This Ebola outbreak raises questions about when it all began — and the U.S. response

The sheer number of cases and deaths are a sign that the outbreak might have been smoldering before the virus was identified.

The sheer number of cases and deaths are a sign that the outbreak might have been smoldering before the virus was identified.

The sheer number of cases and deaths are a sign that the outbreak might have been smoldering before the virus was identified.