Pathogen spectrum of hand,foot and mouth disease and genetic characteristics of VP1 of coxsackievirus A6 and A10 in some areas of Hubei,2016

Objective To understand the characteristics of pathogen spectrum of hand foot and mouth disease (HFMD) in some areas of Hubei province in 2016 and analyze the genetic characteristics of coxsackievirus A6 and A10.Methods Blood samples were collected from HFMD cases in some areas in Hubei in 2016 for the viral nucleic acid extraction.The full-length VP1 gene of viral RNA was amplified with one-step reverse transcription polymerase chain reaction (RT-PCR) and sequenced.The viral genotypes were identified by the Blast.The homology and phylogenetic analyses of VP1 gene of Cox A6 and Cox A10 were conducted.Results Based on the statistics of etiology surveillance on HFMD in some areas of Hubei in 2016,the positive rates of EV71,Cox A16 and other enteroviruses was 29.4%(599/2 035),25.7%(522/2 035) and 44.9%(914/2 035),respectively.The positive rate of Cox A6 and Cox A10 was 56.6%(47/83) and 22.9%(19/83) respectively in 83 positive samples of non EV71 and non Cox A16.The other enteroviruses detected included Cox A2(2 strains),Cox A4(7 strains),CB4(2 strains),CB5(2 strains),CB6(1 strain),Echo5(1 strain),Echo9(1 strain) and Echo25(1 strain).The 22 strains of Cox A6 shared 95.1%-100.0% nucleotide homology and 11 strains of Cox A10 shared 95.2%-100.0% nucleotide homology respectively.Cox A6 and Cox A10 viruses detected in both China and other countries could be divided into eight (A-H) and seven (A-G) genetic lineages,respectively.Cox A6 viruses detected Hubei and other areas of China were in H lineage.Cox A10 viruses detected in Hubei and other areas of China were in G lineage.Conclusion In addition to EV71 and Cox A16 which were predominant,Cox A6,Cox A10 and other enteroviruses were detected in some areas of Hubei in 2016.Among other enteroviruses,Cox A6 was the main pathogen,followed by Cox A10.It is necessary to strengthen the surveillance for other enteroviruses and related molecular characteristics analysis.