Research and Diagnostics Center, Centers for Disease Control, Taipei, Taiwan.
PLoS One. 2013 Apr 16;8(4):e61957. doi: 10.1371/journal.pone.0061957. Print 2013.
The evolution and population dynamics of human influenza in Taiwan is a microcosm of the viruses circulating worldwide, which has not yet been studied in detail. We collected 343 representative full genome sequences of human influenza A viruses isolated in Taiwan between 1979 and 2009. Phylogenetic and antigenic data analysis revealed that H1N1 and H3N2 viruses consistently co-circulated in Taiwan, although they were characterized by different temporal dynamics and degrees of genetic diversity. Moreover, influenza A viruses of both subtypes underwent internal gene reassortment involving all eight segments of the viral genome, some of which also occurred during non-epidemic periods. The patterns of gene reassortment were different in the two subtypes. The internal genes of H1N1 viruses moved as a unit, separately from the co-evolving HA and NA genes. On the other hand, the HA and NA genes of H3N2 viruses tended to segregate consistently with different sets of internal gene segments. In particular, as reassortment occurred, H3HA always segregated as a group with the PB1, PA and M genes, while N2NA consistently segregated with PB2 and NP. Finally, the analysis showed that new phylogenetic lineages and antigenic variants emerging in summer were likely to be the progenitors of the epidemic strains in the following season. The synchronized seasonal patterns and high genetic diversity of influenza A viruses observed in Taiwan make possible to capture the evolutionary dynamic and epidemiological rules governing antigenic drift and reassortment and may serve as a "warning" system that recapitulates the global epidemic.
台湾地区人类流感的进化和种群动态是全球流行病毒的一个缩影，尚未得到详细研究。我们收集了 1979 年至 2009 年间在台湾分离的 343 株具有代表性的甲型流感病毒全基因组序列。系统进化和抗原性数据分析显示，H1N1 和 H3N2 病毒在台湾持续共同流行，尽管它们具有不同的时间动态和遗传多样性程度。此外，两种亚型的流感 A 病毒都经历了涉及病毒基因组所有 8 个片段的内部基因重配，其中一些重配也发生在非流行期间。两种亚型的基因重配模式不同。H1N1 病毒的内部基因作为一个整体移动，与共同进化的 HA 和 NA 基因分开。另一方面，H3N2 病毒的 HA 和 NA 基因往往与不同的内部基因片段一致分离。特别是随着重配的发生，H3HA 总是与 PB1、PA 和 M 基因一起作为一组分离，而 N2NA 则始终与 PB2 和 NP 一起分离。最后，分析表明，夏季出现的新系统发育谱系和抗原变异体可能是下一季流行株的前体。台湾地区甲型流感病毒同步的季节性模式和高遗传多样性使得捕捉到控制抗原漂移和重配的进化动态和流行病学规律成为可能，并且可能成为再现全球流行的“预警”系统。
