Enterovirus 71 Infection In Children With Hand, Foot, And Mouth Disease In Shanghai, China:Epidemiology, Clinical Feature And Diagnosis

In 2012 a large outbreak of hand, foot, and mouth disease (HFMD) widely spread over China, causing more than 2 million HFMD cases and 567 deaths. Our objectives were to characterize the major pathogens responsible for this outbreak and to analyze the genetic characterization of the enterovirus 71 (EV71) strains; also, to analyze the dynamic patterns of neutralizing antibody (NAb) titer against EV71 and evaluate the diagnostic value of several methods for the detection of EV71 in clinical samples.We enrolled 396 inpatients with HFMD in Shanghai during the peak seasons from the end of March to the end of June. Clinical samples including stool, serum and blood and CSF were collected from patients 24 hours after hospitalization. Real-time RT-PCR and common RT-PCR were used for the detection of EV71 in clinical samples. VP1 gene of EV71 was analyzed through Phylogenetic analyses. Neutralization assay was performed to test the Nab titer against EV71. Anti-EV71 IgM was detected in the peripheral blood sample using EV71-IgM-Colloidal Gold immunochromatographic assay. According to the results, we concluded that EV71 C4 a remained the predominant subgenotype of EV71 strain circulating in Shanghai. The severity of the EV71 infecion may be associated with host factors but not virulence determinants in VP1. The blood EV71 IgM-Colloidal Gold assay can be a rapid bedside diagnostic tool used for the diagnosis of EV71 infection in severe HFMD.