美疾控中心证实第二例埃博拉

 HOUSTON, Oct. 12 (Xinhua) -- A confirmatory test done by the U. S. Centers for Disease Control and Prevention (CDC) late Sunday proved a health care worker at a Dallas hospital, who cared for the deceased Ebola patient Thomas Eric Duncan, is positive for the virus.

Earlier in the morning, Texas health department issued a statement, saying that the worker tested positive for Ebola in a preliminary test and that a second test was needed to confirm the diagnosis 1. The CDC finished the test and announced the result on Sunday afternoon.
"Today, the Centers for Disease Control and Prevention confirmed test results reported late last night by the Texas Department of State Health Services' public health laboratory showing that a health care worker at Texas Presbyterian Hospital is positive for Ebola," the agency said.
U.S. CDC confirms 2nd case of Ebola in DallasThe case marked the first person-to-person transmission of Ebola on U.S. soil and the second person diagnosed in the country.
The worker, reportedly a female nurse, is believed to have contracted the virus as a result of a "breach 2 of protocol 3," officials said. Authorities did not name the exact kind of breach, but epidemiologists speculate it could happen during kidney dialysis,respiratory intubation and removal of contaminated gears.
The nurse was in full protective gear when providing care to Duncan, the Liberian visitor who was diagnosed to be the first U.S. Ebola patient on Sept. 30 and died Wednesday.
Dr. Thomas Frieden, director of the CDC, said in a press conference that the nurse's colleagues who also cared for Duncan could become infected as well because they might have the same kind of breach in protocol. Until the source of the caregiver's exposure is determined 4, Frieden said, the CDC is recommending that the number of health care workers who treat potential Ebola patients be kept to a minimum.
The caregiver is among 19 medical staff at the Dallas hospital who had close contact with Duncan after he was hospitalized on Sept. 28. They are asked to do self-monitoring and report to authorities once they find any signs of the disease.
Meanwhile, authorities are tracking those who had contact with the nurse after she began showing symptoms. It's believed that there is only one person who certainly had close contact with her and that person has already been quarantined.
Health officials are also keeping close watch on 48 people who may have had contact with the deceased patient Duncan. None of them so far have shown any signs of the disease. Their observation will be lifted on Oct. 19 when the incubation period of the illness is supposed to end.
Ebola is spread through direct contact with bodily fluids of an infected symptomatic person or through exposure to objects that have been contaminated with infected secretions 5. The virus can incubate as long as 21 days.
Duncan, 42, arrived in Dallas on Sept. 20 and fell ill several days later. He had already been showing symptoms during his first visit to Texas Health Presbyterian Hospital on Sept. 25. But the hospital did not weigh his case until his second visit on Sept. 28.
Officials said the new patient was infected during Duncan's second visit to the hospital. Duncan was kept in isolation 6 from Sept. 28 to Oct. 8, during which time the nurse had "extensive contact" on "multiple occasions" with him, according to officials.
The nurse reported a low grade fever and was referred for testing Friday. She reportedly drove to the hospital. The preliminary test suggested the level of the Ebola virus in her was "low". She is in stable condition as of Sunday evening.