Flu virus' best friend: Low humidity

流感病毒的最大帮凶

© Axel Kock / Adobe Stock

上海译锐翻译        2019-5-20             15:41  

Yale researchers have pinpointed a key reason why people are more likely to get sick and even die from flu during winter months: low humidity.

来自耶鲁的研究人员查明，人们在冬季更容易生病，甚至死于流感的原因就是干燥。

While experts know that cold temperatures and low humidity promote transmission of the flu virus, less is understood about the effect of decreased humidity on the immune system's defenses against flu infection.

尽管专家们了解，低温和干燥会导致流感病毒的传播，但是他们却并不了解湿度减少对免疫系统对抗流感病毒感染所产生的影响。

The Yale research team, led by Akiko Iwasaki, the Waldemar Von Zedtwitz Professor of Immunobiology, explored the question using mice genetically modified to resist viral infection as humans do. The mice were all housed in chambers at the same temperature, but with either low or normal humidity. They were then exposed to the influenza A virus.

耶鲁研究团队领导人，Waldemar Von Zedtwitz免疫学教授Akiko Iwasaki利用老鼠来研究这一问题。经过基因修改的老鼠会像人类一样抵抗病毒感染。老鼠全部处于房间内，所有房间温度相同，但有的湿度正常，有的湿度较低。接下来，所有老鼠都被暴露在流感A型病毒下。

The researchers found that low humidity hindered the immune response of the animals in three ways. It prevented cilia, which are hair-like structures in airways cells, from removing viral particles and mucus. It also reduced the ability of airway cells to repair damage caused by the virus in the lungs. The third mechanism involved interferons, or signaling proteins released by virus-infected cells to alert neighboring cells to the viral threat. In the low-humidity environment, this innate immune defense system failed.

研究人员发现，干燥会从三个方面阻碍动物的免疫反应。它会阻止纤毛，一种位于气道细胞中类似于毛发的结构，将病毒颗粒和黏液移除。此外，干燥还会降低气道细胞修复病毒对肺部所造成损害的能力。第三个影响涉及干扰素或由受病毒感染的细胞所释放的信号蛋白。信号蛋白会警告周围细胞存在病毒威胁。在干燥的环境中，这一先天的防疫抵御系统也失效了。

The study offers insight into why the flu is more prevalent when the air is dry. "It's well known that where humidity drops, a spike in flu incidence and mortality occurs. If our findings in mice hold up in humans, our study provides a possible mechanism underlying this seasonal nature of flu disease," said Iwasaki.

研究还深入了解了为什么流感在气候干燥时会更加普遍。Iwasaki表示：“众所周知，当湿度下降时，流感发病率和死亡率都会激增。如果我们针对老鼠的实验结果也适用于人类，那么我们的研究就找到了可能存在于流感季节特性中的生物机制。”

While the researchers emphasized that humidity is not the only factor in flu outbreaks, it is an important one that should be considered during the winter season. Increasing water vapor in the air with humidifiers at home, school, work, and even hospital environments is a potential strategy to reduce flu symptoms and speed recovery, they said.

The study was published in the Proceedings of the National Academy of Sciences (PNAS).

尽管研究人员们强调，湿度并非流感爆发的唯一因素，但其确是冬季应该考虑的一个重要因素。研究人员表示，家中、学校、单位，甚至是医院当中可增加空气中水蒸汽含量的加湿器是一个潜在的减少流感症状并加速恢复的举措。该研究结果被出版在《美国国家科学院院刊》当中。

Other authors are Eriko Kudo, Eric Song, Laura Yockey, Tasfia Rakib, Patrick Wong, and Robert Homer.

该研究的其他作者包括Eriko Kudo，Eric Song、Laura Yockey、Tasfia Rakib、Patrick Wong和Robert Homer。

本文来源：科学日报  编辑：质控部Susan