Despite effective vaccines and treatments that dramatically boosted survival rates when administered early, the outbreak dragged on as first responders struggled to gain access to virus hotspots in Congo’s restive eastern borderlands.

As that outbreak neared its end, another one was declared on June 1 in the western city of Mbandaka, more than 1,000 km (620 miles) away. Genetic testing revealed the two epidemics were not connected.

“The health ministry intends to capitalise on the lessons learned and the success factors from this long epidemic to assure the most effective response possible in Mbandaka,” Health Minister Eteni Longondo told reporters.

There were 3,463 cases confirmed and probable cases recorded over the course of the outbreak in eastern Congo, including 2,277 deaths, Longondo said.

The largest Ebola outbreak occurred in West Africa from 2013-2016, when more than 11,300 people died from the disease in Guinea, Liberia and Sierra Leone. (Reporting by Stanis Bujakera and Hereward Holland; Editing by Aaron Ross, William Maclean)