"We can't say this is... unexpected," said New York Gov. Andrew Cuomo (D), at a press conference Thursday night. "The past few weeks we've been preparing for just this circumstance."
Here's everything we know about New York City's first Ebola patient, 33-year-old doctor Craig Spencer.
1. He returned to New York City from Guinea on Oct. 17
Spencer got back to his Harlem apartment on Oct. 17, 10 days after treating patients with the virus in Guinea. He had been closely monitoring his own health - as directed by the Centers for Disease Control and Prevention - by checking his temperature twice a day and being cautious of any other symptoms, such as nausea or vomiting.
2. He began developing symptoms on Thursday.
While Spencer was apparently fatigued on Wednesday, he did not develop symptoms until Thursday. On Thursday morning at 11 AM, Spencer called health authorities with indigestion and a fever of 100.3 degrees. Almost immediately, health responders in full protective gear showed up at his 147th Street apartment to take Spencer to a hospital for treatment.
3. He is in isolation at Bellevue Hospital.
Spencer arrived at Bellevue Hospital at 1 PM on Thursday. He is currently in isolation on the 7th floor.
4. He traveled on public transportation and in an Uber taxi on Wednesday.
Before Spencer called health authorities on Thursday, he spent some time around other people. He rode the A, L, and 1 subway lines, health officials said. On Wednesday evening, he went to The Gutter, a bowling alley in Williamsburg. At the end of the night, he took an Uber back to Manhattan.
Uber said in a statement that neither the driver nor any other passengers were at risk of contracting Ebola. The driver nonetheless isolated himself after finding out that one of his passengers had tested positive for the virus, the New York Post reports.
5. Three of his contacts have been put in isolation.
A Centers for Disease Control and Prevention team immediately went to work tracing Spencer's contacts. His fiancee, whom he lived with, is currently in isolation at Bellevue.
Two of Spencer's other friends, who he spent time with on Tuesday and Wednesday, will also be quarantined, but health authorities have not specified whether they'll be isolated at home or at a health facility. None of the three have shown any symptoms.
6. He was working to help save lives.
Spencer had been treating Ebola patients in Guinea, one of the countries most accutely affected by the current epidemic. On his way to West Africa at a stopover in Belgium, Spencer was photographed in full protective gear.
He posted the photo to Facebook with the caption, "Off to Guinea with Doctors Without Borders (MSF). Please support organizations that are sending support or personnel to West Africa, and help combat one of the worst public health and humanitarian disasters in history."
Before traveling to Guinea to treat Ebola patients, Spencer had worked as an International Emergency Fellow in Rwanda, Burundi, and the Democratic Republic of Congo.
In New York, Spencer works as an attending physician at New York-Presbyterian Hospital in Manhattan.