全球抗疟的最新武器？蚊子 | 盖茨笔记

About 10 years ago, the African country of Djibouti had nearly succeeded in wiping out malaria. The country’s leaders hoped that getting rid of the disease would help them attract new investment, development, and tourism.

大约10年前，非洲国家吉布提几乎成功地消灭了疟疾。吉布提的领导人希望消除这种疾病能够为他们吸引新的投资、发展和旅游。

Then suddenly the disease roared back. Cases surged from just 27 in 2012, to more than 73,000 in 2020—a huge number for this East African nation of just one million people.

然而，疟疾却突然卷土重来。确诊病例从2012年的27例猛增至2020年的73,000多例——对于这个仅有100万人口的东非国家来说，这是一个巨大的数字。

The cause?

原因是什么呢？

A highly invasive mosquito that had migrated from South Asia and the Arabian Peninsula into Africa.

一种入侵性蚊子从南亚和阿拉伯半岛迁移到了非洲。

This pest—the Anopheles stephensi mosquito—has now emerged as one of the biggest threats to malaria elimination in sub-Saharan Africa. Since establishing a beachhead in Djibouti, An. stephensi mosquitoes have been detected in Ethiopia, Sudan, Somalia, Kenya and as far away as Nigeria and Ghana, in West Africa. According to one study, if this mosquito is left unchecked an additional 126 million people on the continent will be at risk of malaria.

这种害虫——斯氏按蚊（Anopheles stephensi）——如今已经成为撒哈拉以南非洲消灭疟疾的最大威胁之一。在扎根吉布提后，斯氏按蚊已经在埃塞俄比亚、苏丹、索马里、肯尼亚以及远在西非的尼日利亚和加纳等地被检测到。根据一项研究，如果不对这种蚊子加以控制，非洲大陆上将有另外1.26亿人面临疟疾侵袭的风险。

What makes An. stephensi particularly dangerous is where it has chosen to reside. Unlike other malaria-carrying mosquitoes in Africa that primarily breed in rural areas, An. stephensi thrives in urban environments. Cities are already home to 40 percent of the population in sub-Saharan Africa and continue to experience rapid growth, creating a fertile habitat for this mosquito. Making matters worse, An. stephensi has been found to be resistant to many of the insecticides used to control mosquito populations. And they bite in the evening before bedtime—not in the middle of the night like other mosquitoes—making bed nets less effective as protection.

斯氏按蚊构成威胁的特殊性在于其选择的栖息地。不同于非洲其他携带疟疾的蚊子，斯氏按蚊可以在城市环境中大量繁殖，而其他蚊子主要在农村繁殖。撒哈拉以南非洲地区40%的人口居住在城市，而城市人口还在继续快速增长，为这种蚊子提供了有利的生存环境。更糟糕的是，人们发现斯氏按蚊对许多用于控制蚊子数量的杀虫剂产生了抗性。同时，它们叮咬人的时间是在晚上临睡前，其他蚊子则在半夜，这使得蚊帐的保护效果大打折扣。

But this story doesn’t end here.

好在这个故事并未就此结束。

In 2018, the government of Djibouti, in search for a new approach to combat these urban invaders, heard about a biotechnology company called Oxitec that has a potentially game-changing solution to mosquito control.

2018年，吉布提政府试图寻求一种新方法来应对这些城市入侵者，并得知一家名为Oxitec的生物技术公司拥有可能改变局面的蚊虫控制方案。

The fight against mosquitoes and the diseases they carry has always been a game of cat and mouse. Humans develop new interventions—like bed nets, insecticides, and treatments—to protect themselves from mosquitoes. Mosquitoes, meanwhile, have an incredible capacity to adapt, allowing them to eventually dodge or develop resistance to the latest control methods. Then humans respond with more innovations to outsmart the mosquitoes. And so on.

与蚊子及其传播疾病的斗争如同一场猫鼠游戏。人类不断开发新的干预措施，如蚊帐、杀虫剂和相应治疗，以保护自己免受蚊子的侵扰。而与此同时，蚊子拥有惊人的适应能力，能够躲避或对最新的干预措施产生抗性。于是人类就需要采取更多的创新措施来战胜蚊子。如此循环往复。

Oxitec, however, aims to change this game from cat versus mouse to mouse versus mouse. Or in this case, mosquito versus mosquito. Oxitec specializes in using mosquitoes to fight other mosquitoes. With its genetic technology, Oxitec has already developed mosquitoes to effectively combat the dengue fever–carrying mosquito, Aedes aegypti, in Brazil. Now Oxitec plans to use the same technology to help African governments control An. stephensi and reduce the spread of malaria.

Oxitec的目标是将这场游戏从猫与老鼠，转变为老鼠与老鼠，或在这个故事中，就是蚊子与蚊子。Oxitec专注于利用蚊子来对抗其他蚊子，凭借其基因技术，Oxitec已经成功研发出可以有效对抗传播登革热的埃及伊蚊（Aedes aegypti）的蚊子，并在巴西取得了成功。现在，Oxitec计划使用相同的技术，帮助非洲国家控制斯氏按蚊，减少疟疾的传播。

Here’s how Oxitec’s technology would work against An. stephensi mosquitoes: Oxitec male mosquitoes carry a special gene to prevent their female offspring from surviving into adulthood. (Only female mosquitoes bite and spread malaria.)  Released into the wild, the male Oxitec mosquitoes mate with wild female mosquitoes. All the female offspring die. All the male progeny, which don’t bite, will survive and go on to mate with other wild females. With sustained releases of male Oxitec mosquitoes, more females die off, dramatically reducing the mosquito population and the spread of malaria. After the mosquito releases stop, however, because half of the gene’s carriers (the females) cannot survive, the gene steadily declines and disappears from the mosquito population within a few generations.

让我们简单了解一下Oxitec的基因技术应对斯氏按蚊的原理。Oxitec的雄蚊携带一种特殊基因，可以阻止其雌性后代存活至成年期（只有雌蚊会叮咬并传播疟疾）。这些雄蚊被释放到野外后，与野生雌蚊交配，其繁衍后代中所有雌蚊都会死亡，而不会叮咬人类的雄蚊可以生存并继续与其他野生雌蚊交配。通过持续释放Oxitec雄蚊，更多的雌蚊会死亡，从而大大减少了蚊子数量和疟疾的传播。但停止释放后，由于携带这种特殊基因的半数蚊子（雌蚊）无法存活，这种基因会在几代内逐渐减少，并从蚊子种群内消失。

Genetic technology like Oxitec’s understandably raises many questions. Is it safe? What are the lasting environmental impacts? Here’s what’s important to know:

毫无疑问，Oxitec使用的基因技术会引发许多问题。这项技术是否安全？携带特殊基因的蚊子被释放，是否会在环境中产生持久的影响？以下是我们需要了解的重要信息：

Because it’s passed through mating, the gene the Oxitec male mosquitoes carry only targets the An. stephensi mosquitoes. It doesn’t have any impact on other insects and cannot be established in the local ecosystem. After evaluating the potential risk of genetically modified mosquitoes, the U.S. Food and Drug Administration in 2016 and the EPA in 2022 have confirmed that the Oxitec mosquitoes do not pose a threat to humans or the environment. More than one billion Oxitec mosquitoes have been released worldwide, with no negative impacts. In Brazil, the Oxitec Aedes aegypti mosquitoes have been so successful in reducing the spread of dengue fever that they are in demand by communities, governments, and businesses in Brazil. Homeowners can even buy a kit to raise the mosquitoes in their own backyards. (If you want to learn more about this technology, I encourage you to visit the Oxitec website and the Centers for Disease Control and Prevention.)

由于基因通过交配传递，Oxitec雄蚊携带的基因仅对斯氏按蚊产生作用，不会影响其他昆虫，也无法在当地生态系统中生存下来。在评估了基因改造蚊子的潜在风险后，美国食品药品监督管理局于2016年以及美国环境保护局于2022年确认，Oxitec蚊子对人类及环境没有威胁。全球范围内已有超过十亿只Oxitec蚊子被释放，未发现任何负面影响。在巴西，针对埃及伊蚊的Oxitec蚊子成功减少登革热传播，并受到了巴西的社区、政府和企业的欢迎。业主们甚至可以购买一个套装，在自家后院里饲养Oxitec蚊子。（如果你想进一步了解这项技术，我建议你访问Oxitec官网或美国疾病控制与预防中心。）

Last year, the government of Djibouti formed a partnership with Oxitec, Association Mutualis (a non-profit public health organization in Djibouti), and the Djibouti National Malaria Control Programme to use this new technology to defeat An. stephensi.

去年，吉布提政府与Oxitec、Association Mutualis（吉布提的一家非营利公共卫生组织）以及吉布提国家疟疾防治计划建立了合作伙伴关系，利用这项新技术来消灭斯氏按蚊。

No Oxitec mosquitoes have been released in Djibouti during the current pilot phase of the project. But the government of Djibouti expects to move forward with the first releases of Oxitec mosquitoes next year in Djibouti’s capital city, where 70 percent of the population live.

当前项目仍处于试点阶段，吉布提尚未释放Oxitec蚊子。然而，吉布提政府计划明年在首都进行首次Oxitec蚊子的释放，那里居住着该国70%的人口。

This solution is being pursued with the support of the people of Djibouti. The government of Djibouti, Oxitec, and its local partners have been working together to educate and engage the public about this technology, going door to door to listen to their concerns, and ensuring all the communities’ questions have been addressed before moving forward with the release of the mosquitoes. Local support has been outstanding to date.

这项解决方案得到了吉布提人民的支持。吉布提政府、Oxitec及其当地合作伙伴一直在共同努力，对公众进行有关这项技术的教育和宣传，挨家挨户地倾听他们的担忧，并确保在释放蚊子之前解答社区的所有问题。迄今为止，当地的支持率十分可观。

To end malaria, we need many new tools and innovations to reduce the burden of this disease and move the world closer to eradication. I’m excited about the potential of Oxitec’s technology to help Djibouti and the rest of Africa achieve this goal.

为了终结疟疾，我们需要许多新的工具和创新，以减轻这种疾病的负担，使世界更接近根除疟疾的目标。我对Oxitec公司的技术帮助吉布提和非洲其他国家实现这一目标的潜力感到振奋。