[Rift Valley fever virus infection : physiopathology and pathogenesis].

Rift Valley fever (RVF) is a major emerging arboviral disease with a complex epidemiological cycle. RVF virus (RVFV) is transmitted by mosquito vectors to ruminants, causing epizootics, and then from animals to humans, triggering epidemics. During its cycle, RVFV infects a wide range of hosts, but the associated pathogenesis has yet to be elucidated. RVFV displays a predominant hepatic tropism, but also has a multicellular tropism inducing physiopathological effects in several tissues. However, there is variability between species in terms of physiopathology : a common clinical picture is found (severe hepatitis, hemorrhages, leukopenia), but certain forms are mainly found in humans (neurological and ocular damage) or in ruminant herds (waves of abortions). Although the molecular mechanisms involved are still poorly understood, it seems that early inflammatory response is related to the severity of the pathology. A better understanding of the pathogenesis of RVFV seems essential, especially since no specific treatment exists to date.