Obama aide: We're near pivot point in Ebola fight

President Obama's top adviser on the fight against Ebola says signs are good in the United States, but challenges remain at the source of the virus in West Africa.

Officials are making good progress in Liberia, but there are still problems in Sierra Leone and Guinea, said U.S. Ebola Response Coordinator Ron Klain in a Sunday interview on CBS' Face The Nation.

"We're nearing a pivot point in this," Klain said.

While there are currently no Ebola cases in the United States, Klain said the battle won't be fully won until there are zero cases in West Africa.

"You have to separate where we are here at home and over in West Africa," Klain said. "Here at home, we've made significant strides to prepare for the occasional case of Ebola that we will see from time to time on our shores."

Klain added that "the number of new cases overall in West Africa has somewhat stabilized. But this won't be done 'til we get all the way to zero.

"It's like a forest fire -- few embers burning, and the thing can reignite at any time."

Klain also reported that a lab technician at the U.S. Centers for Disease Control and Prevention who may have been accidentally exposed to the virus has shown no signs of actually contracting the disease.

"Thanks to the other protocols and procedures in place, there is no risk to the public, no risk to the CDC campus generally" in this incident, Klain said.