發現一種微生物能阻止蚊子傳播瘧疾

Although COVID-19 is dominating headlines, other diseases don't let up just because we have a pandemic - and malaria is still as dangerous as ever.

雖然新冠病毒一直是人們最關注的問題，但其他疾病也不會因爲我們有疫情就停止傳播。瘧疾的危險性就絲毫沒有降低。

In 2018, the World Health Organisation estimated 228 million cases of the mosquito-borne disease, and 405,000 deaths.

2018年，世界衛生組織估計有2.28億例蚊媒疾病，造成405,000人死亡。

But a new study may have found a brand new, highly effective way to stop the spread – and it was inside the mosquito all along.

但一項新研究可能已經找到了一種全新的、高效的方法阻止瘧疾傳播，其關鍵就在蚊子體內。

The team discovered that a new type of spore-forming single-celled microbe found in mosquitoes, which they've called Microsporidia MB, has the amazing ability to stop the transmission of Plasmodium falciparum – the parasitic protozoan which causes most malaria cases.

研究團隊在蚊子體內發現一種新型的孢子形成的單細胞微生物，稱之爲Microsporidia MB，它有阻止惡性瘧原蟲傳播的驚人能力。瘧原蟲是引起大多數瘧疾感染的寄生原生動物。

It also doesn't seem to hurt the mosquito, meaning that if we can increase the prevalence of Microsporidia MB in local mosquito populations, it could be a good way to stop malaria in its tracks without having to mess up the rest of the ecosystem.

它似乎對蚊子沒有傷害，如果我們能在當地蚊子種羣中提高Microsporidia MB的感染率，就會成爲阻止瘧疾蔓延的好方法，還不會破壞生態系統的其他部分。

"Here, we characterise an apparently non-pathogenic microsporidian from field populations of Anopheles arabiensis [a species of mosquito] in Kenya," the team writes in a new paper.

研究團隊在新的論文中寫道：“現在我們研究了肯尼亞的阿拉伯按蚊（一種蚊子）野外種羣中一種明顯的非致病性小孢子蟲。”

"As a microbe that impairs Plasmodium transmission that is non-virulent and vertically transmitted, Microsporidia MB could be investigated as a strategy to limit malaria transmission."

“因爲Microsporidia MB 是一種阻止瘧原蟲傳播的微生物，它無毒而且垂直傳播，所以可以用它來控制瘧疾的傳播。”

The idea that a mosquito microbe could be stopping the transmission of a disease isn't exactly new. Wolbachia, a genus of bacteria that naturally occurs in mosquito populations, has shown incredible potential for wiping out dengue and other mosquito-borne infections.

認爲蚊子體內微生物能阻止疾病傳播的想法並不新鮮。沃爾巴克氏菌屬細菌就是蚊子種羣內自然產生的細菌，在消滅登革熱和其他蚊媒傳染病方面有驚人的潛力。

"We are already using a transmission-blocking symbiont called Wolbachia to control dengue, a virus transmitted by mosquitoes," University of Glasgow microbiologist Steven Sinkins says.

格拉斯哥大學微生物學家Steven Sinkins說：“我們已經在利用沃爾巴克氏菌這種阻礙傳播的共生菌來控制登革熱，這也是蚊子傳播的病毒。”

"The Microsporidia MB symbiont has some similar characteristics, making it an attractive prospect for developing comparable approaches for malaria control."

“Microsporidia MB共生菌有類似的特點，使我們很有信心地認爲可以利用它研究控制瘧疾的類似方法。”

This research is currently in its early stages – but the team found that when they analysed mosquitoes taken from field studies in Kenya, those with Microsporidia MB did not have the malaria parasite. Even when they let the mosquitoes drink infected blood, the mosquitoes with Microsporidia MB had reduced levels of infection and no signs of the malaria parasite's spores were detected.

這項研究目前處於初級階段，但研究團隊發現他們分析肯尼亞野外研究的蚊子時，帶有Microsporidia MB的蚊子沒有瘧原蟲。甚至在讓它們吸食被感染的血液以後，帶有Microsporidia MB的蚊子的感染風險也會下降，而且沒有發現有瘧原蟲孢子蟲的跡象。

Because Microsporidia MB is passed down the maternal line, once it's in the mosquito population, it's unlikely to be going anywhere. The team found that some areas they tested already had nine percent of the mosquito population with the malaria-busting microbe.

因爲Microsporidia MB是母系遺傳，所以一旦蚊子種羣感染，也不可能傳播給其他昆蟲。研究團隊發現有些測試過的地區已經有9%的蚊子體內有滅瘧微生物了。

The team hopes that with more research we can find out if it's possible to increase the amount of Microsporidia MB in the mosquito population – with the eventual goal of lowering rates of malaria.

研究團隊希望，通過更多研究我們可以瞭解是否有可能提高蚊子種羣中的Microsporidia MB數量，從而最終降低瘧疾感染率。

"Further studies will be needed to determine precisely how Microsporidia MB could be used to control malaria. The next phase of the research will investigate Microsporidia MB dynamics in large mosquito populations in screen house 'semi-field' facilities," says International Centre of Insect Physiology and Ecology microbiologist, Jeremy Herren.

國際昆蟲生理學與生態學中心的微生物學家Jeremy Herren說：“需要進行進一步的研究來準確確定如何利用Microsporidia MB控制瘧疾。下一階段的研究將調查屏蔽屋‘半野外’設備中大量蚊子體內 Microsporidia MB的動態。”

"The results of these studies will give us key information that will be used to determine how we could then disseminate Microsporidia MB for malaria control."

“這些研究結果將爲我們提供關鍵信息，我們能以此來確定如何傳播Microsporidia MB來控制瘧疾 。”