A second US health care worker has tested positive for Ebola, Texas officials have revealed.

This comes after a nurse at the Texas Health Presbyterian Hospital, where Thomas Duncan - the first person to be diagnosed with Ebola in the US after flying in from Liberia - tested positive for the virus on Sunday.

Nina Pham became the first person to contract Ebola within the United States, and the nurse's infection raised questions about whether American hospitals and their staff are adequately prepared to contain the virus.

Mr Duncan died last week.

The health department said the worker reported a fever on Tuesday and was immediately isolated at Texas Health Presbyterian Hospital.

It said a preliminary Ebola test was conducted at a state public health lab in Austin, Texas, and confirmatory testing will be conducted at the Centres for Disease Control and Prevention in Atlanta.

The statement added that the health care worker, who was not identified, has been interviewed to identify any contacts or potential exposures.