Sherifi Kurtesh, Cadar Daniel, Muji Skender, Robaj Avni, Ahmeti Salih, Jakupi Xhevat, Emmerich Petra, Krüger Andreas
Faculty of Agricultural and Veterinary Medicine, University of "Hasan Prishtina", Prishtina, Kosovo.
Department of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
PLoS Negl Trop Dis. 2014 Sep 25;8(9):e3168. doi: 10.1371/journal.pntd.0003168. eCollection 2014 Sep.
Despite being a small country, Kosovo represents one of the few foci of Crimean-Congo hemorrhagic fever (CCHF) in Europe. The distribution of Kosovar tick vectors and the evolution of CCHF virus in ticks are both as yet unknown. A better description of the extent and the genetic diversity of CCHFV in ticks from endemic settings is essential, in order to be controlled. We investigated the 2012 distribution of Kosovar ticks alongside the prevalence and the phylogeography of tick-derived CCHFV. Hyalomma marginatum dominated in the endemic municipalities with 90.2% versus 24.3% in the non-endemic regions. Of 1,102 tested ticks, 40 (3.6%) were CCHFV-positive, belonging to H. marginatum (29), Rhipicephalus bursa (10), and Ixodes ricinus (1). The virus strains clustered with clade V and VI related sequences. They fell into two lineages: Kosovo I and II. Kosovo I comprised strains recovered exclusively from R. bursa ticks and was closely related to AP92 prototype strain. Kosovo II clustered into Kosovo IIa, including human-derived strains, and IIb including only strains detected in H. marginatum and I. ricinus. Our phylogeographic reconstruction suggests two temporally distinct CCHFV introductions: the most probable location of the most recent common ancestor of Kosovo I lineage was in Greece (63 years ago) and that of lineages IIa-b in Turkey (35 years ago). After each CCHFV introduction into Kosovo, subsequent lineage expansions suggest periods of in situ evolution. The study provides the first insight into the genetic variability and the origin of CCHFV in ticks from Kosovo. Our findings indicate the spreading of CCHFV to non-endemic areas, which underlines the importance of further studies in order to monitor and predict future CCHF outbreaks in Kosovo. The AP92-like strains appear to be more widespread than previously thought and may provide a promising target for experimental studies due to their assumed low pathogenicity.
尽管科索沃是一个小国，但它是欧洲为数不多的克里米亚-刚果出血热（CCHF）疫源地之一。科索沃蜱传病媒的分布以及蜱中CCHF病毒的演变目前均不清楚。为了对该病进行控制，更好地描述来自流行地区蜱中CCHFV的范围和遗传多样性至关重要。我们调查了2012年科索沃蜱的分布以及蜱源性CCHFV的流行情况和系统地理学。边缘璃眼蜱在流行市占主导地位，占90.2%，而非流行地区为24.3%。在1102只检测的蜱中，40只（3.6%）CCHFV呈阳性，分别属于边缘璃眼蜱（29只）、柏氏扇头蜱（10只）和蓖麻硬蜱（1只）。病毒株与V和VI分支相关序列聚类。它们分为两个谱系：科索沃I和II。科索沃I包括仅从柏氏扇头蜱中分离出的毒株，与AP92原型毒株密切相关。科索沃II聚类为科索沃IIa，包括人源毒株，以及IIb，仅包括在边缘璃眼蜱和蓖麻硬蜱中检测到的毒株。我们的系统地理学重建表明CCHFV有两次时间上不同的引入：科索沃I谱系最近共同祖先最可能的位置在希腊（63年前），而IIa - b谱系在土耳其（35年前）。每次CCHFV引入科索沃后，随后的谱系扩张表明有原地进化期。该研究首次深入了解了科索沃蜱中CCHFV的遗传变异性和起源。我们的研究结果表明CCHFV正在向非流行地区传播，这凸显了进一步研究以监测和预测科索沃未来CCHF疫情爆发的重要性。AP92样毒株似乎比以前认为的分布更广，由于其假定的低致病性，可能为实验研究提供一个有前景的靶点。
