Pathogens and their genetic characteristics of hand-foot-mouth disease in Tianjin city,2013

Objective To reveal the pathogen spectrum and its genetic characteristics of hand-foot-mouth disease(HFMD)isolated from Tianjin city in 2013.Methods Specimens of HFMD cases were detected with real time reverse transcription(RT)-PCR.Virus strains were isolated from some positive specimens with human rhabdomyosarcoma(RD)cells.The complete VP1 coding gene from isolated strains was sequenced and analyzed.Results For the 1728 specimens from HFMD cases,the overall positive rate of enterovirus was 80.44%(1390/1728);the positive rates of enterovirus 71(EV71),coxsackievirus A16(CVA16),coxsackievirus A6(CVA6),coxsackievirus A10(CVA10),and other enterovirus(EV)were 16.38%,11.46%,43.92%,1.56%,and 7.12%,respectively.All the strains were classified into 12 genotypes and belonged to human enterovirus A(HEV-A)and human enterovirus B(HEV-B).Phylogenetic analysis showed that the genetic traits of the strains isolated in Tianjin were close to those of the strains isolated in China or neighboring countries.Conclusion The spectrum of pathogens causing HFMD epidemics in Tianjin city in 2013 is multifarious and CVA6 is the prevalent pathogen.