An Ebola-infected Texas nurse who traveled to Ohio over the weekend to plan for her wedding may have been ill as early as Friday, a spokesman for the U.S. Centers for Disease Control and Prevention said on Thursday.

Dr. Christopher Braden told a news conference in Ohio that the CDC may include people who were on a flight Amber Joy Vinson, 29, took to Cleveland from Dallas on Friday in its investigation of possible contacts.

Vinson went to a bridal shop in Akron on Saturday but otherwise spent the weekend mainly with family before taking a return flight to Dallas on Monday, the day before she was diagnosed with Ebola, according to county health officials.

"We had started to look at the possibility that she had symptoms going back as far as Saturday," Braden said.

"But some more information that's come through just recently would say that we can't rule out the fact that she might have had the start of her illness on Friday."

Dr. Marguerite Erme, medical director for Summit County, told the news conference that people who visited Coming Attractions Bridal & Formal Inc in Akron from noon to 3:30 p.m. on Saturday should contact health officials.

Eight people who had confirmed contact with Vinson during her Ohio visit in Summit and Cuyahoga counties are in voluntary quarantine and have not shown symptoms of the virus, county health officials said.