New York City has reported its first case of Ebola. Dr. Craig Spencer tested positive after returning last week from Guinea where he was treating Ebola patients with Doctors Without Borders. New York City Mayor Bill de Blasio said Spencer is in isolation at Bellevue Hospital in Manhattan.

Bill de Blasio: “The patient in question is a doctor who has worked with Ebola patients in West Africa, and when his symptoms emerged, he was taken to Bellevue by specially trained emergency medical service workers who followed all transport protocols. The patient is now in isolation. The Health Department has a team of disease detectives who have been at work tracing all of the patient’s contacts, and we are prepared to quarantine contacts as necessary.”

The West African country of Mali also reported its first case of Ebola on Thursday. The patient is a two-year-old girl who was brought from neighboring Guinea. Her father died of Ebola.