The CDC says the spread of Ebola in the United States is very unlikely. But that doesn’t mean there’s no danger for some people. Early today, CDC head Tom Frieden noted, "We need to consider the possibility that there could be additional cases, particularly among the health care workers who cared for the index patient when he was so ill. That's when this health care worker became infected, and we're concerned and would unfortunately not be surprised if we did see additional cases in the health care workers who also provided care to the index patient."
The “index patient” is Thomas Duncan, the man who died of Ebola in a Dallas hospital after arriving there from Liberia. Thomas Ksiazek is former chief of the CDC’s Pathogens Branch, which studies infections diseases. He’s now director of high containment laboratory operations at the Galveston National Laboratory. In August and September, he was in Sierra Leone to assist the government in controlling the Ebola outbreak.