Beginning in october the 14th 1987, an epidemic spread over southern Mauritania during two months. Initially thought to be Yellow fever outbreak, the cause was soon realised to another arbovirus, Rift valley fever virus. The large number of patients ans severity of hospitalized cases required a complete reorganization of hospital running. A team was created to analyse differents aspects of this epidemic, particulary about several points which had not been clarified. Distress did not appear in population of the concerned area, even if spectacular deaths occurred and were observed by everyone. Knowledge acquired during the management of this outbreak emphasized multidisciplinary team work. This team should be composed od physicians, biologists, epidemiologists, entomologists, data processing expert and technicians. Physician have to know disaster medical organization. The absence of one of these member could lead to a lack of information and incomplete understanding of the arboviral epidemic.