Doctor in New York City Diagnosed With Ebola

A doctor who treated Ebola victims in Guinea has been diagnosed with the virus in New York, in the first U.S. case confirmed outside of Dallas.

Dr. Craig Spencer was rushed to Bellevue Hospital Center in Manhattan on Thursday after he called authorities and reported a fever and gastrointestinal symptoms. An initial blood test came back positive for Ebola.

Spencer is the fourth person in the U.S. to be diagnosed with Ebola. The first case, Thomas Eric Duncan, died in Dallas earlier this month, and two nurses who treated him have become infected. One of those nurses, Amber Vinson, was cleared of the virus on Wednesday. Spencer's diagnosis is likely to cause concern in New York because he traveled on the subway and went to a bowling alley in Brooklyn on the night before he came down with a fever. Spencer, 33, worked with Doctors Without Borders in Guinea and returned to the U.S. a week ago, officials said Thursday night.

The CDC has dispatched a rapid response team to New York, and "disease detectives" were trying to reach people who had come in contact with Spencer in recent days. CDC director Dr. Thomas Frieden said that by coincidence, the center already had a team in New York observing Bellevue's preparations for a possible case.

City and state officials immediately sought to head off a public panic at the first case of Ebola in the nation's largest and densest city. "We want to state at the outset that there is no reason for New Yorkers to be alarmed," New York Mayor Bill de Blasio said in a nationally-televised press conference.

The city's health commissioner, Dr. Mary Bassett, said Spencer had felt fatigued in recent days but did not have a fever until Thursday morning. He had been checking his temperature twice a day since returning from west Africa. Three of Spencer's contacts will be monitored for symptoms for 21 days, Bassett said.