TAXONOMY OF AFRICAN HORSE SICKNESS VIRUSES

Nine distinct genera are currently recognised within the virus family Reoviridae, which include a total of 63 virus groups or species (speci es = virus group = electropherotype or serogroup), comprising 214 viru s serotypes or subtypes, as well as 20 provisional types or subtypes, most of which (149 + 9 tentative) are assigned to the genus Orbivirus [5, 9, 16]. The 19 species of orbiviruses (serogroups), were establish ed principally on antigenic (serologic) grounds but many of these plac ements have been supported by molecular analyses. This introductory pa per defines the taxonomy and classification of these viruses and estab lishes guidelines for use in other papers to be presented at this symp osium and elsewhere.