Human viruses: discovery and emergence

Woolhouse, Mark; Scott, Fiona; Hudson, Zoe; Howey, Richard; Chase-Topping, Margo

Of course, not all newly identified human virus species are 'new' in the sense that they have only recently started to infect humans; many of them have been present in humans for a considerable time but have only recently been recognized (see [2] for a more detailed discussion). Moreover, we recognize that 'species' itself is an imprecise designation, especially for viruses such as influenza A where different serotypes can have very different epidemiologies and health impacts. Indeed, the demarcation between genus, species complex, species and serotype (or other designations of subspecific variation) can be somewhat arbitrary. Nonetheless, a study of currently recognized 'species' is a natural starting point for attempts to characterize and interpret patterns of virus diversity.