We applied an NGS based target capture approach to amplify HPgV-2 sequences from metagenomic libraries and enable full genome characterization. Despite expanded geographical sampling, sequence variability remains low, with diversity concentrated in approximately 3.3% of all amino acids. Serial samples from one HPgV-2 positive individual co-infected with comparable titers of HIV, HCV, and GBV-C showed that HPgV-2 remains highly stable over several weeks compared to other RNA viruses, despite a similarly error-prone polymerase. The consistent epidemiological association with and structural similarities to HCV, and the weak positive correlation of HCV and HPgV-2 titers shown here, suggests it may benefit from co-infection. While minimal selective pressure on HPgV-2 to evolve could suggest fitness, the rarity of HPgV-2 and the tight phylogenetic clustering of global strains likely indicates origination from a common source and a virus that is ill-suited to its host. Sporadic infections may explain the limited genetic diversity observed worldwide.

我们应用了基于NGS的靶标捕获方法，从宏基因组库中扩增HPgV-2序列，并实现了全基因组表征。尽管扩大了地理采样范围，但是序列变异性仍然很低，多样性集中在所有氨基酸的约3.3％中。来自一个HPgV-2阳性个体的连续样本与HIV，HCV和GBV-C的可比效价共同感染，显示HPgV-2与其他RNA病毒相比在数周内保持高度稳定，尽管聚合酶同样容易出错。此处显示的与HCV一致的流行病学关联和结构相似性，以及HCV和HPgV-2滴度的弱正相关性，表明它可能受益于合并感染。虽然对HPgV-2进化的最小选择性压力可能表明身体健康，HPgV-2的稀有性和全球菌株的紧密系统发生簇很可能表明其起源于共同的来源和一种不适合其宿主的病毒。零星的感染可能解释了全世界观察到的有限的遗传多样性。