Patient Zero in the Ebola outbreak, researchers suspect, was a 2-year-old boy who died on Dec. 6, just a few days after falling ill in a village in Guéckédou, in southeastern Guinea. Bordering Sierra Leone and Liberia, Guéckédou is at the intersection of three nations, where the disease found an easy entry point to the region.
A week later, it killed the boy’s mother, then his 3-year-old sister, then his grandmother. All had fever, vomiting and diarrhea, but no one knew what had sickened them.
Two mourners at the grandmother’s funeral took the virus home to their village. A health worker carried it to still another, where he died, as did his doctor. They both infected relatives from other towns. By the time Ebola was recognized, in March, dozens of people had died in eight Guinean communities, and suspected cases were popping up in Liberia and Sierra Leone — three of the world’s poorest countries, recovering from years of political dysfunction and civil war.