AKIPRESS.COM - A Texas health worker has contracted Ebola after treating a Liberian who died of the disease in Dallas last week, raising concern about how U.S. medical guidelines aimed at stopping the spread of the disease were breached, Chicago Tribune said.

Texas Health Presbyterian Hospital in Dallas, where the new case was announced on Sunday, has already faced criticism for its management of the infection.

The infected worker, a woman who was not named, is the first person to contract the disease in the United States. She had close and frequent contact during the 11-day treatment of Thomas Eric Duncan, who died on Wednesday, health officials said.

The current Ebola outbreak is the worst outbreak on record and has killed more than 4,000 people, mostly in West Africa's Liberia, Sierra Leone and Guinea. Duncan, a Liberian, was exposed to Ebola in his home country and developed the disease while visiting the United States.

The new case prompted President Barack Obama to order federal authorities to take additional steps to ensure the American medical system is prepared to follow correct protocols in dealing with Ebola, the White House said on Sunday.

There was no word yet how the health worker was infected, but the director of the Centers for Disease Control and Prevention (CDC) said it indicated a professional lapse that may have caused other health workers at the hospital to be infected as well.

Hospital officials said the worker had been wearing CDC-recommended protective gear during treatment, including gowns, gloves, masks and shields.