2020—2022年陕西省手足口病病原的监测及主要型别的流行特征分析

Pathogenic Surveillance of HFMD and molecular epidemic characteristics of major epidemic types in Shaanxi province,China,from 2020 to 2022

目的 了解2020—2022年陕西省手足口病主要病原构成情况和流行规律。方法 收集陕西省各省辖市手足口监测病例的核酸检测结果和病例资料,分离肠道病毒核酸检测阳性样本,并对流行优势病原的肠道病毒VP1区进行PCR扩增、序列测定和毒株基因亚型鉴定。结果 2020—2022年陕西省共采集6 352例手足口病例样本,肠道病毒核酸检测阳性4 417例(69.54%)。2020年和2021年,以除外EV-A71和EV-A16的其他肠道病毒为主要流行型别,构成比分别为95.43%和74.35%;2022年,以CV-A16型为主要流行型别,构成比52.88%。对8个省辖市4 145例手足口实验室确诊病例开展其他肠道病毒中CV-A6型和CV-A10型检测,2020年—2022年CV-A6型在其他肠道病毒的占比分别是75.31%、62.56%和61.15%,是陕西省其他肠道病毒中的优势流行型别。2020—2022年陕西省分离测序毒株239株,CV-A16型151株,CV-A6型72株,CV-A10型6株,CV-A4型2株,CV-B3型8株。CV-A16型和CV-A6型是主要流行型别,经系统进化分析,CV-A6型以D3亚型为主要流行亚型,CV-A16型以B1a和B1b共存,2021年和2022年B1a亚型占比逐年升高,并取代B1b成为主要流行亚型。结论 2020—2022年陕西省手足口病较往年处于低流行水平,主要病原以其他肠道病毒、CVA16交替出现。

Objective To investigate the composition and prevalence of hand-foot-mouth disease(HFMD)in Shaanxi province from 2020 to 2022.Methods Nucleic acid detection results and case data of HFMD surveillance cases in cities of Shaanxi province were collected.Positive samples of enterovirus nucleic acid detection were isolated.PCR amplification,sequence determination and gene subtype identification of enterovirus VP1 region of epidemic dominant pathogen were performed.Results From 2020 to 2022,a total of 6352 samples of HFMD cases were collected in Shaanxi province,and 4417 samples tested positive for enterovirus nucleic acid,with a positive rate of 69.54%.In 2020 and 2021,other enteroviruses excluding EV-A71 and EV-A16 were the main epidemic types,with a composition ratio of 95.43%and 74.35%,respectively.In 2022,CV-A16 was the main epidemic type,with a composition ratio of 52.88%.CV-A6 and CV-A10 types of other enteroviruses were detected in 4145 laboratory confirmed cases of HFMD in 8 cities.CV-A6 accounted for 75.31%,62.56%and 61.15%of other enteroviruses,which was the dominant epidemic type of other enteroviruses in Shaanxi province.From 2020 to 2022,239 isolates,151 CV-A16 isolates,72 CV-A6 isolates,6 CV-A10 isolates,2 CV-A4 isolates and 8 CV-B3 isolates were sequenced in Shaanxi province.CV-A16 and CV-A6 were the main epidemic types.According to phylogenetic analysis,the D3 subtype was the main epidemic subtype of CV-A6,while B1a and B1b coexisted for CV-A16.The proportion of B1a subtype increased year by year in 2021 and 2022,and it replaced B1b as the main epidemic subtype.Conclusion From 2020 to 2022,the prevalence of HFMD in Shaanxi province is at a lower level than that in previous years,and the main pathogens are other enteroviruses and CVA16.