Epidemiology and genetic characteristics of EV71 in Fujian Province,China / 中国人兽共患病学报

ABSTRACT

For investigating the epidemiology and genetic characteristics of enterovirus 71 (EV71) in Fujian from 2010 to 2015,we analyzed the surveillance data of EV71 and sequenced VP1 genes of 72 EV71 strains randomly picked from the past 6 years.The overall infection rate was gradually down and one incidence peak (from May to July) was observed each year.Major infectious population were focused on Xiamen,Fuzhou,Nanping and Quanzhou,the ages ranged from one to three years old.Scattered children were the most infected ones.The proportion of EV71 in the severe case was higher than in the HMFD(χ2 =732.064 5,P＜0.000 1).EV71 circulated from 2010 to 2015 in Fujian Province was belonged to subgenotype C4a in consistent with vaccine strain (H07).Compared with the VP1 of vaccine strains,the divergence of complete VP1 nucleotide sequence was gradually expanding as time distance increased,but the sequence of amino acid was not found obvious difference.Variations in 4 key immune epitopes of amino acid had not appeared a regular pattern in year and not consistent with the trend of proportion of EV71 in HMFD.As a result,we considered the epidemiology characteristics of EV71 in Fujian was obvious,72 strains still belonged to C4a subgenotype and had no outstanding antigenic drift or mutation.Extensive epidemiology surveillance and genetic characteristic are needed for the application of EV71 vaccine.