Epidemiological and VP1 region genetic characteristics of coxsackievirus A6 in Xi′an city, 2021—2023
10.3760/cma.j.cn112309-20240619-00220
- VernacularTitle:2021—2023年西安市柯萨奇病毒A6型的流行及其VP1区的基因特征分析
- Author:
Zerun XUE
1
;
Rui WU
;
Hailong CHEN
;
Quanli DU
;
Yuewen HAN
;
Yujie YANG
;
Yangni DENG
;
Yao BAI
;
Baozhong CHEN
;
Xiaoli WEI
;
Haifei YOU
Author Information
1. 西安市疾病预防控制中心病毒科，西安 710054
- Publication Type:Journal Article
- Keywords:
Hand, foot and mouth disease;
Coxsackievirus A6;
Genetic characteristics
- From:
Chinese Journal of Microbiology and Immunology
2025;45(6):512-518
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the epidemiological and genetic characteristics of hand, foot and mouth disease (HFMD) caused by coxsackievirus A6 (CVA6) in Xi′an city from 2021 to 2023.Methods:Collected clinical cases of HFMD, epidemiological information and samples were obtained. The specimens were tested by the real-time RT-PCR for enterovirus A71(EVA71), CVA16, CVA6 and CVA10, respectively. The VP1 regions of CVA6 were amplified and sequenced, MEGA X was used for phylogenetic analysis.Results:From 2021 to 2023, a total of 1 393 HFMD samples were collected, 1 106 (79.40%, 1 106/1 393) of which were positive for enteroviruses. The proportions of EVA71, CVA16, CVA6 and CVA10 were 0.45% (5/1 106), 16.64% (184/1 106), 72.42% (801/1 106) and 2.17% (24/1 106). A total of 801 HFMD cases tested positive for CAV6, including 783 mild cases and 18 severe cases, mainly in children aged ≤5 years (86.02%, 689/801), with a male/female ratio of 1.49∶1. The composition ratio of CVA6 infection differed with year(χ 2=332.62, P<0.01), and the highest composition ratio of CVA6 was in 2023 (91.01%, 638/701). The nucleotide and amino acid similarities in the VP1 region of Xi′an strains of CVA6 were 92.4%-99.8% and 98.3%-100.0%, respectively. Compared with the CVA6 prototype strain(Gdula), the nucleotide and amino acid similarities in the VP1 region of Xi′an strains were 82.2%-84.0% and 95.4%-96.0%, respectively, and there were 18 amino acid mutations in different degrees. Based on the phylogenetic analysis of VP1 region sequences, the CVA6 strains in Xi′an city from 2021 to 2023 belonged to D3a subtype, and could be divided into two clusters with 18 strains in cluster 1 while two strain in cluster 2. Conclusions:The sub-genotype D3a of CVA6 is the predominant virus causing HFMD in Xi′an city from 2021 to 2023, and there are two transmission chains. The monitoring and prevention of CVA6 should be strengthened.
