We report on a previously uncharacterized species of human bocavirus which we tentatively named HBoV4. HBoV1, HBoV2, and HBoV3 were also detected using a pan-PCR approach. HBoV2 has been detected in the stool of Pakistani children [7] and HBoV3 in stool samples of Australian children [8] , and both were recognized as recombinant viruses. The newly reported Australian HBoV3 (EU918736) is closely related to a Tunisian strain (TA-210-07) (Figure 2) . A highly prevalent genotype of HBoV2 (HBoV2B), together with partial genomic support for second genotypes of HBoV3 and HBoV4, were also identified. The availability of novel bocavirus genomes will allow the design of species-specific PCR or microarray oligonucleotides for their detection and for the disease association studies that are now required for the 3 recently characterized enteric human bocavirus species (HBoV2, HBoV3, and HBoV4). Based on the phylogenetic clustering observed for a large number of partial VP1 sequences ( Figure 1 ) and the distances among full genomes (Table 2) , we propose for future classification that HBoV strains showing 18% protein and 110% nucleotide difference in the complete VP1 gene should be considered different species, whereas those showing 11.5% protein and 15% nucleotide difference should be considered different genotypes. This VP1-based classification retains the 4 proposed human bocavirus species. The VP1 locus was selected because it is likely to strongly influence tissue tropism and potentially pathogenesis [42] .