Classification of papillomaviruses

One hundred eighteen papillomavirus (PV) types have been completely described, and a yet higher number of presumed new types have been detected by preliminary data such as subgenomic arnplicons. The classification of this diverse group of viruses, which include important human pathogens, has been debated for three decades. This article describes the higher-order PV taxonomy following the general criteria established by the International Committee oil the Taxonomy of Viruses (ICTV), reviews the literature of the lower order taxa, lists all known "PV types", and interprets their phylogenetic relationship. PVs are a taxonomic family of their own Papillomaviridae, unrelated to the polyomaviruses. Higher-order phylogenctic assemblages of PV types, such as the "genital human PVs", are considered a genus, the latter group, for example, the genus "Alpha-Papillomavirus". Lower-order assemblages of PV types within each genus are treated as species because they are phylogenetically closely related, but while they have distinct genomic sequences, they have identical or very similar biological or pathological properties. The taxonomic status of PV types, subtypes, and variants remains unchanged and is based oil the traditional criteria that the sequence of their L I genes should be at least 10%, 2-10%, and maximally 2% dissimilar from one another. (C) 2004 Elsevier Inc. All rights reserved.