The CDC and Frontier Airlines have widened their search for people possibly exposed to Ebola by sickened nurse Amber Vinson - including more than 800 passengers who unwittingly flew on a Frontier plane after Vinson.

16 people in Akron and Cleveland, Ohio, who had contact with Ms Vinson last weekend are being monitored by health officials there, local health officials revealed today - up from seven on Thursday.

One, Ms Vinson's step-father, is in strict quarantine.

The CDC announced on Thursday that Ms Vinson may have been contagious as early as last Friday, though she was not admitted to the hospital until Tuesday.

Passengers aboard two flights that Ms Vinson took have been told to monitor themselves for signs of the deadly virus for 21 days over fears that Ms Vinson was contagious both when she flew from Dallas to Cleveland on October 10 and when she returned to Texas on Monday.

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Amber Vinson, 29, is feared to have been exhibiting Ebola symptoms as early as Friday before she took her flight out of Dallas-Fort Worth Airport to Cleveland, Ohio

The Frontier Airlines plane that Amber Vinson flew from Cleveland to Dallas on Monday, flies out of Cleveland Hopkins International Airport on Wednesday. It emerged today that Miss Vinson may have been showing symptoms on her inbound flight to Cleveland

Police have taped off a home in Tallmadge, Ohio which belongs to the mother of Ebola patient Amber Vinson

The plane that Ms Vinson was in made five flights loaded with passengers before the CDC notified Frontier that she may have been contagious.

The airline is now trying to contact its passengers who flew on plane number N220FR, an Airbus A320, before it was removed from service. The plane made flights to Atlanta and Fort Lauderdale, Florida, and back to Cleveland.

WKYC-TV reports that more than 800 passengers are affected by the notice.

Passengers who were on the October 10 Frontier Flight 1142 from Dallas/Fort Worth to Cleveland and passengers on Monday's Flight 1143 from Cleveland to Dallas/Fort Worth have been asked to call the CDC and monitor themselves for symptoms.

The passengers on the other flight are not thought to be at risk for the disease, but Frontier is notifying them anyway. Those flights are:

Flight 2042 on Tuesday morning from Dallas to Cleveland

Flight 1104 on Tuesday afternoon from Cleveland to Fort Lauderdale

Flight 1105 on Tuesday afternoon from Fort Lauderdale to Cleveland

Flight 1101 on Tuesday night from Cleveland to Atlanta

Flight 1100 on Tuesday night from Atlanta to Cleveland

Coming Attractions bridal store in Cleveland Ohio. The store has voluntarily shut after Miss Vinson went to the store with five of her friends

A view of some of the offerings inside Coming Attractions, where Miss Vinson went bridesmaid shopping this weekend

Despite the widening crisis, health officials have stressed that the risk to everyone - the passengers aboard Ms Vinson's plane, the people she came in contact with in Ohio and especially those who flew on her plane on later flights - is minimal.

Officials also stressed that none of the people being monitored have contracted the virus.

CDC Dr Chris Braden revealed during a press briefing on Thursday: 'We had started to look at the possibility that she had symptoms going back as far as Saturday.

'This has to do with the bridal shop. Some more information that has come through recently says we can't rule out that she might have had the start of her symptoms on Friday.'

Seven people in Cleveland and Akron have put themselves in voluntary quarantine after coming into contact with Miss Vinson, including five friends whom she shopped with for bridesmaid dresses at bridal store, Coming Attractions, in Cleveland.

The news has prompted high schools and medical centers in Ohio to send home staff and students amid fears that they could have come into contact with the nurse.

Miss Vinson remained in her home for the three days she was in Cleveland, except for one trip to a bridal store with friends - but authorities are pressing her further on her movements.

The store's owners have voluntarily closed while CDC officials investigate the level of risk.

The owner of the store told Newsnet5 that Miss Vinson didn't seem sick when she visited to pick out dresses.

The 29-year-old is now being treated at Emory in Atlanta, Georgia where she was described as being in a stable condition.

Co-workers help a hazmat worker disrobe on Thursday after coming out of The Village Bend East apartment where a second healthcare worker who has tested positive for the Ebola virus resides in Dallas

A timeline of Ebola patient's Thomas Duncan and the two nurses, Nina Pham and Amber Vinson who contracted the virus while caring for him

Miss Vinson was taken by chartered plane from Dallas to Atlanta Wednesday night, where she is currently being treated at Emory University Hospital

She was airlifted from Dallas, Texas on Wednesday evening on a specialized plane with quarantine unit, along with medical staff in hazmat suits.

Miss Vinson was one of the nurses at Texas Health Presbyterian Hospital to treat Duncan when he was admitted a second time on September 28, in the first 'high-risk' days when there is a high volume of bodily fluids from projectile vomiting, bleeding and explosive diarrhea.

According to CDC guidelines, the nurse should have limited her movements.

It is not clear if Miss Vinson called the CDC before boarding her flight from Dallas to Cleveland.

One and two: Miss Vinson contracted the disease after treating America's Ebola 'patient zero' Thomas Eric Duncan (left). The 29-year-old bride-to-be was the second nurse who treated Duncan to come down with the virus. The first nurse diagnosed was 26-year-old Nina Pham (right) who was in 'good condition' at Texas Presbyterian Hospital on Thursday

Damage control: Texas Health Presbyterian Hospital is currently monitoring more than 75 health care workers who came into contact with Duncan during his stay. On Wednesday, the hospital announced it would be offering free rooms to these staff members, who may not want to risk infecting their family members

Before her return flight on Monday, the nurse noticed a spike in her temperature and called the CDC several times to see if she should get on the plane.

When she finally got through to a CDC representative, she was cleared since her 99.5F fever was beneath the 100.4 threshold.

CDC Director Dr Thomas Frieden admits that was the wrong call.

Dr Frieden also noted that Miss Vinson had flown to Ohio before the first nurse with Ebola, 26-year-old Nina Pham from Fort Worth, was diagnosed with the virus.

Miss Pham was described as being in a 'good condition' today.