By Kevin Murphy

(Reuters) - A man in Massachusetts who recently returned from Liberia is being evaluated at a Boston hospital for a potential case of Ebola after complaining of a headache and muscle aches, health officials said on Sunday.

The patient is at Beth Israel Deaconess Medical Center but there is no confirmation of Ebola, said Dr. Kenneth Sands, chief quality officer at Beth Israel.

The response in Massachusetts demonstrates the high state of alert medical facilities are under since a Texas health worker became the first person on Sunday to contract the disease in the United States. She had treated a Liberian man who died of the deadly virus last week.

"We are taking all necessary precautions in collaboration with the city of Boston and the department of public health for the potential that this is suspected Ebola,” Sands said at a news conference. "We are only at the stage where we are doing an assessment."

Sands said if Ebola is suspected, doctors will test him for the disease, possibly with the help of the Centers for Disease Control and Prevention in Atlanta. Testing would take 24 to 48 hours, he said.

There have been several Ebola scares in the United States in the past week. A plane was briefly quarantined at a Las Vegas Airport on Friday after a passenger reported feeling unwell. Health officials around the country have fielded scores of possible cases that were false alarms.

The Massachusetts patient first reported to the Harvard Vanguard Medical Associates hospital in Braintree, Massachusetts, and was then transferred to Beth Israel, said Ben Kruskal, a physician and chief of infectious disease at Vanguard, in a statement.

Kruskal said the Braintree building was closed briefly but reopened

The current Ebola outbreak, the worst on record of the disease, has killed more than 4,000 people, mostly in Liberia, Sierra Leone and Guinea in West Africa.

(Reporting by Kevin Murphy in Kansas City, Peter Cooney in Washington and Frank McGurty in New York; Editing by Lisa Shumaker and Eric Walsh)