In a press conference at CDC headquarters in Atlanta on Tuesday, health authorities said that between 550,000 and 1.4 million people could be infected in the countries that have been hit hardest -- Liberia and Sierra Leone -- if additional measures were not taken.
CDC projections are based on a report published last month before the US government approved sending 3,000 troops to West Africa, where at least 2,802 people have died of the Ebola virus.
Between 550,000 and 1.4 million people could be infected
"The model shows -- and I don't think this has been shown by other modeling tools out there-- that a surge now can break the back of the epidemic. It also shows that there are severe costs of delay," CDC Director Thomas Frieden said.
The CDC report also said that the estimated figures could be reversed if at least 70 percent of the people infected with the virus are treated under adequate conditions in medical centres.
"It is still possible to reverse the epidemic, and we believe this can be done if a sufficient number of all patients are effectively isolated, either in Ebola treatment units or in other settings, such as community-based or home care," Frieden said.
The CDC currently has 120 experts in the West Africa region helping to identify new cases and isolate them to stop more people from being infected, he said.