A SECOND Dallas healthcare worker tested positive for Ebola today — compounding nurses’ union claims that poor standards were putting staff at risk from the disease.

Officials say the unnamed worker was among those caring for Liberian Ebola victim Thomas Eric Duncan, who died in the Texas Health Presbyterian Hospital on October 8.

Nurse Nina Pham, who also helped care for Mr Duncan, was already being treated after contracting the virus, which has killed almost 4,500 people in west Africa.

The second diagnosis came a day after the Nurses United trade union alleged severe lapses in Mr Duncan’s care and in safety procedures for staff at the hospital.

The union released a statement saying that he had been left in an open area of an emergency room for hours and that nurses worked for days without proper protective gear.

Staff were forced to use medical tape to secure openings in their uniforms which left their heads and necks exposed, despite the patient suffering “explosive” diarrhoea and projectile vomiting, both of which spread the illness.

“There was no advance preparedness on what to do, there was no protocol, there was no system,” said Nurses United’s Deborah Burger, citing statements from workers at the as-yet un-unionised hospital.

Lab samples were allowed passage through the hospital’s pneumatic tubes, risking contamination of the specimen delivery system, while hazardous waste was allowed to pile up to the ceiling.

Workers who had treated Mr Duncan were only isolated for a single day before being sent to work with other patients.

Ms Burger did not name the staff who had blown the whistle on the poor practices since they had apparently been warned by the hospital they would be fired if they spoke to the media.

Hospital spokesman Wendell Watson did not respond to the claims but said that staff had not complained to hospital bosses.

But the federal Centre for Disease Control and Prevention said yesterday that the second Ebola case among staff was a “serious concern.”

The World Health Organisation warned yesterday that the death rate among people infected with Ebola has risen to 70 per cent.