ABSTRACT: SYNOPSIS: (Figure is included in full-text article.)The severe Ebola virus disease epidemic occurring in West Africa likely stems from a single zoonotic transmission event involving a 2-year-old boy in Meliandou, Guinea, who might have been infected by hunting or playing with insectivorous free-tailed bats living in a nearby hollow tree. : The severe Ebola virus disease epidemic occurring in West Africa likely stems from a single zoonotic transmission event involving a 2-year-old boy in Meliandou, Guinea, who might have been infected by hunting or playing with insectivorous free-tailed bats living in a nearby hollow tree.(Figure is included in full-text article.)