WASHINGTON — The United States will be sending more than 50 disease specialists to West Africa over the next week to help combat the deadliest Ebola outbreak in history, which US health officials estimate will take many months to contain, government witnesses testified Thursday at an emergency congressional hearing.
In coming days, US aid workers will be on the ground assessing the adequacy of treatment centers, ensuring the availability of protective gear for health workers, and working with international partners to improve lab testing of blood samples to more quickly diagnose the disease, said Dr. Tom Frieden, director of the Centers for Disease Control and Prevention.
“We can stop Ebola. We know how to do it. It will be a long and hard fight,” Frieden said at the hearing by the House Foreign Affairs Subcommittee on Africa and Global Health. But the lack of treatment and laboratory facilities makes fighting the outbreak “kind of a fog of war situation.”
The outbreak is unusual because it is spreading in countries that previously had not been exposed to Ebola: Guinea, Liberia, Sierra Leone, and more recently, Nigeria, the continent’s most populous nation. With more than 1,700 infected and 932 dead, it is the largest outbreak ever, with more cases than all previous outbreaks combined.
Representative Chris Smith, a New Jersey Republican, called the rare emergency hearing during the August congressional recess to address international efforts to combat the outbreak, which is centered in three of the world’s most impoverished nations.
The virus — which is not as contagious as influenza or the common cold but much more deadly — is spread through close contact with the bodily fluids of patients already sick with Ebola, not through air, water, food, or casual contact, Frieden said.
The key to stopping its spread is identifying those sick with fever and other symptoms, diagnosing them with a blood test, and isolating and treating them, while tracing people who might have had contact with the ill and monitoring them for 21 days, he said.
“It’s laborious. It’s hard. But that is how Ebola is stopped,” Frieden said.
The more than 50 CDC staff departing for the region will be backed by more than 200 in the agency’s Atlanta headquarters, Frieden said, with the number of CDC staff devoted to combating Ebola increasing substantially in coming weeks.
There is no approved drug for Ebola, but two American health workers who contracted the disease are being treated in Atlanta with an experimental drug, ZMapp, developed by a San Diego company.
“We don’t know whether that medication is harmful, helpful, or will have any impact,” Frieden said. “I don’t want any false hope out there.”
But he said the agency is coordinating with the National Institutes of Health, the Food and Drug Administration, and the Department of Defense to see whether any experimental treatments being developed are effective and can be made available.
On Thursday, the FDA helped clear the way for a second experimental drug to be used to treat people in Africa stricken with the Ebola virus.
The drug, being developed by Tekmira Pharmaceuticals of British Columbia, was in the initial phase of human testing when the FDA halted the trial last month because side effects were observed.
Tekmira announced that the FDA, while still saying the drug, called TKM-Ebola, should not be given to healthy volunteers, was now allowing its use to treat patients actually infected with the virus.
“If there is a new treatment, we will do everything we can to help get it out to those who need it most,” Frieden said.
The health minister of Nigeria told a news conference in his country that he had asked the CDC about access to the drug.
Some people in other affected countries questioned why the experimental medicine being used to treat the American health workers has not been offered to infected Africans.
Anthony Kamara, a 27-year-old riding a bicycle in Freetown, Sierra Leone, said, ‘‘Americans are very selfish. They only care about the lives of themselves and no one else.’’
Asked Wednesday about the drug, President Obama said all the information isn’t in.
‘‘We’ve got to let the science guide us,’’ he said.
Underscoring desperate attempts to stop the disease, troops in full combat gear deployed in the rain to block people from rural areas devastated by Ebola from entering Liberia’s capital. President Ellen Johnson Sirleaf declared a national state of emergency, and officials said Thursday that no one with a fever would be allowed into or out of the country.
The CDC’s Frieden said the spread of Ebola could be prevented through proper infection control, safe burial practices, and reducing the consumption of bush meat or contact with bats.
Traditional burial customs involve venerating the dead by washing the body and kissing the corpse in the hours when the body is most infectious, said Ken Isaacs, vice president of program and government relations at Samaritan’s Purse, one of just two relief agencies that he said have been caring for Ebola victims in West Africa. Relief workers have reported that violence broke out when they tried to sanitize the bodies of victims for proper burial, Isaacs said.