A physician with Doctors Without Borders who returned from West Africa recently has tested positive for Ebola at a New York City hospital, the city's mayor confirmed.

The doctor developed a fever and gastrointestinal symptoms, the New York City Department of Health and Mental Hygiene said in a statement on Thursday.

The doctor has been identified as Craig Spencer, who lives in Manhattan's Harlem neighbourhood, according to New York City Councilman Mark Levine.

Craig Spencer [LinkedIn]

"A person in New York City, who recently worked with Doctors Without Borders in one of the Ebola-affected countries in West Africa, notified our office this morning to report having developed a fever," Doctors Without Borders said in a statement.

Mayor Bill de Blasio at a news conference early on Friday said "New Yorkers have no reason to be alarmed... Every hospital in the city is prepared in case other patients come forward.""It is our understanding very few people were in direct contact with him... Every protocol has been followed."

"We're hoping for a good outcome for this individual," he said.

New York State Governor Mario Cuomo also said that proper procedures were being followed in treating the patient.

"We have the situation under control," he said. "The more facts you know, the less frightening the situation is."

The doctor reported his fever on Thursday morning, and Doctors Without Borders said it promptly notified the city health department.

The patient, who returned to the United States within the past 21 days, is being treated at Bellevue Hospital, the health department said. Twenty-one days is the maximum incubation period for Ebola.

Bellevue, a historic city hospital, is one of the eight hospitals in New York state designated earlier this month as part of an Ebola preparedness plan.

Spencer's Facebook page showed a photo of him clad in protective gear. It shows he went to Guinea around September 18 and then to Brussels on October 16.

Spencer has been a fellow of international emergency medicine at Columbia University-New York Presbyterian Hospital in New York City since 2011, according to his profile on the LinkedIn career website.

Columbia did not respond to a request for comment.

The health department said it was tracing all of the patient's contacts to identify anyone who may be at potential risk. It said the patient had been transported by a specially trained unit wearing protective gear.

The case is the first infection reported in the US state of New York, and the fourth in the entire US.

Earlier in October, a Liberian man who travelled to the US state of Texas from Liberia, contracted the disease, and later died at a Dallas hospital. Two nurses who helped with the case also tested positive, and are still recuperating at different medical facilities in Georgia and Maryland.

First case in Mali

In West Africa, the state of Mali has reported that one of its citizens contracted the virus, the first case reported in the landlocked country.

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Mali's health ministry in the capital Bamako confirmed the case on Thursday.

A medical source told Al Jazeera that the patient was a two-year old child, who tested positive for the virus after arriving from Guinea with her grandmother.

The same source said the patient came from the city of Kai, about 400km southeast from Bamako.

Mali shares a border with Guinea, and is the only country which has not sealed its border with the Ebola-hit neighbouring country.

As of October 19, there were 1,289 confirmed cases in Guinea, with a total of 904 deaths.

In total, 4,877 people have died of the disease and experts warned that the rate of infections could reach 10,000 a week by early December.

Source: Agencies