Ebola Virus Outbreak among Wild Chimpanzees Living in a Rain Forest of Cote d'Ivoire

Abstract

An outbreak of Ebola in nature is described for the first time.During a few weeks in November 1994, Ç25% of 43 members of a wild chimpanzee community disappeared or were found dead in the TaıF National Park, Co ˆte d'Ivoire.A retrospective cohort study was done on the chimpanzee community.Laboratory procedures included histology, immunohistochemistry, bacteriology, and serology.Ebola-specific immunohistochemical staining was positive for autopsy tissue sections from 1 chimpanzee.Demographic, epidemiologic, and ecologic investigations were compatible with a point-source epidemic.Contact activities associated with a case (e.g., touching dead bodies or grooming) did not constitute significant risk factors, whereas consumption of meat did.The relative risk of meat consumption was 5.2 (95% confidence interval, 1.3 -21.1).A similar outbreak occurred in November 1992 among the same community.A high mortality rate among apes tends to indicate that they are not the reservoir for the disease causing the illness.These points will have to be investigated by additional studies. National Science Foundation.the chimpanzees has centered on behavior and ecologic questions, Reprints or correspondence: Dr. Pierre Formenty, World Health Organizaand noninvasive observational methods have been used to follow tion, 01 BP 2494 Abidjan 01, Co ˆte d'Ivoire (formenty@globeaccess.net.target individuals on a daily basis from dawn to dusk [15].