[Lassa, Marbourg and Ebola viruses: new features of African tropical pathology. II. Epidemiology. Public health problems (author's transl)].

Lassa, Marbourg and Ebola viruses are characterised by their endemo-epidemicity in tropical Africa, by their potential of inter-human transmission, by their gravity (30 to 50% mortality in cases admitted to hospital) and by the difficulty of their aetiological diagnosis. This results in a public health problem for countries in non-endemic regions receiving travellers coming from Africa. This problem is related to the risk of importation of cases, a risk which should not be exaggerated but nor should it be underestimated. Appropriate measures may be suggested in the light of assessment of the risk: organisation of specialised hospital facilities, laboratory and coordination service.