A physician with Doctors Without Borders who recently returned from West Africa has tested positive for Ebola, the New York Times reported on Thursday.


The doctor, identified as Craig Spencer, was working for the humanitarian organization in Guinea, one of three West African nations hardest hit by Ebola.


The New York Times said Spencer was placed in isolation at Bellevue Hospital and that a further test would be performed by the U.S. Centers for Disease Control and Prevention to confirm the finding.


The New York City Department of Health and Mental Hygiene said earlier it was tracing all of the patient's contacts to identify anyone who may be at potential risk.


"It is our understanding very few people were in direct contact with him," New York Mayor Bill de Blasio said at a news conference. "Every protocol has been followed."