病毒学报

为了研究新余地区手足口病(Hand foot and mouth disease,HFMD)的流行特征和优势株的分子特征，掌握HFMD在新余地区的流行趋势及变迁规律。收集2018-2023年新余地区疑似HFMD咽拭子标本476份，应用实时荧光定量PCR(RT-PCR)进行核酸检测，分析病原体类型和流行情况，挑选22株柯萨奇病毒A组6型(Coxsackievirus A6,CVA6)病原体样本进行VP1基因扩增，用Blast进行序列比对分析，用MEGA 11构建系统发育树。新余地区2018-2023年HFMD阳性检出率为36.97%，其中优势型别CVA6的阳性检出率为31.72%，占阳性总数的85.80%。2019年和2022年HFMD阳性率较低，与2023年差异具有统计学意义(χ²=33.000,P<0.05)，其他年度之间无差异。2018-2023年HFMD具有季节性，除2020年外，发病高峰均集中在4～6月份，易感年龄是5岁以下，男女易感性无差别。2019-2021年90%以上的HFMD阳性病例为CVA6型，2022-2023年均为CVA6型，2018年为柯萨奇病毒A组16型(Coxsackievirus A16,CVA16)和CVA6型交叉流行，未发现其它型别。22株CVA6均属于D3基因亚型，它们的VP1基因核苷酸和氨基酸相似性比较高，分别为91.91%～100%和92.88%～100%，但发现39个(12.70%,39/307)氨基酸变异。2019-2023年新余地区HFMD的绝对优势病原体为CVA6型，发病具有明显的季节性和人群特征，春夏之交应加强5岁以下儿童的HFMD防控。22株CVA6均为D3亚型，不同年份间形成多个小分支，表明新余地区CVA6存在VP1基因多样性的进化趋势，应进一步加强新余地区优势病原体CVA6流性特征及分子特征分析。本研究可为制定新余地区手足口病防控策略和疫苗研究提供依据。

This study aim to analyze the epidemiological characteristics of hand-foot-and-mouth disease(HFMD)and the molecular features of the predominant strain in Xinyu,China from 2018 to 2023,providing a foundation for future prevention,control strategies,and vaccine research.A total of 476 suspected HFMD throat swab specimens were collected in Xinyu,China from 2018 to 2023.Real-time quantitative PCR (RT-q PCR) was used for nucleic acid detection to determine pathogen types and epidemic patterns.Twenty-two Coxsackievirus A6 (CVA6) samples were selected for VP1 gene amplification.Sequence alignment was performed using BLAST,and a phylogenetic tree was constructed using MEGA 11.The overall HFMD positivity rate in Xinyu,China from 2018 to 2023 was 36.97%,with CVA6 being the predominant genotype,accounting for 31.72%of all tested samples and 85.80%of positive cases.The HFMD positivity rates in 2019and 2022 were significantly lower compared to 2023(χ²=33.000,P<0.05),while no statistically significant differences were observed among other years.HFMD exhibited clear seasonality,with incidence peaking between April and June in most years except 2020.The most susceptible age group was children under five years old,with no significant difference in susceptibility between genders.From 2019 to 2021,over 90%of HFMD-positive cases were attributed to CVA6,and from 2022 to 2023,all detected cases were CVA6.In2018,both CVA16 and CVA6 co-circulated,with no other serotypes detected.Phylogenetic analysis revealed that all 22 CVA6 strains belonged to the D3 genetic sublineage.The VP1 gene sequences exhibited high nucleotide and amino acid similarity,ranging from 91.91%to 100%and 92.88%to 100%,respectively.However,39 amino acid mutations (12.70%,39/307) were identified.CVA6 was the predominant HFMD pathogen in Xinyu,China from 2019 to 2023.The disease demonstrated distinct seasonal and demographic patterns,emphasizing the need for strengthened HFMD prevention and control measures,particularly for children under five years old during the spring-summer transition.All 22 CVA6 strains belonged to the D3sublineage,with multiple small phylogenetic branches emerging over different years,indicating an evolutionary trend toward VP1 gene diversity in Xinyu,China.Further epidemiological and molecular characterization of CVA6 is essential for understanding its transmission dynamics and genetic evolution.This study provides a scientific basis for the development of HFMD prevention strategies and vaccine research in Xinyu,China.