Contact tracing is improving. Treatments may be months away. Here’s what could determine whether a fast-expanding outbreak can be slowed down.

Health workers have warned that the outbreak, already one of the worst in decades, could take as long as a year to contain if infection rates do not flatten.

The vaccine development process and coordination between health organizations have improved since a devastating 2014-2016 outbreak.

China is well positioned to help stop the deadly virus, and could move into a gap left by U.S. retreat.

Mining has been the lifeblood of this remote Congolese hill town for decades. Now, it is fueling the spread of a devastating virus.

A remote gold mining town is under siege, as medical workers struggle to beat back a surge of deaths and infections.

Uganda said that flights to and from the Democratic Republic of Congo would be temporarily suspended, as the outbreak appeared to spread to a rebel-controlled province in Congo.

To some Africans, the claim that the continent’s largest health agency had already bungled its response scratched a familiar wound.