Sequencing the genome of Ebola virus strains circulating in Guinea has allowed scientists at the Institut Pasteur in Dakar and in Paris, the CNRS and the University of Sydney to retrace the spread of the virus and monitor its evolution in the country where the outbreak started. This research reveals the co-circulation in Guinea, particularly in the urban regions of the capital and neighboring towns, of three distinct variants of the virus whose mutations are described in an article published in Nature.