It claimed the lives of more than 11,000 people, infected thousands more, and had world leaders scrambling to control it, but on Thursday, the worst Ebola outbreak in history was officially declared over in West Africa.
After 42 days passed without a new case arising—the criteria for considering a region disease-free—the World Health Organization on Thursday announced the end of the Ebola scare in Liberia. The nation hit hardest by the epidemic was first declared Ebola-free in May, but the virus reappeared twice, with the latest case confirmed in November. That patient has since tested negative for Ebola on two occasions.
“Detecting and breaking every chain of transmission has been a monumental achievement,” said WHO Director-General Margaret Chan in a statement on Thursday. “So much was needed and so much was accomplished by national authorities, heroic health workers, civil society, local and international organizations, and generous partners.”
WHO officials did warn of potential flare-ups in their Thursday announcement, and as if to prove their point, just hours later the news broke that Sierra Leone had confirmed a death from Ebola.
“The risk of reintroduction of infection is diminishing as the virus gradually clears from the survivor population, but we still anticipate more flare-ups and must be prepared for them,” said Bruce Aylward, WHO’s special representative for the Ebola Response.
Aylward says efforts are underway to ensure all measures to monitor the disease are carried out in Guinea, Liberia, and Sierra Leone—the three countries affected most by the outbreak—by the end of March. Strong response teams and effective surveillance will be necessary to make sure the virus remains dormant.
Here’s a look back at the epidemic that caused such panic and heartbreak in one of the world’s poorest regions, and the response from the international community.