In 1976, in the villages located on the banks of the river Ebola, a tributary of the Congo river, an extremely aggressive virus started two contemporary outbreaks of Ebola: one in the Democratic Republic of the Congo and the other in South Sudan.
This organism caused a series of rapidly worsening signs and symptoms, attributable to the complex of viral haemorrhagic fevers . Ebola was similar to another known virus, Marburg (both belong to the Filoviridae family and cause similar problems) and from the blood and cell culture analyzes it turned out that it was not even yellow fever or Lassa fever .
Ebola is very infectious and virulent: five or ten virus particles are enough to start an explosive reproduction inside the host organism, often fatal. The genetic material consists of a single strand of RNA (in practice, it is organized in a string that provides instructions on how to assemble copies of the virus itself). So far five different strains of the virus have been isolated, four of which are able to infect humans.
In the past, the virus has caused several epidemics, but always on a smaller scale than today. Although Ebola has always spread extremely rapidly, it was once confined to villages in central and western Africa, close to the rainforest, without exceeding 500 victims.
