Updated at 11:45 a.m. ET.

A Texas nurse who contracted Ebola while treating Thomas Eric Duncan in a Dallas hospital is now free of the potentially deadly virus, her family says.

Amber Vinson, 29, remains in treatment at Emory University Hospital in Atlanta, but her family said in a statement that since Tuesday evening, doctors had been unable to detect traces of the disease in her blood.

"We all know that further treatment will be necessary as Amber continues to regain strength, but these latest developments have truly answered prayers and bring our family one step closer to reuniting with her at home," Vinson's mother, Debra Berry, said in a statement.

Vinson traveled to the Akron area Oct. 10-13 to prepare for a wedding and was diagnosed on her return to Dallas. Health officials are monitoring 164 people in Ohio who may have had contact with Vinson for signs of the disease, which has a 21-day incubation period.

Fellow nurse Nina Pham, 26, who along with Vinson contracted Ebola treating Duncan at Texas Health Presbyterian hospital in Dallas, was upgraded to "good" condition earlier this week. She is being treated at a facility at the National Institutes of Health in Maryland.

Pham's dog, a cavalier King Charles spaniel named Bentley, has also tested negative for the virus but is still under quarantine, health officials said.

Ashoka Mukpo, a freelance photojournalist who contracted Ebola while working for NBC News in West Africa and was subsequently flown to Nebraska for treatment, has also tested virus-free, hospital officials said Tuesday.

Shortly after an announcement by the Centers for Disease Control and Prevention of new measures requiring a three-week monitoring periodfor anyone arriving in the United States from Ebola-affected Liberia, Sierra Leone or Guinea, President Obama said Wednesday that he's "cautiously optimistic" about the ability of his Ebola response team to contain the disease inside the U.S.

An NPR-Truven Health Analytics poll conducted this month suggests that about half of Americans think the U.S. health care system is prepared to handle an Ebola epidemic on U.S. soil.

The Shots blog reports:

"A clear majority of Americans are worried about Ebola. Fifty-six percent of people are either 'very concerned' or 'somewhat concerned' about the spread of the Ebola virus to this country. ..."People were split pretty evenly on whether the U.S. response has been adequate: 49 percent said yes; 51 percent said no."About three-quarters of people aware of the Ebola outbreak say the U.S. should take steps such as banning travel to and from the affected part of Africa."

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