The terminal hairpins of the HBoV1 genome are typical of those of the genus Bocavirus A head-to-tail junction of an HBoV1 episome identified in an HBoV1-infected HAE [28, 29] was found to possess two sequences (39-CGCGCGTA-59 and 39-GATTAG-59) identical to parts of the BPV1 left-end hairpin (LEH) [27, 32] . This finding suggested that the head sequence is part of the HBoV1 LEH (nucleotides in blue; Figure 1A ). We therefore used the head sequence as the 39 end of a reverse primer (RHBoV1_LEH). Together with a forward primer (FHBoV1_nt1), which anchors the 39 end of the HBoV1 genome predicted from the BPV1 LEH, we amplified the hairpin of the LEH from a viral DNA extract (1.2610 8 gc/ml) prepared from a nasopharyngeal aspirate taken from an HBoV1-infected patient (HBoV1 Salvador1 isolate) [17] . Only one specific DNA band was detected at approximately (,)150-bp ( Figure 1D , lane 1). Sequencing of this DNA revealed a novel sequence of the HBoV1 LEH (nucleotides in red between the two arrows; Figures 1A and S1A). Because the LEHs of the prototype bocaviruses BPV1 and MVC are asymmetric [27, 32] , we set up another PCR reaction with a forward primer located in the hairpin (FHBoV1_LEH) and a reverse primer targeting a sequence downstream of the LEH at nt 576 (RHBoV1_nt576; Figure 1B ). Sequencing of a DNA fragment ( Figure S1B ), detected as expected as a ,600-bp band ( Figure 1D, lane 3) , confirmed the presence of the novel joint sequence and the LEH ( Figure 1B) .