Summary

Viral hemorrhagic fever (VHF) is an infectious syndrome in humansoften associated with high fatality rates. For most VHFsthere are no specific and effective therapies or vaccines availableand, in general, there is a lack of knowledge regarding the biologyand pathogenesis of the causative agents.Therefore, a moredetailed understanding of the molecular basis ofVHF pathogenesis,including the identification of viral virulence determinantsand host interactions and responses, will be important to enhance our ability to control VHF infections.The recently developed“reverse genetics systems” for severalVHF causing viruseshave allowed the generation of infectious viruses from clonedcDNA and thus, the generation of virus mutants. Here we reviewthe existing reverse genetics systems for VHF causing virusesand discuss their use in studying viral replication, pathogenesis,and the development of antivirals and vaccines.