President Obama said Thursday his administration must respond in a "much more aggressive way" to the threat, but the president's spokesman said a ban on travel from the Ebola-stricken countries to the U.S. is not on the table. Some Republican lawmakers have sought the ban, but such a measure is not under consideration, White House spokesman Josh Earnest said.

In a hearing on Capitol Hill this afternoon, the chairman of a House committee cited "demonstrated failures" in the government's response. Rep. Tim Murphy of Pennsylvania said the "trust and credibility of the administration and government are waning as the American public loses confidence each day."

Dr. Tom Frieden, director of the CDC, testified that despite the latest incidents, "we remain confident that our public health and health care systems can prevent an Ebola outbreak here."