A health care worker who treated the man who died of Ebola last week has tested positive for the deadly virus, according to Texas health officials.

The Dallas Morning News reports, "The health worker who has contracted Ebola was not in the group of people public health workers had identified as being at high risk of exposure to Thomas Eric Duncan, the first person to die of Ebola in the United States."

According to the NY Times, "The health care worker reported a low grade fever Friday night and was isolated and referred for testing... The preliminary test was done at the state public-health lab in Austin and the positive result was received late Saturday, officials said. Other tests will be done by the federal Centers for Disease Control and Prevention in Atlanta."

Texas Health Commissioner Dr. David Lakey said, "We knew a second case could be a reality, and we've been preparing for this possibility."

Neighbors of the health care worker were informed they were living near someone with Ebola and, per the Dallas Morning News, "The person's car was decontaminated and the common area of an apartment complex in the 3700 block of Marquita was cleaned by a hazardous-material team. The team will be cleaning the interior of the apartment Sunday. There is a pet in the apartment."

Duncan, a Liberian national, succumbed to the virus last Wednesday, 10 days after he was admitted to the hospital. Duncan was the first person to be diagnosed with Ebola in the United States. Doctors didn't initially suspect Ebola when he first went to the hospital because the fact that he was Liberia was never communicated them—his friend claims that she told the hospital this twice—and he was sent home.

Later, clean-up workers balked at sanitizing the apartment that Duncan was living in before entering the hospital.

The CDC has more information about Ebola, including how it's transmitted: "Ebola is not spread through the air or by water, or in general, by food" but it is spread through direct contact, "through broken skin or mucous membranes in, for example, the eyes, nose, or mouth."