“If we have a sudden explosion in the number of cases we will need about a month of very limited travel and a ban on group meetings in order to let the disease burn itself out.”
But that is assuming that there’s no animal carrier as you pointed out in yourself:
“As long as there is no ‘reservoir animal’ in the U.S.”
Many bats eat flies. And vampire bats suck the blood of animals such as cattle. One fly on vomit, and there’s at least one slight risk of a long term problem.
The reservoir animals in Africa are some Pteropodidae fruit bats along with some primates and a small antelope. Ebola gets passed along to the human population when these animals get handled and eaten as ‘bush meat’.