Dengue virus surveillance in Singapore reveals high viral diversity through multiple introductions and in situ evolution
Dengue virus surveillance in Singapore reveals high viral diversity through multiple introductions and in situ evolution
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DOI：
10.1016/j.meegid.2011.10.012
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发表时间：
2012-01-01
影响因子：
3.2
通讯作者：
Lee-Ching Ng
中科院分区：
文献类型：
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作者：
Lee, Kim-Sung;Lo, Sharon;Lee-Ching Ng
登革热是一种媒介传播疾病，给热带和亚热带国家造成了巨大负担。过去20年来，登革热疫情变得更加广泛、严重和频繁。这项研究旨在了解新加坡大都市中登革热病毒的动态。从新加坡（2008-2010）人类血清中获得的所有四种登革热血清型（DENV-1-DENV-4）的包膜蛋白基因序列表明，不断的病毒引入和原位进化有助于新加坡的病毒多样性，并在形成该岛国登革热流行病学方面发挥着重要作用。鉴于新加坡位于登革热高流行地区及其作为区域旅行和贸易中心的作用，这里报告的登革热病毒的多样性可能反映了该地区持续存在的登革热疫情。尽管 DENV-2 的世界性基因型仍然是新加坡流行的主要毒株，但我们发现了原位进化的证据，这可能会导致病毒的适应性得到改善。虽然我们之前已经表明，登革热主要血清型的变化可以作为即将爆发的警告，但我们目前的数据表明，即使在主要血清型没有变化的情况下，主要病毒进化枝的替换也可能预示着登革热传播可能增加。新加坡流行的登革热病毒高度多样化，这种情况可能为选择更高适应度的菌株提供充足的机会，从而在伊蚊种群数量较少的情况下增加了疫情爆发的风险。 (C) 2011 Elsevier B.V. 保留所有权利。
Dengue fever, a vector-borne disease, has caused tremendous burden to countries in the tropics and sub tropics. Over the past 20 years, dengue epidemics have become more widespread, severe and frequent. This study aims to understand the dynamics of dengue viruses in cosmopolitan Singapore. Envelope protein gene sequences of all four dengue serotypes (DENV-1-DENV-4) obtained from human sera in Singapore (2008-2010) revealed that constant viral introductions and in situ evolution contribute to viral diversity in Singapore and play important roles in shaping the epidemiology of dengue in the island state. The diversity of dengue viruses reported here could be a reflection of the on-going dengue situation in the region given Singapore's location in a dengue hyperendemic region and its role as the regional hub for travels and trade. Though cosmopolitan genotype of DENV-2 has remained as the predominant strain circulating in Singapore, we uncovered evidence of in situ evolution which could possibly result in viruses with improved fitness. While we have previously shown that a switch in the predominant dengue serotype could serve as a warning for an impending outbreak, our current data shows that a replacement of a predominant viral clade, even in the absence of a switch in predominant serotype, could signal a possible increase in dengue transmission. The circulating dengue viruses in Singapore are highly diverse, a situation which could offer ample opportunities for selection of strains of higher fitness, thus increasing the risk of outbreaks despite a low Aedes population. (C) 2011 Elsevier B.V. All rights reserved.