Of the 114 people whom officials first thought could possibly have been exposed to the Liberian man diagnosed with Ebola in Texas, health experts are "fairly certain" that only nine had enough direct contact that they could potentially have been infected.

That's according to an update from CDC director Dr. Tom Frieden, who says that in addition to those nine, about 40 people can't be ruled out as potential contacts. He added that no Ebola-like symptoms have been detected in either group. On Friday, health officials announced they had lowered the number of "contact traces" from 100 to 50.

The group of nine includes some who were in the ambulance that was used to take patient Thomas Eric Duncan to the hospital, Frieden said. Duncan has been in isolation since Sunday, Sept. 28.

Update at 2:25 p.m. ET: Patient Now In Critical Condition

Today's comments from health officials didn't address any specifics about Duncan's condition or the treatment he's receiving. NBC 5 News in Dallas says it has spoken to his nephew, Josephus Weeks, who says the patient "is now on a ventilator."

Duncan has been in isolation for nearly a week at Texas Health Presbyterian Hospital. While his condition had been listed as serious but stable, on Saturday the hospital downgraded his condition to critical.

Our original story continues:

Frieden commended officials in Texas, saying they have organized an effective response to the Dallas case. He spoke around midday Saturday at a news conference based in Atlanta, giving an update on the Ebola case along with Dr. David Lakey, commissioner of the Texas Department of State Health Services, and Dallas County Judge Clay Lewis Jenkins.

Jenkins said that on Friday, he drove four people who had been staying at the Dallas apartment where Duncan had been staying after his arrival from Liberia "to a secure location that was provided by a member from the faith community."

Noting that the group included one woman and three young men, he called them "brave, good people who are concerned about the public health and are obviously concerned about their own health."

Jenkins said that the place in which the group is now staying is one he would be happy to have his own family live.

Frieden, admitting that the first U.S. case of Ebola is "scary and unprecedented," said, "we know how to stop outbreaks of Ebola."

Toward the end of today's update, Jenkins urged people to take the Ebola threat seriously — but not to panic. He noted that he's a married man with an 8-year-old daughter.

"I would not be getting into a car with people being monitored," he said, "if it were not safe to do so."

Here are other recent developments in the Ebola story:

A hazardous-materials crew has decontaminated the apartment where Duncan, the Liberian man diagnosed with Ebola, had stayed with relatives. Bedding and other materials were hauled away after being sealed in industrial barrels.

The relatives are now staying at another private residence, which was offered by a volunteer. They have been ordered to observe a 21-day quarantine to be sure they don't develop Ebola symptoms.

In Liberia, Duncan faces prosecution by officials who say he lied about having had any contact with an Ebola patient (he reportedly helped get a woman to a care center). In Texas, Duncan and his relatives might also face charges.

"We're working with all the different agencies to get to the bottom of it and if it warrants a Dallas County prosecution, then we will pursue it," Dallas County District Attorney Craig Watkins says, according to member station KERA. "But it may be more of a federal issue."

A freelance NBC News cameraman who has been diagnosed with Ebola will leave for Nebraska on Sunday. Officials say Ashoka Mukpo will be treated at the same center that treated missionary Dr. Rick Sacra. His family says Mukpo took precautions after he suspected he was ill."

Diana Mukpo says her son quarantined himself as soon as a fever set in," reports Catherine Welch of Rhode Island Public Radio. "He went to see Doctors Without Borders, and by Thursday, the Ebola diagnosis had been confirmed."

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