The PHEIC development on Ebola signals a heightened state of alert, calling for international coordination, and it comes as the 79th World Health Assembly starts in Geneva, on Monday.

Officials suspect the disease has caused 80 deaths in the Democratic Republic of Congo so far.

WHO declared the Bundibugyo Ebola outbreak a PHEIC just 48 hours after confirmation, the fastest such designation in history. What drove the decision.