WASHINGTON (CBS News) -- The current Ebola crisis in West Africa is on pace to sicken more people than all other previous outbreaks of the disease combined, a U.S. health official said Thursday.
Dr. Tom Frieden, director of the Centers for Disease Control and Prevention told a congressional hearing that the outbreak is unprecedented in part because it's in a region of Africa that never has dealt with Ebola before. He said the outbreak's two main drivers are lax infection control during patient care and risky burial practices. It is a custom among some of the countries' populations to kiss corpses shortly after death, at the point when doctors say the bodies are most infectious.
The outbreak can be stopped with tried-and-true public health measures, Frieden said, but it will be laborious. Any case missed or exposed person lost to follow-up could keep the outbreak going.
"If you leave behind even a single burning ember, it's like a forest fire," he said. "It flares back up."
More than 1,700 people have been sickened in the current outbreak, which began in March. Nearly 1,000 have died, according to the World Health Organization. And epidemiologists at one of the organizations that has worked in West Africa to deal with the illness, Samaritan's Purse, estimate that those numbers are just 25 to 55 percent of what is actually happening.
On Thursday Frieden said there's no way to know exactly how accurate that count is, or if some cases are going unreported.
"The data coming out is kind of a fog-of-war situation," he said.
The U.S. Agency for International Development is spending $14.5 million to combat the Ebola outbreak and has sent a disaster response team to the area to assist workers, said assistant administrator Dr. Ariel Pablos-Mendez. The work includes sending tens of thousands of protective suits for health care workers.
In addition, CDC is working to open more treatment centers and expand proper Ebola testing, Frieden said. Pablos-Mendez said that equipment is already being sent and training has been prepared in Ghana, predicted to be the next country hit with the disease.
Frieden didn't rule out the possibility that a traveler could arrive in the U.S. infected with Ebola. But he said he is confident there will not be a large Ebola outbreak here. The CDC has put hospitals on alert for symptoms, and to check whether people are recent travelers so that they can promptly isolate any suspected cases until proper testing can be done.
But Ken Isaacs, the vice president of Programs and Government Relations at the relief organization Samaritan's Purse, told members of the committee that the disease has the potential to threaten the national security of many nations, including the United States, and that "the cat is most likely out of the bag."
"It is clear to say that the disease is uncontained and out of control in west Africa," Isaacs said, then adding, "The international response to the disease has been a failure."
Isaacs, who saw the crisis coming in April, said the ministries of health in the affected countries "simply do not have the capacity" to handle the virus. He also said high rates of illiteracy in those nations makes campaigns to stop the spread of Ebola through burial practices difficult, saying, "Putting a poster on the wall that says, 'Ebola kills' is not gonna do it."
Two relief agencies, Samaritan's Purse and Doctors Without Borders, have been tasked over the past several months with providing "all of the care" for the victims, Isaacs said. Isaacs expects a spike in the disease in Nigeria, following by a three-week quiet and then a huge return of the disease.
"When it comes out, it will come out in a fury," he said.
Dr. Frank Glover, the president of a health organization that works in Liberia called SHIELD, said if nothing more is done, deaths in Liberia could reach into the thousands.