Ebola virus disease

Chart: Ebola cases and confirmed deaths in Africa

Data: DRC Ministry of Health; Chart: Andrew Witherspoon, Harry Stevens/Axios

The world's second-largest Ebola outbreak on record is underway in the Democratic Republic of the Congo, and entered an ominous phase this week with the spread of the virus into Uganda.

What to watch: The World Health Organization and aid groups are pouring resources into the region to try to contain it, but the longer this Ebola outbreak continues, the greater the likelihood it will spread to other highly populated areas within the country, move to other neighboring countries or even internationally.

Ebola spreads, as world awakens

Data: DRC Ministry of Health; Chart: Andrew Witherspoon, Harry Stevens/Axios

The long-simmering Ebola outbreak in the Democratic Republic of the Congo entered a new and more ominous phase this week, with the cross-border spread of a handful of cases into western Uganda.

Why it matters: The cross-border spread puts more pressure on the World Health Organization to declare the nearly yearlong outbreak a public health emergency, which it has proven reluctant to do. A committee will meet Friday to determine whether to take that step.