(CNSNews.com) - "While the media coverage is already decreasing and people maybe feel like that Ebola has peaked, we do not think it has," Ken Isaacs, a vice president of Samaritan's Purse, a told Congress on Tuesday.
Isaacs said while much has been learned about Ebola, the virus is "sneaky," and it continues to surprise the experts. "And I think that we, as a society, cannot make assumptions that we know what it is and what it will do. I think that we need to be extraordinarily careful about letting it come on to this shore."
Isaacs told a House Energy and Commerce subcommittee that travel restrictions -- he called it "travel management" -- should remain under consideration as a way to reduce the threat to the United States.
"The real threat to the United States is what will happen if the disease spreads into countries that cannot handle it," he said. He mentioned India, China, Pakistan, Myanmar, Bangladesh, all of them countries that are highly populated and have low public health and hygiene standards.
"You could see a death toll that would be unimaginable, and the impact around the globe would affect us as well."
Isaacs said the handful of Ebola cases in this country were quickly isolated, but multiple cases -- "10 or 20 or 50" -- would quickly overwhelm U.S. capacity to deal with them.
"So while we can isolate it, if it were to get out from under us, it would quickly exceed our capabilities, and that's why I think it is so extremely important to invest resources to fight and stop this disease in Africa before it gets off that continent in a major way."
Ebola is not the flu, Isaacs said. It kills 70 percent of the people who get it. And while the caseload is going down in Liberia, it is now spreading to Mali and increasing in Sierra Leone.
"So it's clear that the disease has not peaked. Actually, if anything, I would say that it perhaps has run its course and we don't know what its course is. And if you look at the epidemiological charts in Sierra Leone, it has peaked two times before. So, the question really is, are we at a peak or are we in a trough before the next uprise?" he asked.
Isaacs said there are many other "important questions" that experts simply cannot answer about the disease.
-- How are doctors returning to America becoming infected when they were all wearing level-four protective gear?
-- Can the virus live in other mammals besides primates, bats, rodents and humans?
-- Where does the virus live? Can it jump into the animal population here?
-- Is it possible that Ebola can be asymptomatic? (Isaacs said blood drawn from some apparently healthy patients has tested positive for Ebola.)
-- If 95 percent of cases develop within 21 days, does that mean five percent develop in 42 days?
"You know, I will just say, I'm not trying to be a fear monger. But I think that there are things that we need to look at critically, and we should not be afraid to ask questions," Isaacs said.
Ken Isaacs is the vice president of programs and government relations for Samaritan's Purse, an evangelical Christian organization that helps victims of war, poverty, natural disasters, disease, and famine.
At the White House on Tuesday, President Obama said eight of the ten Ebola patients treated in this country have survived.
"America has proven that it can handle the isolated cases that may occur here," the president said. "But as long as the outbreak continues to rage in the three countries in West Africa, Liberia, Sierra Leone, and Guinea, this is still going to be a danger not just for America but for the entire world. We are nowhere near out of the woods yet in West Africa."
Obama said until Ebola is eradicted in Africa, "there are threats of additional outbreaks, and given the nature of international travel, it means that everybody has some measure of risk."
Obama urged Congress to quickly pass his emergency funding request to respond to Ebola, both domestically and internationally.