Chikungunya virus (CHIKV) is a mosquito-borne emerging pathogen that is transmitted to humans through the bite of female Aedes mosquitoes. CHIKV infection has become a major public health concern worldwide, as it has a significant impact on the healthcare system. Since 2004, the virus has emerged in Africa and subsequently spread to countries located near the Indian Ocean, including India, and to Europe, the Americas, and Asia. In Thailand, a large CHIKV outbreak occurred during 2008-2009 and was caused by a virus originating from the east/central/south African (ECSA) CHIKV genotype. Since then, the ECSA genotype of CHIKV has continued to circulate and has caused sporadic cases in different areas in Thailand. Approximately 20,000 reported cases have been confirmed by the Bureau of Epidemiology, Ministry of Public Health, Thailand, from January 1, 2018 to July 31, 2020. However, the causes of this CHIKV re-emergence remain unclear. To obtain a better understanding of CHIKV circulation during the recent outbreak in Bangkok, Thailand, complete genome analysis of CHIKV isolates from field-caught mosquitoes collected in outbreak areas was performed. A total of 28 Ae. aegypti samples (21 females and 7 males) were collected, and individual mosquitoes were used for CHIKV detection and isolation. Eleven of 28 (39.29%) female and three of 28 (10.71%) male mosquitoes were positive for CHIKV by E1 nested RT-PCR. Four CHIKV isolates were successfully isolated from four female Ae. aegypti mosquitoes. Based on complete genome analysis, several amino acid substitutions were identified in the protein coding region. The E1:K211E and E2:V264A mutations in the background of the E1:226A mutation were observed in all four CHIKV isolates. An important observation was the presence of one amino acid substitution, leading to an E1:K245R change. This mutation was found in all four CHIKV isolates from mosquitoes in this study and in Thai patients described previously. Additionally, phylogenetic analysis indicated that the four CHIKV isolates belonged to the Indian Ocean clade of the ECSA genotype. The results obtained in this study provide detailed information on the molecular characteristics and evolution of currently circulating CHIKV strains in Thailand, which are useful for developing prevention and control strategies.

中文翻译：

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从最近在泰国曼谷爆发的埃及伊蚊中分离出的基孔肯雅病毒的遗传特征。

基孔肯雅病毒 (CHIKV) 是一种由蚊子传播的新兴病原体，通过雌性伊蚊的叮咬传播给人类。CHIKV 感染已成为全球主要的公共卫生问题，因为它对医疗保健系统产生重大影响。自 2004 年以来，该病毒在非洲出现，随后传播到印度洋附近的国家，包括印度，以及欧洲、美洲和亚洲。在泰国，2008 年至 2009 年期间发生了大规模 CHIKV 疫情，由源自东/中/南非 (ECSA) CHIKV 基因型的病毒引起。此后，CHIKV的ECSA基因型持续传播，并在泰国不同地区造成散发病例。从 1 月 1 日起，泰国公共卫生部流行病学局已确认约 20,000 例报告病例，2018 年至 2020 年 7 月 31 日。然而，这次 CHIKV 重新出现的原因仍不清楚。为了更好地了解泰国曼谷最近爆发的 CHIKV 传播，对在爆发地区收集的野外捕获的蚊子进行了 CHIKV 分离株的完整基因组分析。共 28 个 Ae。收集埃及伊蚊样本（21 只雌性和 7 只雄性），并使用个体蚊子进行 CHIKV 检测和隔离。28 只 (39.29%) 雌性蚊子中有 11 只 (39.29%) 和 28 只 (10.71%) 雄性蚊子中的 3 只通过 E1 巢式 RT-PCR 对 CHIKV 呈阳性。从四个雌性 Ae 中成功分离出四个 CHIKV 分离株。埃及蚊子。基于完整的基因组分析，在蛋白质编码区鉴定了几个氨基酸取代。E1 背景中的 E1:K211E 和 E2:V264A 突变：在所有四种 CHIKV 分离株中均观察到 226A 突变。一个重要的观察是存在一个氨基酸取代，导致 E1:K245R 变化。在这项研究中从蚊子中分离出的所有四种 CHIKV 分离株和之前描述的泰国患者中都发现了这种突变。此外，系统发育分析表明，四个 CHIKV 分离株属于 ECSA 基因型的印度洋进化枝。本研究获得的结果提供了有关泰国目前流行的 CHIKV 毒株的分子特征和进化的详细信息，这有助于制定预防和控制策略。在这项研究中从蚊子中分离出的所有四种 CHIKV 分离株和之前描述的泰国患者中都发现了这种突变。此外，系统发育分析表明，四个 CHIKV 分离株属于 ECSA 基因型的印度洋进化枝。本研究获得的结果提供了有关泰国目前流行的 CHIKV 毒株的分子特征和进化的详细信息，这有助于制定预防和控制策略。在这项研究中从蚊子中分离出的所有四种 CHIKV 分离株和之前描述的泰国患者中都发现了这种突变。此外，系统发育分析表明，四个 CHIKV 分离株属于 ECSA 基因型的印度洋进化枝。本研究获得的结果提供了有关泰国目前流行的 CHIKV 毒株的分子特征和进化的详细信息，这有助于制定预防和控制策略。