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疟疾蚊虫靠风实现长距离传播
2019-10-03 20:46

非洲萨赫勒地区疟疾蚊子依靠风传播实现长距离迁移,这一成果由美国国立卫生研究院Tovi Lehmann小组近日取得。该研究论文2019年10月2日在线发表于国际学术期刊《自然》。

研究人员介绍,在过去的二十年中,控制疟疾的努力使全球病例数减少了一半,但在非洲大部分地区,负担仍然很高,即使在诸如南非这样的持续大量减少的地区,消除疟疾也未能实现。先前的研究发现,在一年中3至8个月缺乏地表水的地区中疟疾仍然悖论性地存在,这表明某些疟蚊能够长距离迁移。

研究人员通过对高于地面40到290 米的蚊子进行空中采样证实了这一假说。据研究人员所知,这提供了非洲疟疾媒介靠风迁移的第一个证据,因此也证明了它们传播的病原体。在马里萨赫勒地区的617例夜间空中采集中,研究人员从235只按蚊中鉴定出了十个蚊子物种,其中包括主要的疟疾载体coluzzii按蚊。值得注意的是,雌性占研究人员收集的所有蚊子的80%以上。其中,有90%的蚊子在迁徙前已经吸过血,这意味着病原体很可能是由迁徙的雌性进行长距离传播的。

随着海拔高度(采样板高于地面的高度)和雨季的增加,捕获按蚊物种的可能性也增加,但年份和地区之间的变化很小。蚊虫的模拟飞行轨迹表明,在9小时的飞行过程中,夜间平均能够有300 km的位移。每年,在海拔高度超过垂直于盛行风向的100公里直线上,蚊子的数量估计为81000只冈比亚按蚊、600万只coluzzii按蚊和4400万只鳞按蚊。

这些结果提供了令人信服的证据,证明以前以血液为食的数百万疟疾媒介经常迁移数百公里,因此几乎可以肯定地将疟疾传播到了这些距离。因此,能否成功消除疟疾可能取决于能否确定和控制迁移媒介的来源。

附:英文原文

Title: Windborne long-distance migration of malaria mosquitoes in the Sahel

Author: Diana L. Huestis, Adama Dao, Moussa Diallo, Zana L. Sanogo, Djibril Samake, Alpha S. Yaro, Yossi Ousman, Yvonne-Marie Linton, Asha Krishna, Laura Veru, Benjamin J. Krajacich, Roy Faiman, Jenna Florio, Jason W. Chapman, Don R. Reynolds, David Weetman, Reed Mitchell, Martin J. Donnelly, Elijah Talamas, Lourdes Chamorro, Ehud Strobach, Tovi Lehmann

Issue&Volume: 2019-10-02

Abstract: 

Over the past two decades efforts to control malaria have halved the number of cases globally, yet burdens remain high in much of Africa and the elimination of malaria has not been achieved even in areas where extreme reductions have been sustained, such as South Africa1,2. Studies seeking to understand the paradoxical persistence of malaria in areas in which surface water is absent for 3–8 months of the year have suggested that some species of Anopheles mosquito use long-distance migration3. Here we confirm this hypothesis through aerial sampling of mosquitoes at 40–290 m above ground level and provide—to our knowledge—the first evidence of windborne migration of African malaria vectors, and consequently of the pathogens that they transmit. Ten species, including the primary malaria vector Anopheles coluzzii, were identified among 235 anopheline mosquitoes that were captured during 617 nocturnal aerial collections in the Sahel of Mali. Notably, females accounted for more than 80% of all of the mosquitoes that we collected. Of these, 90% had taken a blood meal before their migration, which implies that pathogens are probably transported over long distances by migrating females. The likelihood of capturing Anopheles species increased with altitude (the height of the sampling panel above ground level) and during the wet seasons, but variation between years and localities was minimal. Simulated trajectories of mosquito flights indicated that there would be mean nightly displacements of up to 300 km for 9-h flight durations. Annually, the estimated numbers of mosquitoes at altitude that cross a 100-km line perpendicular to the prevailing wind direction included 81,000 Anopheles gambiae sensu stricto, 6 million A. coluzzii and 44 million Anopheles squamosus. These results provide compelling evidence that millions of malaria vectors that have previously fed on blood frequently migrate over hundreds of kilometres, and thus almost certainly spread malaria over these distances. The successful elimination of malaria may therefore depend on whether the sources of migrant vectors can be identified and controlled.

DOI: 10.1038/s41586-019-1622-4

Source:https://www.nature.com/articles/s41586-019-1622-4

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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