Obama: More Ebola cases possible in the U.S.

President Obama said Wednesday that there may be more cases of Ebola that crop up in the United States as long as the disease is continues to affect people in West Africa.

"Until we stop this outbreak in West Africa, we may continue to see individual cases in America in the weeks and months ahead because that's the nature of today's world. We can't hermetically seal ourselves off," the president said at an event with health care workers who have returned from or are planning to travel to West Africa to fight the disease.

Mr. Obama rebutted his critics' calls for travel bans or aggressive quarantine measures, arguing that neither of those things would stop the disease from affecting more people in the U.S., saying that "the only way to assure that we are safe is to make sure that we have dealt with the disease where right now it is most acute. So yes, we are likely to see a possible case elsewhere outside of these countries and that's true whether or not you adopt a travel ban, whether or not you adopt a quarantine," he said. "It's the nature of diseases. As long as Ebola exists in the world no one can promise there wont be any more cases in America or anyplace else."

The White House has struggled to maintain a sense of control over the U.S. response to Ebola, as states like New York and New Jersey have implemented quarantine measures for returning health care workers that go beyond the recommendations of the Centers for Disease Control and Prevention (CDC). For the second time in as many days, the president said that those workers deserve to be treated as returning heroes because their work to end the spread of Ebola in West Africa will ultimately keep Americans safe as well.

Without mentioning Republicans by name, Mr. Obama rebuked some of his critics for what he sees as hypocrisy on the issue of American leadership.

"When I hear people talking about American leadership and then are promoting policies that would avoid leadership and have us running in the opposite direction and hiding under the covers, it makes me a little frustrated," he said. He closed by saying that those who think America should hide from the threat of Ebola are being "put on notice."

The president was introduced by Kent Brantly, an American doctor who contracted Ebola while working in West Africa and was successfully treated in the United States. Brantly was sharply critical of the American response to Ebola when he testified on Capitol Hill last month, calling U.S. efforts "sluggish and unacceptably out of step with the scope and size of the problem."

In his appearance alongside the president Wednesday, Brantly drew attention to the health care workers traveling to West Africa.

"The world owes them a debt of gratitude," he said.