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- NEW: Ebola patient Thomas Eric Duncan in critical condition
- CDC chief says nine who had definite contact with Duncan showing no symptoms
- Health officials say the other 40 are considered "low risk"
- Monitoring includes a visit from a health official, and temperatures checks twice a day
Dallas (CNN) -- Thomas Eric Duncan, the first Ebola patient diagnosed in the United States, is now in critical condition, a Texas Health Presbyterian Hospital spokeswoman said Saturday.
The Liberian man had previously been listed as being in serious condition. Hospital spokeswoman Candace White offered no new details other than his condition.
Earlier, the U.S. Centers for Disease Control and Prevention said Duncan was in intensive care.
About 10 people are at "higher risk" of catching Ebola after coming into contact with Duncan but have shown no symptoms, health officials said Saturday.
The group is among 50 people being monitored daily, but the other 40 are considered "low risk," said Dr. David Lakey, the commissioner of Texas department of state health services.
The nine people who had definite contact with the Ebola patient -- including family members and health care professionals -- have been monitored and show no symptoms or fevers, Dr. Tom Frieden, director of the Centers for Disease Control and Prevention, said Saturday.
"We have already gotten well over 100 inquiries of possible patients," Frieden told reporters. "We've assessed every one of those ... and just this one patient has tested positive ... We expect that we will see more rumors or concerns or possibilities of cases, until there is a positive laboratory test, that is what they are."
Health officials did not provide details on the location of those being monitored or where they interacted with Duncan.
Monitoring includes a visit from a public health expert and temperature checks twice a day. None of them has had symptoms of Ebola so far, according to Lakey.
The latest figure is a drastic reduction of a number that started at 100 after initial talks with Duncan and hospital officials.
Duncan landed in Dallas on September 20, and started feeling sick days later. He made his initial visit to Texas Health Presbyterian Hospital on September 25.
He was released with antibiotics but went back three days later and was quickly isolated. A blood test Tuesday confirmed he had Ebola, the first case of the deadly virus diagnosed on American soil.
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Relocated to undisclosed location
"We've been very busy the last 24 hours trying to make sure that everyone who has had potential exposure is identified and they have been evaluated," Lakey said.
The high-risk list likely includes Duncan's partner, Louise, her 13-year-old son and her two 20-something nephews. The four had been holed up in the apartment Duncan lived in before he was hospitalized.
They were relocated to an undisclosed place Friday, and will be required to stay there until October 19. The incubation period -- time between Ebola infection and the onset of symptoms -- ranges between two to 21 days.
The Dallas hospital where Duncan is being treated has come under fire for its handling of his first visit there eight days ago.
Louise, who does not want her last name used, said Duncan told hospital staff he had a fever and abdominal pain, and had recently arrived from Liberia -- key information that could have been a tipoff for Ebola.
Health care workers around the nation "have to learn from the experience," Lakey said Saturday.
"The travel history is very important to take and it has to be communicated," he said.
The hospital defended its handling of the case.
"As a standard part of the nursing process, the patient's travel history was documented and available to the full care team in the electronic health record, including within the physician's workflow," it said in a statement.
Your Ebola questions answered
Plans to get married
The church Louise attends said Duncan came to the United States so the two could get married.
Louise told the church's senior pastor, George Mason, about their marriage plan, according to Mark Wingfield, a spokesman at the Wilshire Baptist Church in Dallas.
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Other Ebola scares
As nervous Dallas residents watch Duncan's case unfold, more Ebola scares popped up in other parts of the nation.
Howard University Hospital in Washington said Friday it had admitted a low-risk patient with symptoms that could be associated with Ebola, but health officials on Saturday said Ebola had been ruled out in that case. The unnamed patient had recently traveled to Nigeria.
In Liberia, NBC News freelance cameraman Ashoka Mukpo was diagnosed with Ebola on Thursday, and is expected to leave Monrovia for the United States on Sunday aboard a private charter plane.
In addition to Guinea and Sierra Leone, Liberia is one of three nations battling the deadly virus that has killed more than 3,000 people in West Africa.
2014年10月4日 - 更新2108 GMT（0508 HKT）
九人誰曾與埃博拉患者一定接觸 - 包括家庭成員和衛生保健專業人士 - 已監測，並沒有出現任何症狀或發燒，湯姆·弗里登博士在美國疾病控制與預防主任說，星期六。
疾控中心：只有一個病人呈陽性 10人'高風險'埃博拉 流動宣傳隊清理隔離公寓 你如何處理醫院埃博拉
他們被轉移到一個秘密的地方至五，將被要求呆在那裡，直到10月19日的潛伏期 - 埃博拉病毒感染和症狀出現的時間 - 2至21日之間。
路易絲，誰不希望自己的姓時，鄧肯說，告訴醫院工作人員他有發燒，腹痛，以及最近從利比里亞到了 - 這本來是跳著出場的埃博拉病毒的關鍵信息。