Abstract

A decade ago nairoviruses were the least understood members of the Bunyaviridae family. Today this situation is totally different, with huge advances having been made in the field. These have been in three major areas: (1) sequencing complete genomes, as well as conserved regions of additional viruses, thus allowing phylogenetic analysis, (2) understanding the processes of glycoprotein processing and (3) dissecting three ways in which these viruses avoid the innate immune response, viz. removal of 5' triphosphate groups from viral RNAs to avoid RIG-I activation, the action of the OTU domain in the viral polymerase and delaying activation of the interferon pathway. In addition, two new viruses have been discovered, Kupe virus and Finch Creek virus. However, fundamental gaps in our knowledge still remain. The difficulty of manipulating the viruses through reverse genetic experiments has hampered our understanding of the processes of transcription and replication, and individual gene function. Much also remains to be learnt in terms of pathogenesis, and in particular the genomic regions required to induce severe disease, as well as in the area of vector interactions, drug therapy and vaccine design. If current progress continues, the next decade will provide many more exciting insights.