Genetic Characterization Of EV71in The Northeastern Region Of China

Hand,foot and mouth disease is mainly affect the infants and young children inrecent years.It is caused by a variety of enterovirus,most patients had mild symptoms,but a small portion of them had the rapid progress of patient’s condition,even leadingto death.Using the real-time PCR method, we have detected253hand-foot-mouth disease(HFMD) cases collected in the Infectious Diseases Department of the First Hospital ofJilin University from August to October2010. Among all cases,196are positive inenterovirus with EV71infection accounting for about42.8%of the total number ofenterovirus infection, followed by CA16infection which is28.6%of the total number.By doing whole-genome phylogenetic analysis of three EV71virus strains fromChangchun and other types of enteroviruses,we reach the conclusion that both theEV71virus strains epidemic in Changchun and those epidemic in mainland China inrecent years are C4subtypes. However, with the same reference virus strains, whenwe do phylogenetic analysis of the VP1region, the results turn out to be differentfrom the whole-genome analysis,and this implies the genetic recombination of thevirus.In order to further validate the recombination of the virus,we have conductedsimilarity and recombination analysis of the three EV71virus strains from Changchunwith other subtypes of enterovirus and found that intra-group recombination andinter-group recombination do exist in P2and P3regions. Moreover,the phylogenetictree of5’UTR is quite different from that of the whole genome,which indicates thatthe recombination of virus is closely related to5’UTR.We haven’t detected enterovirus infection in22.5%of HFMD patients.Combining the phylogenetic analysis of5’UTR, we maintain that,besides the mostcommon EV71virus and CA16virus, the HFMD pathogens in Changchun also include other non-mainstream pathogens which are not been confirmed yet. While theconfirmation of the common positive enterovirus which is neither EV71nor CA16will play a significant role in prediction of HFMD epidemic,development of vaccineand the treatment of the disease.