EV71 infection and viral features in patients with acute flaccid paralysis in Fujian,China,2003-2012 / 中国人兽共患病学报

ABSTRACT

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 .51 .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 .