The spillover at Mayibout 2 was no isolated event. It was part of a pattern of disease outbreaks across Central Africa—a pattern of which the meaning is still a matter of puzzlement and debate. The disease in question, once known as Ebola hemorrhagic fever, is now simply called Ebola virus disease. The pattern stretches from 1976 (the first recorded emergence of Ebola virus) to the present, and from one side of the continent (Côte d’Ivoire) to the other (Sudan and Uganda). The four major lineages of virus that
