Lindh Erika, Argentini Claudio, Remoli Maria Elena, Fortuna Claudia, Faggioni Giovanni, Benedetti Eleonora, Amendola Antonello, Marsili Giulia, Lista Florigio, Rezza Giovanni, Venturi Giulietta
Department of Infectious Disease, Istituto Superiore di Sanità, Rome, Italy.
European Program for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
Open Forum Infect Dis. 2018 Dec 12;6(1):ofy321. doi: 10.1093/ofid/ofy321. eCollection 2019 Jan.
Chikungunya virus is an emerging mosquito-borne pathogen with a wide global distribution. With the severe morbidity that it causes, chikungunya virus is a major public health problem in the affected areas and poses a considerable risk for unaffected areas hosting competent vector populations. In the summer of 2017, Italy experienced a chikungunya virus outbreak that spread in the Lazio region and caused a secondary outbreak in the Calabrian village of Guardavalle, with a final case number of 436. The causative strain was recognized as an Indian Ocean lineage (IOL) virus.
To understand the underlying genetic and molecular features of the outbreak virus, viruses from mosquito pools and clinical samples were isolated in cell culture and subjected to whole-genome sequencing and genetic analyses.
All 8 characterized genomes shared a high sequence identity. A distinct substitution pattern in the Italian 2017 viruses (including mutations in E1, E2, and nsP4) was partly shared with the Pakistani 2016 outbreak viruses. Evolutionary analyses indicate that these 2 recent outbreaks and several geographically widely distributed, travel-associated viruses form a cluster of rapidly emerging Indian-origin IOL viruses.
Our analyses show that the 2017 Italian outbreak virus belongs to a cluster of novel IOL chikungunya viruses originating in India. Their emergence calls for enhanced monitoring and strengthened preparedness measures, including vector control programs and raised awareness among general practitioners in countries potentially at risk.
基孔肯雅病毒是一种新出现的蚊媒病原体，在全球广泛分布。由于它会导致严重发病，基孔肯雅病毒是受影响地区的一个主要公共卫生问题，对拥有适宜病媒种群的未受影响地区也构成相当大的风险。2017年夏天，意大利经历了一次基孔肯雅病毒疫情，疫情在拉齐奥地区蔓延，并在卡拉布里亚的瓜尔达瓦莱村引发了二次疫情，最终病例数为436例。致病毒株被认定为印度洋谱系（IOL）病毒。
为了解疫情病毒的潜在遗传和分子特征，从蚊群和临床样本中分离出病毒，在细胞培养中进行全基因组测序和遗传分析。
所有8个已鉴定的基因组具有高度的序列同一性。2017年意大利病毒（包括E1、E2和nsP4中的突变）的独特替代模式与2016年巴基斯坦疫情病毒部分相同。进化分析表明，这两次近期疫情以及几种地理分布广泛、与旅行相关的病毒形成了一组迅速出现的源自印度的IOL病毒。
我们的分析表明，2017年意大利疫情病毒属于源自印度的新型IOL基孔肯雅病毒群。它们的出现需要加强监测和强化防范措施，包括病媒控制计划以及提高潜在风险国家全科医生的认识。
