Generations ago, families fleeing tribal violence in southern Guinea settled in a lush, humid forest. They took solace among the trees, which offered cover from intruders, and carved a life out of the land. Their descendants call it Meliandou, which elders there say comes from words in the Kissi language that mean “this is as far as we go.”
By 2013, a village had bloomed where trees once stood — 31 homes, surrounded by a ring of forest and footpaths that led to pockets residents had cleared to plant rice. Their children played in a hollowed-out tree that was home to a large colony of bats.
Nobody knows exactly how it happened, but a virus that once lived inside a bat found its way into the cells of a toddler named Emile Ouamouno. It was Ebola, which invades on multiple fronts — the immune system, the liver, the lining of vessels that keep blood from leaking into the body. Emile ran a high fever and passed stool blackened with blood as his body tried to defend against the attack. A few days later, Emile was dead.
On average, only half of those infected by Ebola survive; the rest die of medical shock and organ failure. The virus took Emile’s 4-year-old sister and their mother, who perished after delivering a stillborn child. Emile’s grandmother, feverish and vomiting, clung to the back of a motorbike taxi as it hurtled out of the forest toward a hospital in the nearest city, Guéckédou, a market hub drawing traders from neighboring countries. She died as the virus began its spread.
Emile was patient zero in the worst Ebola outbreak the world has ever seen. The virus infiltrated 10 countries, infected 28,600 people and killed more than 11,300. Health care workers clad head to toe in protective gear rushed to West Africa to treat the sick and extinguish the epidemic, an effort that took more than two years and cost at least $3.6 billion. Then, the foreign doctors packed up and the medical tents came down.
This has long been the way the world deals with viral threats. The institutions we trust to protect us, from the World Health Organization to U.S. agencies like the Centers for Disease Control and Prevention, focus on responding to epidemics — fighting the fires once they have begun, as if we could not have predicted where they would start or prevented them from sparking.
But looking back, researchers now see that dangerous conditions were brewing before the virus leaped from animals to humans in Meliandou, an event scientists call spillover.
The way the villagers cut down trees, in patches that look like Swiss cheese from above, created edges of disturbed forest where humans and infected animals could collide. Rats and bats, with their histories of seeding plagues, are the species most likely to adapt to deforestation. And researchers have found that some bats stressed out by habitat loss later shed more virus.
Researchers considered more than 100 variables that could contribute to an Ebola outbreak and found that the ones that began in Meliandou and six other locations in Uganda and the Democratic Republic of Congo were best explained by forest loss in the two years leading up to the first cases.
It is now clear these landscapes were tinderboxes for the spillover of a deadly virus.
We wondered what the world had done to keep disaster from striking again. Had global health leaders channeled money into stopping tree loss or deployed experts to help communities learn how to sustain themselves without cutting down the forest?
To get a sense of the current risk of spillover from deforestation at these sites, ProPublica consulted with a dozen researchers for its own analysis, which was unprecedented in its quest for specific, real-world findings. Using a theoretical model developed by a team of biologists, ecologists and mathematicians, we applied data on tree loss from historical satellite images taken between 2000 and 2021 — the most recent year available — and tested tens of thousands of infection scenarios.
The results were alarming: We found that the same dangerous pattern of deforestation has increased around Meliandou in the past decade, putting its residents at a greater risk of an Ebola spillover than they faced in 2013, when the disease first ravaged their village.
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Additional reporting by Lisa Song and Robin Fields (ProPublica)
