Molecular epidemiology and evolution of worldwide enterovirus 71 strains isolated from 1970 to 2004

Human enterovirus 71 （EV71） is one of the major etiological agents of the hand-foot-and-mouth disease （HFMD） that often causes severe neurological complications. Recently, its outbreaks mainly take place in the torrid zone of the Asia-Pacific region. To study the evolution and genetic variability, we collected 532 EV71 strains with almost complete or complete VP1 sequences （891 nt） isolated worldwide from 1970 to 2004. The pairwise homologies and genetic distances were analyzed. Most strains belong to previously identified genotype B and C. However, a unique strain R13223-1ND-01 appears not to fall into current three genotypes （A, B and C）, and probably represents a new genotype D. Some orphan strains were observed in the genotypes B and C, and their significance in the EV71 evolution was discussed. Moreover, there is a significant co-variance of 6 discrete positions on VP1 （amino acid 43, 58, 164, 184, 240 and 249）. This high co-variability is tightly related with the subgenotypes.

Molecular epidemiology and evolution of worldwide enterovirus 71 strains isolated from 1970 to 2004

Human enterovirus 71 (EV71) is one of the major etiological agents of the hand-foot-and-mouth disease (HFMD) that often causes severe neurological complications. Recently,its outbreaks mainly take place in the torrid zone of the Asia-Pacific region. To study the evolution and genetic variability,we collected 532 EV71 strains with almost complete or complete VP1 sequences (891 nt) isolated worldwide from 1970 to 2004. The pairwise homologies and genetic distances were analyzed. Most strains belong to previously identified genotype B and C. However,a unique strain R13223-IND-01 appears not to fall into current three genotypes (A,B and C),and probably represents a new genotype D. Some orphan strains were observed in the genotypes B and C,and their significance in the EV71 evolution was discussed. Moreover,there is a significant co-variance of 6 discrete positions on VP1 (amino acid 43,58,164,184,240 and 249). This high co-variability is tightly related with the subgenotypes.