A woman is being treated for coronavirus at UC San Diego Medical Center in Hillcrest, a spokesperson for the Centers for Disease Control and Prevention (CDC) confirmed. It is the first confirmed case in the county since the deadly outbreak began.

The patient was among the 232 Americans evacuated from Wuhan, China, last week and flown to Marine Corps Air Station Miramar where they were placed in a 14-day federal quarantine.

A plane carrying 167 U.S. citizens landed at the base Wednesday, and a second plane carrying 65 more landed Friday.

By Sunday, seven people -- all passengers of the first plane -- had at one point been removed from quarantine at the base and placed in isolation at area hospitals for further coronavirus testing.

Four were removed Wednesday when the flight landed, two to UC San Diego Medical Center and a father and daughter to Rady Children's Hospital; a fifth was sent to UC San Diego Medical Center Thursday afternoon; and two were isolated on Friday, one at UC San Diego Medical Center and one at Rady Children's Hospital.

Those passengers had fevers or coughs that warranted further examination, the CDC said.

On Sunday, the CDC said the four patients brought to UC San Diego Medical Center tested negative for the virus and discharged them back to the base, hospital spokesperson Michelle Brubaker said.

Soon after the woman was discharged the CDC notified her that her test results were mislabeled and she, in fact, tested positive for the virus, according to a local health official with knowledge of the case.

She was told to stay in her room at the base while she was retested, and stayed out of contact with others, the official said. She was taken back to the hospital Monday morning.

Another person quarantined at the base was isolated at UC San Diego Medical Center Monday for further evaluation, Brubaker said.

NBC 7's Artie Ojeda has more information on the second plane that landed in MCAS Miramar from Wuhan, China.

Both they and the patient who tested positive are "doing well and have minimal symptoms," she said.

The father and daughter isolated at Rady Children's were released last Friday and returned to MCAS Miramar to continue their quarantine.

In China, more than 1,000 people have died from the virus as of Monday, and more than 440 cases have been confirmed outside mainland China, including two deaths in Hong Kong and the Philippines.

Check back for updates on this developing story.