The only Ebola patient being treated in the United States has been cleared of the deadly virus.

Health officials say Craig Spencer, a New York City emergency room doctor, is scheduled to be released from the hospital following his recovery.

Mayor Bill de Blasio labelled the 33-year-old a "real hero", saying he had suffered a lot over recent weeks but had "come back really strong".

"I'm sure he's a little weakened from the experience, (but he is) very, very healthy," he said.

Ebola is not airborne and can only be spread through direct contact with the bodily fluids of an infected person who is showing symptoms.

However, news of Mr Spencer's infection left many New Yorkers alarmed, particularly it emerged that he rode the subway, dined in a restaurant and visited a bowling alley in the days before he developed a fever and tested positive.

In response, a mandatory 21-day quarantine for travellers who have come in close contact with Ebola patients was announced.

Mr Spencer tested positive for the virus on 23 October just days after returning from treating patients in Guinea with Doctors Without Borders.