Faculty of Public Health, Thammasat University (Rangsit Center), Khlong Luang, Pathum Thani 12121, Thailand.
Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok-noi, Bangkok 10700, Thailand.
Int J Infect Dis. 2019 Mar;80:84-91. doi: 10.1016/j.ijid.2018.12.020. Epub 2019 Jan 11.
Enterovirus A71 (EV-A71) and coxsackievirus A16 (CV-A16) are the major causative agents of hand, foot and mouth disease (HFMD) worldwide, particularly in the Asia-Pacific region. Several strains have emerged, circulated, and faded out over time in recent decades. This study investigated the EV-A71 and CV-A16 circulating strains and replacement of genotypes/subgenotypes in Thailand during the years 2000-2017.
The complete VP1 regions of 92 enteroviruses obtained from 90 HFMD patients, one asymptomatic adult contact case, and one encephalitic case were sequenced and investigated for serotypes, genotypes, and subgenotypes using a phylogenetic analysis.
The 92 enterovirus isolates were identified as 67 (72.8%) EV-A71 strains comprising subgenotypes B4, B5, C1, C2, C4a, C4b and C5, and 25 (27.2%) CV-A16 strains comprising subgenotypes B1a and B1b. Genotypic/subgenotypic replacements were evidenced during the study period. EV-A71 B5 and C4a have been the major circulating strains in Thailand for more than a decade, and CV-A16 B1a has been circulating for almost two decades.
This study provides chronological data on the molecular epidemiology of EV-A71 and CV-A16 subgenotypes in Thailand. Subgenotypic replacement frequently occurred with EV-A71, but not CV-A16. Monitoring for viral genetic and subgenotypic changes is important for molecular diagnosis, vaccine selection, and vaccine development.
肠道病毒 A71 型（EV-A71）和柯萨奇病毒 A16 型（CV-A16）是全球手足口病（HFMD）的主要病原体，尤其是在亚太地区。近几十年来，已有多种毒株出现、传播和消失。本研究调查了 2000 年至 2017 年期间泰国流行的 EV-A71 和 CV-A16 循环株及基因型/亚基因型的替换情况。
从 90 例 HFMD 患者、1 例无症状成人接触者和 1 例脑炎病例中获得 92 株肠道病毒，对其完整 VP1 区进行测序，并通过系统进化分析对血清型、基因型和亚基因型进行分析。
92 株肠道病毒分离株鉴定为 67 株（72.8%）EV-A71 株，包括亚基因型 B4、B5、C1、C2、C4a、C4b 和 C5，以及 25 株（27.2%）CV-A16 株，包括亚基因型 B1a 和 B1b。研究期间证实了基因型/亚基因型的替换。EV-A71 B5 和 C4a 已在泰国流行超过 10 年，CV-A16 B1a 已流行近 20 年。
本研究提供了泰国 EV-A71 和 CV-A16 亚基因型分子流行病学的时间序列数据。EV-A71 经常发生亚基因型替换，但 CV-A16 则不然。监测病毒遗传和亚基因型的变化对于分子诊断、疫苗选择和疫苗开发非常重要。
