A healthcare worker at a Texas hospital has tested positive for the Ebola virus.

The worker was employed at the Texas Health Presbyterian Hospital, where Thomas Eric Duncan, the first person in the U.S. to contract the disease, died Wednesday.

According to a statement issued by the Texas Department of State Health Services, the worker reported a low grade fever Friday night and was isolated and referred for testing. The preliminary test result was received late Saturday.

"We knew a second case could be a reality, and we've been preparing for this possibility," said Dr. David Lakey, commissioner of the Texas Department of State Health Services. "We are broadening our team in Dallas and working with extreme diligence to prevent further spread."

The Centers For Disease Control and Prevention will conduct confirmatory testing.

More than 4,000 people have died from the current outbreak of Ebola – a higher death toll than all previous outbreaks combined.

This is a developing story – check back for further updates.