急性弛缓性麻痹病例中 EV71感染情况及病毒特征分析

摘要

目的：分析近10年来福建省急性弛缓性麻痹（AFP）病例中EV71感染情况及病毒变异特征。方法应用描述流行病学分析AFP病例中EV71感染病例流行病学特征及临床表现特点，分析EV71病毒VP1区核苷酸与氨基酸同源性阐析病毒变异特征与趋势。结果根据EV71分离阳性数及 AFP病例报告率推算，2003-2012年6月福建省15岁以下儿童EV71相关AFP病例平均发病率为2．24/1000万，2008年以来呈上升趋势。AFP病例或其健康接触者分离的EV71病毒散在分布于9个设区市，以5-6月份多发，76．0％（19/25）为3岁以下儿童，男童为女童1．5倍。90．91％（20/22）的病例在麻痹前有发热，以单侧肢体麻痹（63．6％，14/22）为主，5例麻痹前有典型的手足口病表现，发病60d随访时2例仍残留麻痹。25例病毒株均属于C4基因型，除2003年分离毒株为C4b亚型外，其余均属于C4a亚型，2009-2011年病毒株间同源性高，与2008年安徽阜阳的代表株间同源性也较高，可能具有同一来源，并呈流行态势。结论利用完善的 A FP监测系统，分析EV71相关AFP病例发病情况及分离株病毒的特征可以从另一侧面反映EV71流行强度及趋势。%The prevalence of acute flaccid paralysis (AFP) associated with EV71 and the genetic variation in Fujian , China from 2003 to 2012 was investigated in this study .Descriptive epidemiology was used to analyze the epidemiologic and clinical features of AFP cases associated with EV 71 .Phylogenetic analysis was performed to explore the genetical characteris-tics of EV71 based on the complete VP1 nucleotide and amino acid sequences .Results showed that the mean incidence of EV71-associated AFP in children under 15 years old was 2 .24/10 000 000 in Fujian Province during 2003 and 2012 ,based on the number of EV71 isolates and the reported AFP cases .And the incidence has increased since 2008 .The EV71 strains isolated from the AFP cases or from the healthy contacts were distributed in 9 prefectures of Fujian Province ,most in the months of May and June .Of 76 .0% (19/25) of AFP cases associated with EV 71 were the children under 3 years and the male-to-female ratio was 1 .5 :1 .Twenty out of twenty-two cases (90 .91% ) had fevers before the onset of paralysis .Most cases had unilater-al limb paralysis (14/22 ,63 .6% ) .Typical manifestations of hand-foot-and-mouth disease (HFMD) were observed in five cases before the onset of paralysis .Residual paralysis was observed in two cases during the follow-up visits .The strains isolated from 25 cases belonged to genotype C4 .All other strains belonged to subtype C4a except the subtype C4b strains isolated in 2003 .The homology among the strains was high in 2009-2011 ,and the homology among these strains and the representative strains in Fuyang ,Anhui Province was also in the high level .Therefore ,it was possible that the isolated strains had the same origin and might cause the epidemic .In conclusion ,an AFP surveillance system could be developed for analyzing the incidence of AFP associated with EV71 ,determining the features of the isolates ,and describing the intensity and trends of EV71 epidem-ics .