科学美国人(翻译):疟疾蚊子在睡前叮咬 2020.05.14

cathy0301 2020-05-24 934 阅读
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Malaria Mosquitoes Are Biting before Bed-Net Time

疟疾蚊子在睡前叮咬

More than 200 million people get malaria each year. And about half a million die—mostly in Africa, many of them children. And those staggering numbers are an improvement. Malaria deaths have been cut in half since 2000. In many places, a remarkably simple tool has led the fight: bed nets treated with a mild insecticide that stop mosquitoes from biting people in their sleep.

每年有2亿多人感染疟疾。大约有50万人死亡——大部分在非洲,其中很多是儿童。这些惊人的数字是一个进步。自2000年以来,疟疾死亡人数减少了一半。在许多地方,一种非常简单的工具引领了这场斗争:用温和的杀虫剂处理过的蚊帐,可以防止蚊子在人们睡觉时叮咬他们。

Both people and mosquitoes are pawns in the malaria transmission cycle. If an infected person gets bitten by a mosquito, the parasite gets picked up along within the blood meal. That mosquito can then transfer the parasite to the next person it bites. Bed nets help stop mosquitoes from easy attacks on motionless sleepers. But now some mosquitoes seem to be giving up the night shift.

“Malaria mosquitos in Africa tend to shift their biting behavior.”

人类和蚊子都是疟疾传播周期中的棋子。如果受感染的人被蚊子叮咬,寄生虫就会在血液中传播。然后,蚊子可以将寄生虫转移到它叮咬的下一个人身上。蚊帐可以防止蚊子轻易袭击不睡觉的人。但是现在一些蚊子似乎放弃了上夜班。 “非洲的疟蚊倾向于改变它们的叮咬行为。”

Entomologist Eunho Suh from Penn State University’s Center for Infectious Disease Dynamics.

“Normally they tend to bite people during the night, but because of extensive use of bed nets, these mosquitoes started biting in the early evening or in the morning.”

来自宾夕法尼亚州立大学传染病动力学中心的昆虫学家Eunho Suh说。“通常它们会在晚上叮咬人,但由于大量使用蚊帐,这些蚊子在傍晚或清晨开始叮咬。”

Suh and his team wanted to know whether observed change in biting time had any impact on malaria transmission. Back in the lab, they presented Anopheles mosquitoes with the opportunity to feed on blood at 6 P.M., at midnight and at 6 A.M. When the laboratory was kept at an even 80 degrees Fahrenheit, evening and morning biters were no more or less likely to become infectious than the midnight biters.

Suh和他的团队想知道观察到的咬人时间的变化是否对疟疾传播有影响。回到实验室,他们让按蚊有机会在下午6点吸食血液,午夜和早上6点当实验室被保持在华氏80度时,晚上和早上的咬人与午夜的咬人相比,感染的可能性没有增加或减少。

But in the real world of the warm and humid tropics, nighttime is slightly cooler than daytime. And when the researchers introduced that temperature variation, the evening biters were a lot more likely to have potent malaria parasites. The results are in the journal Nature Ecology & Evolution. [Eunho Suh et al., The influence of feeding behaviour and temperature on the capacity of mosquitoes to transmit malaria]

但在温暖潮湿的热带地区,夜间的温度比白天略低。当研究人员引入这种温度变化时,夜猫子更有可能携带强效疟原虫。研究结果发表在《自然生态与进化》杂志上。

“Not all mosquito bites are equal. So mosquitoes biting in the evening can have the highest transmission potential, compared to mosquitoes biting at midnight or the morning.” Suh thinks that the difference in the likelihood of mosquitoes becoming infectious has to do with the way that the malaria parasite matures. The parasites have a tougher time developing when mosquitoes are too warm. But if a mosquito picks up the parasites from blood at around dusk, those parasites have more hours of cooler nighttime temps to complete their development.

“并不是所有的蚊子叮咬都是一样的。因此,与在午夜或清晨叮咬的蚊子相比,在晚上叮咬的蚊子可能具有最高的传播潜力。Suh认为蚊子变得有传染性的可能性的不同与疟原虫成熟的方式有关。当蚊子太热时,寄生虫很难生长。但是,如果蚊子在黄昏时分从血液中捕获寄生虫,这些寄生虫就有更多的时间在夜间温度较低的环境中完成发育。

Next, Suh wants to conduct a similar study of wild mosquitoes and wild malaria parasites in Africa to see if the results from his lab mosquitoes hold up. Either way, bed nets will remain an important tool. But understanding the enemy’s behavior is always crucial information in any battle.

接下来,Suh想在非洲对野生蚊子和野生疟原虫进行类似的研究,看看他的实验室蚊子的研究结果是否成立。不管怎样,蚊帐仍将是一个重要的工具。但是了解敌人的行为在任何战斗中都是至关重要的信息。

—Jason G. Goldman

—来自Jason G. Goldman


Malaria Mosquitoes Are Biting before Bed-Net Time

疟疾蚊子在睡前叮咬

More than 200 million people get malaria each year. And about half a million die—mostly in Africa, many of them children. And those staggering numbers are an improvement. Malaria deaths have been cut in half since 2000. In many places, a remarkably simple tool has led the fight: bed nets treated with a mild insecticide that stop mosquitoes from biting people in their sleep.

每年有2亿多人感染疟疾。大约有50万人死亡——大部分在非洲,其中很多是儿童。这些惊人的数字是一个进步。自2000年以来,疟疾死亡人数减少了一半。在许多地方,一种非常简单的工具引领了这场斗争:用温和的杀虫剂处理过的蚊帐,可以防止蚊子在人们睡觉时叮咬他们。

Both people and mosquitoes are pawns in the malaria transmission cycle. If an infected person gets bitten by a mosquito, the parasite gets picked up along within the blood meal. That mosquito can then transfer the parasite to the next person it bites. Bed nets help stop mosquitoes from easy attacks on motionless sleepers. But now some mosquitoes seem to be giving up the night shift.

“Malaria mosquitos in Africa tend to shift their biting behavior.”

人类和蚊子都是疟疾传播周期中的棋子。如果受感染的人被蚊子叮咬,寄生虫就会在血液中传播。然后,蚊子可以将寄生虫转移到它叮咬的下一个人身上。蚊帐可以防止蚊子轻易袭击不睡觉的人。但是现在一些蚊子似乎放弃了上夜班。 “非洲的疟蚊倾向于改变它们的叮咬行为。”

Entomologist Eunho Suh from Penn State University’s Center for Infectious Disease Dynamics.

“Normally they tend to bite people during the night, but because of extensive use of bed nets, these mosquitoes started biting in the early evening or in the morning.”

来自宾夕法尼亚州立大学传染病动力学中心的昆虫学家Eunho Suh说。“通常它们会在晚上叮咬人,但由于大量使用蚊帐,这些蚊子在傍晚或清晨开始叮咬。”

Suh and his team wanted to know whether observed change in biting time had any impact on malaria transmission. Back in the lab, they presented Anopheles mosquitoes with the opportunity to feed on blood at 6 P.M., at midnight and at 6 A.M. When the laboratory was kept at an even 80 degrees Fahrenheit, evening and morning biters were no more or less likely to become infectious than the midnight biters.

Suh和他的团队想知道观察到的咬人时间的变化是否对疟疾传播有影响。回到实验室,他们让按蚊有机会在下午6点吸食血液,午夜和早上6点当实验室被保持在华氏80度时,晚上和早上的咬人与午夜的咬人相比,感染的可能性没有增加或减少。

But in the real world of the warm and humid tropics, nighttime is slightly cooler than daytime. And when the researchers introduced that temperature variation, the evening biters were a lot more likely to have potent malaria parasites. The results are in the journal Nature Ecology & Evolution. [Eunho Suh et al., The influence of feeding behaviour and temperature on the capacity of mosquitoes to transmit malaria]

但在温暖潮湿的热带地区,夜间的温度比白天略低。当研究人员引入这种温度变化时,夜猫子更有可能携带强效疟原虫。研究结果发表在《自然生态与进化》杂志上。

“Not all mosquito bites are equal. So mosquitoes biting in the evening can have the highest transmission potential, compared to mosquitoes biting at midnight or the morning.” Suh thinks that the difference in the likelihood of mosquitoes becoming infectious has to do with the way that the malaria parasite matures. The parasites have a tougher time developing when mosquitoes are too warm. But if a mosquito picks up the parasites from blood at around dusk, those parasites have more hours of cooler nighttime temps to complete their development.

“并不是所有的蚊子叮咬都是一样的。因此,与在午夜或清晨叮咬的蚊子相比,在晚上叮咬的蚊子可能具有最高的传播潜力。Suh认为蚊子变得有传染性的可能性的不同与疟原虫成熟的方式有关。当蚊子太热时,寄生虫很难生长。但是,如果蚊子在黄昏时分从血液中捕获寄生虫,这些寄生虫就有更多的时间在夜间温度较低的环境中完成发育。

Next, Suh wants to conduct a similar study of wild mosquitoes and wild malaria parasites in Africa to see if the results from his lab mosquitoes hold up. Either way, bed nets will remain an important tool. But understanding the enemy’s behavior is always crucial information in any battle.

接下来,Suh想在非洲对野生蚊子和野生疟原虫进行类似的研究,看看他的实验室蚊子的研究结果是否成立。不管怎样,蚊帐仍将是一个重要的工具。但是了解敌人的行为在任何战斗中都是至关重要的信息。

—Jason G. Goldman

—来自Jason G. Goldman


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