Fakoorziba Mohammad Reza, Naddaf-Sani Ali Asghar, Moemenbellah-Fard Mohammad Djaefar, Azizi Kourosh, Ahmadnia Sara, Chinikar Sadegh
Department of Medical Entomology and Vector Control, Research Centre for Health Sciences, School of Health, Shiraz University of Medical Sciences, P.O. Box 71645-111, Shiraz, Iran,
Arch Virol. 2015 May;160(5):1197-209. doi: 10.1007/s00705-015-2379-1. Epub 2015 Mar 6.
Crimean-Congo haemorrhagic fever (CCHF) is a potentially fatal systemic viral disease in many parts of the world, including Iran. The nationwide incidence of human CCHF in endemic areas was 870 confirmed cases with 126 deaths (case fatality rate, CFR = 17.6 %) in the decade leading to 2012. The detection of the CCHF virus (CCHFV) genome in tick vectors is of fundamental importance for identifying these ticks as potential reservoirs of CCHFV infection. From May to October 2013, following detection of four new clinical cases resulting in two deaths in the city of Mashhad (northeast Iran), hard ticks were recovered from infested livestock in 40 villages in Khorasan-Razavi province and examined by the microscopic method for species identification. About a quarter of the ticks were then subjected to reverse-transcription polymerase chain reaction (RT-PCR) to detect the CCHFV genome. The PCR products were then sequenced, and their phylogenetic lineages were determined. A total of 407 hard ticks were captured, representing seven different species in two distinct genera. Members of the genus Hyalomma were widely distributed in all but two of the villages studied, and this was also the most frequent (83.3 %) tick genus. Of 105 adult ticks subjected to RT-PCR, four (3.8 %) ticks were found positive for the CCHFV genome. One brown ear tick, Rhipicephalus appendiculatus, was found to be naturally infected for the first time anywhere in the world. Ticks of Hyalomma asiaticum, Hyalomma marginatum, and Rhipicephalus turanicus were also found to be naturally infected with CCHFV. CCHFV found in these four different tick species were clustered in the same lineage with the Matin and SR3 strains from Pakistan and some other strains from Iran, indicating that these tick species were naturally infected with genetically closely related CCHFV in the region. The presence of CCHFV infection in four different hard tick species was confirmed using RT-PCR in northeast Iran. Part of this infection was attributed to Rh. appendiculatus, which is thus a potential new natural vector of CCHFV in Iran. It is also confirmed by phylogenetic analysis that CCHFV in this region is genetically closely related, even in the different tick species.
克里米亚-刚果出血热（CCHF）是一种在世界许多地区（包括伊朗）都可能致命的全身性病毒疾病。在2012年前的十年中，流行地区人类CCHF的全国发病率为870例确诊病例，其中126人死亡（病死率，CFR = 17.6%）。在蜱虫媒介中检测到CCHF病毒（CCHFV）基因组对于确定这些蜱虫为CCHFV感染的潜在宿主至关重要。2013年5月至10月，在伊朗东北部城市马什哈德检测到4例新临床病例并导致2人死亡后，从呼罗珊-拉扎维省40个村庄受感染的牲畜身上采集了硬蜱，并用显微镜方法进行物种鉴定。然后，约四分之一的蜱虫接受逆转录聚合酶链反应（RT-PCR）检测CCHFV基因组。对PCR产物进行测序，并确定其系统发育谱系。共捕获407只硬蜱，代表两个不同属的七个不同物种。璃眼蜱属的成员广泛分布在所研究的除两个村庄外的所有村庄，并且这也是最常见（83.3%）的蜱属。在接受RT-PCR检测的105只成年蜱中，有4只（3.8%）蜱的CCHFV基因组呈阳性。首次在世界任何地方发现一只棕色耳蜱（微小扇头蜱）自然感染。亚洲璃眼蜱、边缘璃眼蜱和图兰扇头蜱也被发现自然感染CCHFV。在这四种不同蜱种中发现的CCHFV与来自巴基斯坦的马丁株和SR3株以及来自伊朗的其他一些株聚集在同一谱系中，表明这些蜱种在该地区自然感染了基因密切相关的CCHFV。在伊朗东北部使用RT-PCR证实了四种不同硬蜱种中存在CCHFV感染。部分感染归因于微小扇头蜱，因此它是伊朗CCHFV潜在的新自然传播媒介。系统发育分析还证实，该地区的CCHFV即使在不同蜱种中基因也密切相关。
