Parvoviridae, a diverse family of small single-stranded DNA viruses was established in 1975. It was divided into two subfamilies, Parvovirinae and Densovirinae, in 1993 to accommodate parvoviruses that infect vertebrate and invertebrate animals, respectively. This relatively straightforward segregation, using host association as the prime criterion for subfamily-level classification, has recently been challenged by the discovery of divergent, vertebrate-infecting parvoviruses, dubbed “chapparvoviruses”, which have proven to be more closely related to viruses in certain Densovirinae genera than to members of the Parvovirinae. Viruses belonging to these genera, namely Brevi-, Hepan- and Penstyldensovirus, are responsible for the unmatched heterogeneity of the subfamily Densovirinae when compared to the Parvovirinae in matters of genome organization, protein sequence homology, and phylogeny. Another genus of Densovirinae, Ambidensovirus, has challenged traditional parvovirus classification, as it includes all newly discovered densoviruses with an ambisense genome organization, which introduces genus-level paraphyly. Lastly, current taxon definition and virus inclusion criteria have significantly limited the classification of certain long-discovered parvoviruses and impedes the classification of some potential family members discovered using high-throughput sequencing methods. Here, we present a new and updated system for parvovirus classification, which includes the introduction of a third subfamily, Hamaparvovirinae, resolves the paraphyly within genus Ambidensovirus, and introduces new genera and species into the subfamily Parvovirinae. These proposals were accepted by the ICTV in 2020 March.

细小病毒科是1975年建立的小型单链DNA病毒的不同家族。1993年将细小病毒科分为细小病毒科和反病毒科两个亚科，以容纳分别感染脊椎动物和无脊椎动物的细小病毒。使用宿主关联作为亚家族水平分类的主要标准，这种相对简单的分离最近受到发现被称为“ chapparvoviruses”的脊椎动物感染的细小病毒的分歧的挑战，这种细小病毒已证明与某些病毒更紧密相关Densovirinae属比Parvovirinae的成员要高。属于这些属的病毒，即Brevi-，Hepan-和Penstyldensovirus，负责亚科的无与伦比的异质性浓核病毒亚科相比时，细小病毒的基因组结构，蛋白质序列同源性，系统发育和事项。登革病毒科的另一种，两足动物病毒，它挑战了传统的细小病毒分类，因为它包括所有新发现的具有歧义基因组结构的densoviruses，从而引入属水平的副植物。最后，当前的分类单元定义和病毒包含标准已大大限制了某些长期发现的细小病毒的分类，并阻碍了使用高通量测序方法发现的某些潜在家族成员的分类。在这里，我们介绍了细小病毒分类的一个新的和更新的系统，其中包括引入了第三个亚科Hamaparvovirinae，解决了Ambidensovirus属的副生菌，并将新的属和种引入了细小病毒亚科。这些建议在2020年3月被ICTV接受。