A Liberian Ebola patient was left in an open area of a Dallas emergency room for hours, and the nurses treating him worked for days without proper protective gear and faced constantly changing protocols, according to a statement released late Tuesday by the largest U.S. nurses' union.

Nurses were forced to use medical tape to secure openings in their flimsy garments, worried that their necks and heads were exposed as they cared for a patient with explosive diarrhea and projectile vomiting, said Deborah Burger of National Nurses United.

Burger convened a conference call with reporters to relay what she said were concerns of nurses at Texas Health Presbyterian Hospital, where Thomas Eric Duncan — the first person to be diagnosed with Ebola in the U.S. — died last week.

Duncan died Oct. 8, and the hospital said Sunday that one of his nurses had tested positive for Ebola. She is hospitalized and was listed Tuesday in good condition. On Wednesday, Texas health officials announced that a preliminary test indicated a second, unidentified health care worker at the hospital had been infected with the disease.

Texas Health Presbyterian Hospital in Dallas, Tuesday, Sept. 30, 2014. Image: LM Otero/Associated Press

RoseAnn DeMoro, executive director of Nurses United, said the statement came from "several" and "a few" nurses, but she refused repeated inquiries to state how many. She said the organization had vetted the claims, and that the nurses cited were in a position to know what had occurred at the hospital. She refused to elaborate.

Among the nurses' allegations was that the Ebola patient's lab samples were allowed to travel through the hospital's pneumatic tubes, opening the possibility of contaminating the specimen delivery system. The nurses also alleged that hazardous waste was allowed to pile up to the ceiling.

Wendell Watson, a Presbyterian spokesman, did not respond to specific claims by the nurses but said the hospital has not received similar complaints.

"Patient and employee safety is our greatest priority and we take compliance very seriously," he said in a statement. "We have numerous measures in place to provide a safe working environment, including mandatory annual training and a 24/7 hotline and other mechanisms that allow for anonymous reporting."

He said the hospital would "review and respond to any concerns raised by our nurses and all employees."

The nurses alleged that:

Duncan was kept in a non-isolated area of the emergency department for several hours, potentially exposing up to seven other patients to Ebola.

Patients who may have been exposed to Duncan were kept in isolation only for a day before being moved to areas where there were other patients.

Nurses treating Duncan were also caring for other patients in the hospital.

Preparation for Ebola at the hospital amounted to little more than an optional seminar for staff.

In the face of constantly shifting guidelines, nurses were allowed to follow whichever ones they chose.

"There was no advance preparedness on what to do with the patient, there was no protocol, there was no system," Burger said.

Even today, Burger said, some hospital staff at the Dallas hospital do not have proper equipment to handle the outbreak.

"Hospital managers have assured nurses that proper equipment has been ordered but it has not arrived yet," she said.

The nurses' statement said they had to "interact with Mr. Duncan with whatever protective equipment was available," even as he produced "a lot of contagious fluids." Duncan's medical records, which his family shared with The Associated Press, underscore some of those concerns.

Almost 12 hours after he arrived in the emergency room by ambulance, his hospital chart says Duncan "continues to have explosive diarrhea, abdominal pain, nausea and projectile vomiting." He was feverish and in pain.

When Ebola was suspected but unconfirmed, a doctor wrote "using the disposable shoe covers should also be considered." At that point, by all protocols, those shoe covers should have been mandatory to prevent anyone from tracking contagious body fluids around the hospital.

A few days later, however, entries in the hospital charts suggest that protection was improving.

"RN entered room in Tyvek suits, triple gloves, triple boots, and respirator cap in place," wrote a nurse.

The Presbyterian nurses are not represented by Nurses United or any other union. DeMoro and Burger said the nurses claimed they had been warned by the hospital not to speak to the media or they would be fired. They did not specify whether the nurses making the claims were among Duncan's caregivers.

The AP has attempted since last week to contact dozens of individuals involved in Duncan's care. Those who responded to reporters' inquiries have so far been unwilling to speak.

David R. Wright, deputy regional administrator for the U.S. Centers for Medicare & Medicaid Services, which monitors patient safety and has the authority to withhold federal funding, said his agency is going to want to get all of the information the nurses provided.

"We can't talk about whether we're going to investigate or not, but we'd be interested in hearing that information," he said.

CDC officials did not immediately respond to requests for comment.

Duncan first sought care at the hospital's ER late on Sept. 25 and was sent home the next morning. He was rushed by ambulance back to the hospital on Sept. 28. Unlike his first visit, mention of his recent arrival from Liberia immediately roused suspicion of an Ebola risk, records show.

The CDC said Tuesday 76 people at the hospital could have been exposed to Duncan after his second ER visit. Another 48 people are being monitored for possible exposure before he was hospitalized.