Thomas Eric Duncan, the Liberian Ebola victim hospitalized in Dallas, is “fighting for his life,” a top US health official said Sunday.

Dr. Anthony Fauci of the National Institutes of Health told Fox News Sunday that everyone who had contact with Duncan “is being very closely monitored.’’

One of those people, a vagrant described as a “panhandler,’’ had been told to stay where he was, but “he left,” according to Dr. David Lakey, commissioner of Texas’ State Health Services.

The man was later found and placed under “medical surveillance” with about 50 others, who have their temperature checked daily, since fever is a sign of the disease.

Dr. Thomas Frieden, head of the Centers for Disease Control and Prevention, told NBC’s “Meet the Press’’ that US residents have nothing to fear.

“The bottom line is we know how to stop it and it’s not going to spread widely in the US,” Frieden said.

In New York, Sen. Charles Schumer called on the CDC to train airport personnel on how to test travelers arriving directly from Ebola-ravaged countries in West Africa. He raised the possibility of taking their temperatures when they arrive.

He also called for health screenings for crews of cargo vessels arriving in US ports — pointing out that Liberia has the world’s second-largest cargo-ship industry.