Molecular Evidence of Persistent Epidemic and Evolution of Subgenotype B1 Coxsackievirus A16-Associated Hand, Foot, and Mouth Disease in China

The molecular epidemiology of CVA16 in China between 1999 and 2008 reflects a pattern of endemic cocirculation of clusters B1a and B1b within subgenotype B1 viruses. The annual evolution rate of CVA16 was estimated as approximately 0.91 x 10(-2) substitutions per synonymous nucleotide/year and is slightly lower than that of HEV71.