A second female health care worker at the Dallas hospital where Ebola patient Thomas Eric Duncan was treated has tested positive for the virus, Texas health officials confirmed Wednesday, as the state prepares for the possibility of more cases.

“We are preparing contingencies for more and that is a very real possibility,” Dallas County Judge Clay Jenkins said during a press conference Wednesday morning.

"It may get worse before it gets better," said Dallas Mayor Mike Rawlings.

Officials did not specify what position the worker held at Texas Health Presbyterian Hospital, but they did say she was among those who provided care for Duncan, who died from the virus Oct. 8.

One of the health care worker's relatives identified her as Amber Vinson, a nurse at Texas Health Presbyterian Hospital.

A check of public records by Reuters showed that Vinson lived at the apartment complex identified as the home of the latest patient. Public records indicate that she is 29 years old. Officials confirmed the second patient lived alone on the 6000th block of Village Bin Drive and without pets.

“Like Nina Pham [a nurse, and the first  health care worker at the hospital to test positive for Ebola], this is a heroic person, a person who is dedicating her life to helping others and is a servant leader,” said Jenkins.

Officials confirmed that within 90 minutes of reporting a fever, the health care worker’s temperature was taken and she was placed in isolation.

Preliminary tests were run at the state public health lab in Austin and results came back at approximately midnight Wednesday. A separate test will be done this morning at the Centers for Disease Control and Prevention (CDC) in Atlanta.

Officials have said the health care worker was interviewed quickly to identify any contacts or potential exposures, and that others will be monitored. The type of monitoring will depend on the nature of their interactions with the health care worker, and the potential of exposure to the virus.

Jenkins said health officials are currently monitoring more than 70 others who treated Duncan. These workers are employed but not working.

“You can imagine the anxiety of the families of these 77 people,” said Jenkins. “You can imagine the gut shot that this is to the family that is Presbyterian hospital has done a great job taking care of this community in many, many years.”

During the press conference, officials did not confirm the number of possible contacts with the worker.

Dallas Mayor Mike Rawlings said the city has sent a team to her apartment to disinfect the patient’s home and the inside of her car, which will be removed this afternoon.

On Sunday, officials confirmed that Pham, 26, had tested positive for the virus. Pham received a blood transfusion from a recovered Ebola patient and has moved from “stable” to “good” condition, Jenkins said. Pham’s dog has also been isolated.

More than 70 people who may have had contact with Duncan at the hospital are currently being monitored. The 48 contacts outside of the hospital who may have had contact with Duncan are asymptomatic, and Sunday marks the end of the 21-day incubation period, during which Ebola symptoms can arise after direct contact.

Officials have not said when or how the second health care worker or Pham may have had contact with Duncan. But the second case pointed to lapses beyond how one individual may have donned and removed personal protective garb.

“There’s clear there was an exposure somewhere, sometime in the treatment of Mr. Duncan,” Dr. Daniel Varga, chief clinical officer for Texas Health Presbyterian, said during the conference. “Let’s be clear, we’re a hospital that may have done some things different with the benefit of what we know today. But make no mistake, no one wants to get this right more than our hospital first to diagnose and treat this insidious disease that’s now attacked two of our own.”

The Ebola virus is transmitted when a person comes in direct contact with an infected, symptomatic Ebola patient’s bodily fluids, such as blood, sweat, saliva and tears.

News of the latest positive test comes one day after the largest U.S. nurses' union charged that Duncan's caregivers worked for days without proper protective gear and faced constantly changing protocols.

A statement from National Nurses United also says Duncan was left in an open area of an emergency room for hours.

A spokesman for the group says nurses were forced to use medical tape to secure openings in their flimsy garments. It's said that the patient had explosive diarrhea and projectile vomiting.

In a conference call with reporters executive director RoseAnn DeMoro says the allegations are based on revelations from "a few" nurses and that the claims were vetted.

The nurses also said that Duncan'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.

A hospital spokesman told the Associated Press that the facility had not received similar complaints.

The Associated Press and Reuters contributed to this report.