Detection and subtype analysis of VP1 gene of enterovirus 71 strains isolated from children with hand,foot and mouth disease in Shanghai area during the first half year of 2009 / 中华传染病杂志

ABSTRACT

Objective To understand the characteristics of molecular epidemiology of enterovirus 71(EV71) in children with hand, foot and mouth disease (HFMD) in Shanghai area during the first half year of 2009. Methods Seventy-three throat swabs and 38 stool samples were collected from 95 hospitalized children with clinical diagnosis of HFMD in Children's Hospital of Fudan University during April to May 2009. TaqMan real-time reverse transcription-polymerase chain reaction (RT-PCR) and nest RT-PCR were used to detect EV71 VP1, followed by gene sequencing analysis. Results Six of the 73 throat swabs were EV71 positive with the detection rate of 8.2%. In the 38 stool samples, 24 were EV71 positive with the detection rate of 63.2%. Twenty-eight nested RT-PCR positive samples were sequenced and the genetic analysis showed that 27 were C4 subtype,which were absolute dominant strain and the other one was C2 subtype. The isolated strain from a fatal case was C4 subtype and there was no obvious mutation found in VP1 region. Conclusions EV71 is an important pathogen in HFMD children in Shanghai area during April to May 2009. C4 subtype strains are absolutely dominant, and accompanied by epidemic strains of subtype C2.