit and dissatisfied with the standard of treatment he received once the case was confirmed. They are believed to be considering legal action against the hospital.

After being criticised for their sluggish response to Duncan’s diagnosis, which left several quarantined family members stuck in the apartment for several days before they were taken to a home at an undisclosed location and a hazardous-materials cleaning crew arrived to decontaminate the unit, Dallas officials were at pains in a Sunday morning media briefing to stress they have acted more decisively this time to clean and control access to the nurse’s residence.

Mayor Mike Rawlings said a team “has cleaned up the common areas and decontaminated the common areas and decontaminated any of the open areas of an apartment complex … they sprayed with a decontaminant, a clean-up agent and right now police are standing by to make sure no one enters. Furthermore, we have knocked on every door in that block and helped every single person who came to the door, explained what has happened.”

Rawlings also said a pet was believed to be inside the healthworker’s apartment, but was not believed to be exhibiting signs of Ebola and would be taken care of. This week, a dog belonging to the Spanish nurse infected with the disease was destroyed.



Rawlings said that reverse 911 calls had been made to nearby residents to inform them of the diagnosis and that officials would return to knock on doors again on Sunday and talk to any people they had missed. Printed materials were left at every door, Rawlings said.

Media images showed a police officer blocking the entrance to a small apartment building less than four miles northeast of downtown Dallas and four miles south of the hospital where Duncan died. Similar images showed a yellow barrel containing hazardous waste sitting on the front lawn of the building.

Facebook Twitter Pinterest Police confer as a barrel for disposal of hazardous waste sits outside the apartment of the health worker. Photograph: Louis DeLuca/AP

A neighbour, Cliff Lawson, 57, told Reuters he was woken at 6am by two Dallas police officers, who told him “don’t panic”.

“I went back to bed after that. There’s nothing you can do about it. You can’t wrap your house in bubble wrap,” Lawson said.

During a briefing, Varga declined to provide a detailed timeline of events leading to the worker’s hospitalisation, citing patient privacy rights. He said the hospital was tracking 18 of its employees for possible exposure in the wake of Duncan’s admission and that the current patient had not been considered as high risk.

The hospital has a 24-bed intensive care unit which it is using exclusively as an Ebola care unit. Varga said the hospital was not accepting any more emergency patients.

Enhanced screenings of travellers arriving at five major US airports from Liberia, Sierra Leone and Guinea began at New York’s JFK on Saturday. Newark, Washington Dulles, Atlanta and Chicago O’Hare will follow suit on Thursday.

More than 4,000 people in the three west African countries have died from the current Ebola outbreak, according to the CDC.

At the Sunday morning press conference held at the hospital, Dallas County judge Jenkins sought to calm public fears. He said: “I want to stress an important fact. You cannot contract Ebola other than from bodily fluids of a symptomatic Ebola victim. You cannot contract Ebola by walking by people in the street or from contacts who are not symptomatic. There is nothing about this case that changes that basic premise of science.



“And so it’s important that while this is obviously bad news, it is not news that should bring about panic. We have a strategy to monitor this and we will go to that strategy to keep the community safe.”