Epidemiological And Etiological Characteristics Of Hand,Foot And Mouth Disease In Nanjing City Jiangsu Province In2010

Objective To analyze the epidemiological and etiological characteristics of Hand, Foot and Mouth disease (HFMD) in Nanjing in2010, find the epidemic rules and characteristics,and identify the pathogens of HFMD and study the genetic characterization of the main pathogen.Methods248throat swabs were collected from HFMD patients in Nanjing.Viral isolation was performed, and real-time PCR were performed with the positive isolates.20EV71strains from different types of cases were selected for entire VPl coding gene amplification and sequencing, finally phylogenetic tree was constructed among20EV71strains and EV71representative strains of known genotypes and subgenotypes.All CoxA16strains entire VP1coding region amplification and sequencing were then performed, finally phylognefic tree was constructed among Nanjing CoxA16strains and CoxA16representative strains of known genotypes and subgenotypes.Results Among the248throat swabs,148human enteroviruses were isolated, and among them,110EV71strains,28CoxA16strains, and8other enterovirus strains wre identified. the positive rate was44.35%,11.29%,3.23%, respectively. Then20EV71strains were performed by nucleotide sequencing. It showed that there was a little difference in the nucleotide and the amino acid among the20HEV71strains, the homology were95.51%～100%and98.32%-100%, respectively. The phylogenetic tree showed that20EV71strains were all belong to C4subgenotype.And28CoxA16positive isolates were performed by nucleotide sequencing. It showed that there was some difference in the nucleotide and the amino acid among the28CoxA16strains, the homology were90.01%～100%and97.98%-100%, respectively. The phylogenetic tree was constructed with28CoxA16strains and other strains represented all known genotype and subgenotype of CoxA16strains available from GeneBank, it revealed that the28CoxA16strains clustered within the B2evolution branch of B genotype. And there are several viral transmission chains.Conclusion EV71and CoxA16was the main pathogen of HFMD in Nanjing in2010. EV71and CoxA16isolated from patients with HFMD belongs to C4a and B2serotype, respectively. And EV71from different types of cases was not found significant difference in VP1region. And there are several transmission chains of CoxA16. CoxA16isolated from mixed infection cases and the separation of CoxA16alone did not find obvious difference in VP1region..Co-infection (EV71and CoxA16) does not appear to result in more sever clinical disease.