BACKGROUND In recent years, Ecuador and other South American countries have experienced an increase in arboviral diseases. A rise in dengue infections was followed by introductions of chikungunya and Zika, two viruses never before seen in many of these areas. Furthermore, the latest socioeconomic and political instability in Venezuela and the mass migration of its population into the neighboring countries has given rise to concerns of infectious disease spillover and escalation of arboviral spread in the region. RESULTS We performed phylogeographic analyses of dengue (DENV) and chikungunya (CHIKV) virus genomes sampled from a surveillance site in Ecuador in 2014-2015, along with genomes from the surrounding countries. Our results revealed at least two introductions of DENV, in 2011 and late 2013, that initially originated from Venezuela and/or Colombia. The introductions were subsequent to increases in the influx of Venezuelan and Colombian citizens into Ecuador, which in 2013 were 343% and 214% higher than in 2009, respectively. However, we show that Venezuela has historically been an important source of DENV dispersal in this region, even before the massive exodus of its population, suggesting already established paths of viral distribution. Like DENV, CHIKV was introduced into Ecuador at multiple time points in 2013-2014, but unlike DENV, these introductions were associated with the Caribbean. Our findings indicated no direct CHIKV connection between Ecuador, Colombia, and Venezuela as of 2015, suggesting that CHIKV was, at this point, not following the paths of DENV spread. CONCLUSION Our results reveal that Ecuador is vulnerable to arbovirus import from many geographic locations, emphasizing the need of continued surveillance and more diversified prevention strategies. Importantly, increase in human movement along established paths of viral dissemination, combined with regional outbreaks and epidemics, may facilitate viral spread and lead to novel virus introductions. Thus, strengthening infectious disease surveillance and control along migration routes and improving access to healthcare for the vulnerable populations is of utmost importance.

中文翻译：

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从委内瑞拉和哥伦比亚的移民增加之后，厄瓜多尔的登革热和基孔肯雅病毒的起源。

背景技术近年来，厄瓜多尔和其他南美国家经历了虫媒病毒疾病的增加。登革热感染上升之后，出现了基孔肯雅热和寨卡病毒，这是许多地区从未发现的两种病毒。此外，委内瑞拉最新的社会经济和政治动荡及其人口向邻国的大规模迁移，引起了人们对传染性疾病外溢和在该地区的树状病毒传播升级的担忧。结果我们对2014-2015年在厄瓜多尔的一个监测点采样的登革热（DENV）和基孔肯雅热（CHIKV）病毒基因组以及周围国家的基因组进行了系统地理分析。我们的结果表明，在2011年和2013年末，至少有两次引入DENV，最初起源于委内瑞拉和/或哥伦比亚。引入委内瑞拉人和委内瑞拉公民进入厄瓜多尔的人数增加之后，2013年分别比2009年增加343％和214％。但是，我们表明，委内瑞拉在历史上一直是该地区DENV传播的重要来源，甚至在该国人口大量外流之前，这表明病毒传播的途径已经确定。与DENV一样，CHIKV在2013-2014年的多个时间点被引入厄瓜多尔，但与DENV不同，这些引入与加勒比海地区有关。我们的调查结果表明，截至2015年，厄瓜多尔，哥伦比亚和委内瑞拉之间没有直接的CHIKV联系，这表明，CHIKV目前并未遵循DENV传播的道路。结论我们的结果表明，厄瓜多尔很容易受到从许多地理位置进口的虫媒病毒的侵害，强调需要继续进行监测并采取更加多样化的预防策略。重要的是，人类沿着既定的病毒传播途径运动的增加，再加上区域性暴发和流行病，可能会促进病毒的传播并导致新型病毒的引入。因此，加强沿迁徙路线的传染病监测和控制以及改善弱势群体获得医疗保健的机会至关重要。可能促进病毒传播并导致新的病毒引入。因此，加强沿迁徙路线的传染病监测和控制以及改善弱势人群获得医疗保健的条件至关重要。可能促进病毒传播并导致新的病毒引入。因此，加强沿迁徙路线的传染病监测和控制以及改善弱势人群获得医疗保健的条件至关重要。