The US nurse diagnosed with Ebola after treating an infected man at a Dallas hospital has said she "feels fortunate and blessed to be standing here today", as she is declared free of the virus.

Nina Pham, who was released today from a federal hospital near Washington DC, said she is eager to go home and be reunited with her dog, Bentley, which is still in quarantine.

Her discharge comes as New York authorities seek to quell fears among the city's 8.4 million residents after a doctor in the city tested positive for Ebola.

Ms Pham, 26, arrived last week at the National Institutes of Health Clinical Centre in Bethesda, Maryland.

She thanked a blood transfusion from Dr Kent Brantly, an American doctor who contracted Ebola in Liberia and was cured back in the US.

Ms Pham did not take any experimental drugs for her treatment, officials said.

She was flown to the Maryland facility from Texas Health Presbyterian Hospital Dallas.

She is one of two nurses in Dallas who became infected with Ebola while treating a Liberian man, Thomas Eric Duncan, who died of the virus on 8 October.

Her colleague, Amber Vinson, was declared free of the virus this week, said her family.

In New York City, Dr Craig Spencer was rushed to hospital with fever and gastrointestinal symptoms on Thursday, a week after returning from treating Ebola patients in Guinea with charity Doctors Without Borders.

He tested positive for the disease, which has killed nearly 4,900 people in West Africa, at Manhattan's Bellevue Hospital Centre and has been placed in isolation in intensive care.

Dr Spencer, 33, who reported feeling sluggish from Tuesday, is New York's first case of Ebola and the first in the US outside Texas.