BREAKING NEWS: New York City Doctor Tests Positive for Ebola

A doctor in New York City who recently returned from treating Ebola patients in Guinea has become the first person in the city to test positive for the virus.

The 33-year-old doctor — identified by US media as Craig Spencer — has been placed in isolation, in what is the fourth case of Ebola diagnosed in the United States and the first outside Texas.

The patient had arrived back in America after working with Ebola patients in West Africa for the charity Doctors Without Borders. He arrived at John F. Kennedy International airport on Oct. 17 and went through the ramped-up screening for travelers from the worst-hit West African countries, officials said. But on Thursday, he developed a 103-degree Fahrenheit (39.4 Celsius) fever, nausea, pain and fatigue. He was rushed to New York's Bellevue Hospital, a few hours later, tests confirmed the worst: Spencer has Ebola.

New York City health department detectives are now tracing his movements and officials stressed there was no cause for alarm in the dense city of 8.4 million residents. His fiancée and two friends, with whom he has been in close contact, have been quarantined, New York City health commissioner Mary Bassett told a news conference.