Genetic characteristics of enterovirus 71 in 2008 in Xi'an.

Objective To study the aetiological agent of hand-foot-mouth disease, and the genetic characteristic of EV71 of Xi'an in 2008. Mehtods 124 bleb fluid, pharynx swab and stool samples of hand-foot-mouth disease were collected from several hospitals in Xi'an in 2008, and all of them were tested by RTPCR assay with one general primer pair for enterovirus and two specific primer pairs for enterovirus 71 and Coxsackie virus A16. Some EV71positive samples were used to isolate the virus, and 7 EV71 strains' VP1 were sequenced and phyletic evolution was analysed. Results The results showed that in 91 enterovirus positive samples, enterovirus 71 accounted for 30. 76% , and CA16 for 49.45% , and the VP1 of 7 viruses all belonged to subtype C4. Conclusions In 2008, the main aetiological agent causing HFMD in Xi'an was CA16 and the EV71 ciuculating in Xi'an in 2008 had close relation with the EV71 circulating in the other areas in the mainland of China. Key words: Hand, foot and mouth disease;  Enterovirus;  Phylogeny;  Vival structural proteins