Washington: The first Ebola patient diagnosed in the US died Wednesday at a hospital in Dallas, a city in the northern part of the US state of Texas, hospital authorities said.

“It is with profound sadness and heartfelt disappointment that we must inform you of the death of Thomas Eric Duncan this morning at 7.51 a.m,” Xinhua quoted Texas Health Presbyterian Hospital in Dallas as saying in a statement.

A day earlier, the hospital had listed him in “critical but stable” condition. And the patient reportedly showed some “positive signs. ” Wednesday’s statement did not elaborate on Duncan’s condition.

Duncan, a Liberian national, was tested positive for Ebola Sep 30 as the first confirmed case diagnosed in the US. He arrived in Dallas Sep 20 to visit family and fell ill several days later.

The 42-year-old went to the Dallas hospital Sep 26, only to be dismissed with some antibiotics. Two days later, he was rushed back to the hospital in an ambulance because of a deterioration of illness and had been kept in isolation since.

Health officials in Dallas are now keeping a close eye on some 50 people who may have had contact with Duncan. Among them, 10 people who had close contact with him are deemed to be at higher risk. So far, no one has shown any Ebola symptoms.

Ebola symptoms can include fever, muscle pain, vomiting and bleeding, and can appear as long as 21 days after exposure to the virus.

Ebola, discovered in 1976, has killed 3,431 people and infected 7,470 people since the outbreak in West Africa in March this year, the World Health Organisation said in its latest report.