In February 2019, following the annual taxon ratification vote, the order Bunyavirales was amended by creation of two new families, four new subfamilies, 11 new genera and 77 new species, merging of two species, and deletion of one species. This article presents the updated taxonomy of the order Bunyavirales now accepted by the International Committee on Taxonomy of Viruses (ICTV).

Several human diseases in Europe are caused by viruses transmitted by tick bite. These viruses belong to the genus Flavivirus, and include tick-borne encephalitis virus, Omsk haemorrhagic fever virus, louping ill virus, Powassan virus, Nairovirus (Crimean-Congo haemorrhagic fever virus) and Coltivirus (Eyach virus). All of these viruses cause more or less severe neurological diseases, and some are also responsible for haemorrhagic fever. The epidemiology, clinical picture and methods for diagnosis are detailed in this review. Most of these viral pathogens are classified as Biosafety Level 3 or 4 agents, and therefore some of them have been classified in Categories A-C of potential bioterrorism agents by the Centers for Disease Control and Prevention. Their ability to cause severe disease in man means that these viruses, as well as any clinical samples suspected of containing them, must be handled with specific and stringent precautions.

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

SUMMARYMonoclonal antibodies prepared against vaccine strains of yellow fever (YF) virus were initially characterized by fluorescence microscopy of Vero cells infected with YF virus strain 17D. When similarly tested against representatives of all flavivirus subgroups, the antibodies produced a wide spectrum of reactions ranging from the monospecific to the broadly cross-reactive; at least five antigenic domains in the YF virus envelope glycoprotein were identified. Monoclonal antibodies differentiated between YF virus vaccine strains (17D, 17DD, FNV), wild-type viruses and plaque variants selected from a 17D pool. One isolate from a patient with YF was antigenically similar to the Brazilian vaccine strain 17DD. Several of the antibodies reacting with the YF viral envelope glycoprotein in biological tests identified the 54K envelope glycoprotein; 45K and 26K polypeptides in YF 17D virus-infected cells were also identified by radioimmunoprecipitation and polyacrylamide gel electrophoresis. Neither of these polypeptides was found in uninfected cells. They may represent shortlived precursors of the 54K protein, post-translational cleavage or breakdown products. Other antibodies reacted with a 48K polypeptide in virus-infected cell lysates. This may be the non-structural NV3 protein described for YF virus. Its appearance on the surface of unfixed infected cells, but not on released virions, was demonstrated by fluorescence microscopy.

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