Speaking before Congress, the vice president of program and government relations for the Christian aid group, Ken Isaacs, criticised the lack of response from the U.S. until two of its own citizens contracted the lethal disease. He is now warning that a more serious approach is needed in order to contain it.
"It took two Americans getting the disease in order for the international community and the United States to take serious notice of the largest outbreak of the disease in history," he said.
"[Now] the disease is out of control," Isaacs warned. "If we don't fight and contain this in Africa we will be fighting to contain this around the world."
The outbreak began in eastern Guinea and has now spread to its neighbouring countries, with Nigeria and Liberia declaring a state of national emergency earlier this week.
Meanwhile, the Zambian government has prohibited anyone arriving from affected countries to enter its borders.
A report by the World Health Organization confirmed the death of over 900 people since the outbreak in December 2013, with more than 1,700 still infected. Left untreated, around 90% of people infected with Ebola will die.