2009-2017年江苏省手足口病病原谱及柯萨奇A16型的分子流行病学研究

目的描述2009-2017年江苏省手足口病(HFMD)病原谱及柯萨奇A16型(CVA16)的流行病学、基因变异及遗传进化特征。方法对2009-2017年江苏省手足口病发病资料和病原学检测情况进行统计分析,选取120株CVA16病毒分离株进行VP1区全长基因序列测定,并对核苷酸及氨基酸序列进行同源性比较及系统进化分析。结果 2009-2017年江苏省共报告手足口病1 013 771例。其中,手足口病肠道病毒阳性病例37 389例,主要病原构成为EV71(39.85%)和CVA16(30.13%);重症病例中,以EV71为主要病原,CVA16及其他肠道病毒引起的重症病例较少。CVA16在每年的3～7月和9～11月出现流行高峰,主要感染1～4岁年龄段儿童,男性比例高于女性。江苏省地区流行的CVA16毒株属于B1a亚型和B1b亚型,其中B1b亚型为优势流行基因亚型。120株CVA16病毒分离株VP1区核苷酸及编码氨基酸序列同源性分别为87.5%～100%、97%～100%。结论 2009-2017年,江苏省地区流行的CVA16具有明显的时间、人群分布特征;120株CVA16分离株属于B1a亚型和B1b亚型。CVA16分离株核苷酸序列变异较大,但氨基酸同源性较高,推断存在一定的同义突变。

Pathogen spectrum of hand,foot and mouth disease and molecular epidemiology of coxsackievirus A16 strains in Jiangsu province,China, 2009-2017

To analyze the pathogen spectrum of hand, foot, and mouth disease (HFMD) and to investigate the molecular epidemiology, genetic variation and evolution of coxsackievirus A16 (CVA16) strains were analyze for the data on epidemiological characteristics and pathogens detected results of HFMD cases in Jiangsu province from 2009 to 2017. The complete VP1 sequences of 120 CVA16 strains were amplified and sequenced for the homological and phylogenetic analysis. Results showed that a total of 1 013 771 suspected HFMD patients were reported in Jiangsu province from 2009 to 2017, and the positive enterovirus samples were 37 389. EV71 (30.13%) and CVA16 (30.13%) were the predominant pathogens among these cases. The major severe cases were EV71. The CVA16 infection showed two peaks during April-July and September-November. The major CVA16 infectious population was focused on the ages ranged from one to four years old with higher incidence in males than in females. The 120 CVA16 strains were divided into subgenotype of B1a and B1b, and the B1b subgenotype was the predominant genotype of Jiangsu CVA16 strains. The nucleotide and amino acid identity among the CVA16 strains were 87.5%~100% and 97%~100%, respectively. Results indicate that epidemiology characteristics of CVA16 in Jiangsu is significant, 120 strains belong to B1a and B1b subgenotype, and they are random nucleotide sequences of CVA16 isolates are varied greatly, but the homology only distributed in mild cases and severe cases based on phylogenetic tree analysis. The amino acid is comparatively high. Thus, it is indicated the existence of some synonymous mutations.