Abstract
The members of the genus Hantavirus are the only representatives of the family Bunyaviridae not transmitted by arthropod vectors but by small mammals. Hantaviruses transmitted by rodents (Order Rodentia) have been discovered at first because of their pathogenicity for humans. The first phylogenetic studies suggested a co-evolution between each hantavirus and its rodent reservoir species. However, further exploration of more animal reservoirs has evidenced that hantaviruses also circulate among insectivores (Order Soricomorpha) and bats (Order Chiroptera), without associated human pathology or even transmission demonstrated up to now. Documented co-circulation of the same hantavirus among sympatric rodent species and new phylogenetic data outlining host-switching events between closely related hantaviruses are currently weakening the concept of strict co-speciation. In addition, the closer analysis of clinical cases invites to moderate the dogma of a clearly distinct pathology in humans between Old World (Europe-Asia) hantaviruses that would provoke Haemorrhagic Fevers with Renal Syndrome (HFRS) and New World (Americas) hantaviruses that would result in a Cardio- Pulmonary Syndrome (HCPS). These topics are discussed because they open interesting perspectives for trans-disciplinary research, from compared immunology between mammals up to modelling of reservoir dynamics in natural environment and sociology of human populations at risk. The most recent data concerning the circulation and pathogenicity of hantaviruses in Europe and in the world are also presented as well as the new technologies for the serological and genetic investigations to discover without a priori new viruses « sleeping » in animal reservoirs and to evaluate their potential for future emergence(s) in man