Researchers from the Robert Koch Institute believe that the index case was a two-year-old boy who lived in the remote village of Meliandou, Guéckédou located in the Nzérékoré Region of Guinea. Researchers believe that the boy was said to have contracted the virus while he was playing near a tree that was a roosting place for free-tail bats infected with the virus. Dr. Fabian Leendertz, an epidemiologist who was part of the investigative team, said Ebola virus is transmitted to humans either through contact with larger wildlife or by direct contact with bats. The boy, later identified as Emile Ouamouno, fell ill on 2 December 2013 and died four days later. The boy's sister fell ill next, followed by his mother and grandmother. It is believed the Ebola virus later spread to the villages of Dandou Pombo and Dawa, both in Guéckédou, by the midwife who attended the boy. From Dawa village the virus spread to Guéckédou Baladou District and Guéckédou Farako District, and on to Macenta and Kissidougou.
Although Ebola represents a major public health issue in sub-Saharan Africa, no cases had ever been reported in West Africa and the early cases were diagnosed as other diseases more common to the area such as Lassa fever, another hemorrhagic fever similar to Ebola. Thus, it was not until March 2014 that the outbreak was recognized as Ebola. The Ministry of Health of Guinea notified the World Health Organization (WHO), and on 23 March the WHO announced an outbreak of Ebola virus disease in Guinea with a total of 49 cases as of that date. By late May, the outbreak had spread to Conakry, Guinea's capital, a city of about two million inhabitants.