Story highlights 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

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.

JUST WATCHED CDC: Only one patient tested positive Replay More Videos ... MUST WATCH CDC: Only one patient tested positive 01:44

JUST WATCHED 10 people at 'higher risk' for Ebola Replay More Videos ... MUST WATCH 10 people at 'higher risk' for Ebola 01:58

JUST WATCHED Hazmat team cleans quarantined apartment Replay More Videos ... MUST WATCH Hazmat team cleans quarantined apartment 02:18

JUST WATCHED How your hospital handles Ebola Replay More Videos ... MUST WATCH How your hospital handles Ebola 02:02

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.

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.

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.