FIG. 3.

The genetic diversity dynamics of EV-71 genogroups B and C. (A) Bayesian skyline plot estimates depicting the past genetic diversity dynamics through time of EV-71 genogroups B and C. The plot for genogroup B shows a sharp rise in relative genetic diversity in the late 1990s. Other increases can be seen in the early 1970s and mid-1980s. The putative EV-71 subgenogroups that are proposed to be implicated in escalating genetic diversity are indicated by arrows. Similarly, the plot for genogroup C shows sharp rises in genetic diversity in the mid-to-late 1980s and late 1990s. (B) The global reporting of EV-71 infections from the 1970s to 2008, compiled from the published literature (see Table S4 in the supplemental material), suggests that at least three independent waves of major outbreaks—one in each decade—have occurred worldwide since 1970. These episodes of outbreaks are indicated by gray shading in all plots. Country names are abbreviated as follows: US, United States; AU, Australia; JP, Japan; BU, Bulgaria; FR, France; HK, Hong Kong; TW, Taiwan; MY, Malaysia; SG, Singapore; CN, China; KR, Republic of Korea; VN, Viet Nam; HU, Hungary; MN, Mongolia; BN, Brunei.