2019年云南省德宏州手足口病的病原构成及柯萨奇病毒A组16型基因特征分析

Pathogen spectrum of hand, foot and mouth disease and the genetic characterization of coxsackievirus A16 in Dehong prefecture of Yunnan province of China in 2019

目的对2019年云南省德宏州手足口病的病原构成及柯萨奇病毒A16型(coxsackievirus A16,CV-A16)的基因特征进行分析。方法对2019年云南省德宏州的650份手足口病患者的粪便标本进行病毒分离,对分离到的肠道病毒(enterovirus, EV)毒株进行VP1区基因测序定型并对CV-A16的基因特征进行分析。结果 2019年云南省德宏州分离到63株EV毒株,EV分离率为9.69%(63/650),均为肠道病毒A组病毒(enterovirus species A,EV-A)。EV-A组病毒中,CV-A16毒株最多(80.95%,51/63)。基因进化分析表明,51株CV-A16毒株均为B1基因亚型(subgenotype B1),并分为2个不同的进化分支(B1a和B1b),其中11.76%(6/51)为B1a, 88.24%(45/51)为B1b。结论 2019年德宏州发生了以CV-A16为主的手足口病暴发。CV-A16的B1a和B1b两个分支同时在德宏州流行,但以B1b分支为主。

Objective To study the enterovirus(EV) epidemic patterns among hand, foot and mouth disease(HFMD) patients and analyze the genetic characteristics of coxsackievirus A16(CV-A16) isolated from Dehong prefecture of Yunnan province of China in 2019. Methods Virus isolation was performed from 650 stool samples of HFMD patients in Dehong prefecture in 2019 and the VP1 gene of the 63 positive EVs was amplified and sequenced to analyze the genetic characteristics of CV-A16. Results A total of 63 strains of EVs were isolated from 650 stool samples with an isolation rate of 9.69%(63/650), all these strains were enterovirus species A(EV-A) while no EV-B, EV-C and EV-D strains were identified.Among EV-A viruses, CV-A16 was mostly isolated, accounting for 80.95%(51/63).The genetic characteristics analysis showed that all 51 strains of CV-A16 belonged to sub genotype B1 which were further divided into 2 subgenotypes(B1 a and B1 b), among which, 6 strains were B1 a cluster, accounting for 11.76%(6/51);45 strains were B1 b cluster, accounting for 88.24%(45/51). Conclusions CV-A16 caused HFMD outbreak was occurred in Dehong prefecture of Yunnan province in 2019.Two clusters(B1 a and B1 b) of CV-A16 co-circulated in Dehong prefecture in 2019, B1 b cluster being the predominant one.