College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, United States of America.
PLoS Biol. 2010 Feb 23;8(2):e1000316. doi: 10.1371/journal.pbio.1000316.
Much of the observed wintertime increase of mortality in temperate regions is attributed to seasonal influenza. A recent reanalysis of laboratory experiments indicates that absolute humidity strongly modulates the airborne survival and transmission of the influenza virus. Here, we extend these findings to the human population level, showing that the onset of increased wintertime influenza-related mortality in the United States is associated with anomalously low absolute humidity levels during the prior weeks. We then use an epidemiological model, in which observed absolute humidity conditions temper influenza transmission rates, to successfully simulate the seasonal cycle of observed influenza-related mortality. The model results indicate that direct modulation of influenza transmissibility by absolute humidity alone is sufficient to produce this observed seasonality. These findings provide epidemiological support for the hypothesis that absolute humidity drives seasonal variations of influenza transmission in temperate regions.
在温带地区，观察到的冬季死亡率增加主要归因于季节性流感。最近对实验室实验的重新分析表明，绝对湿度强烈调节流感病毒的空气传播存活和传播。在这里，我们将这些发现扩展到人口水平，表明美国冬季与流感相关的死亡率增加的开始与前几周异常低的绝对湿度水平有关。然后，我们使用一个流行病学模型，其中观察到的绝对湿度条件调节流感传播率，成功地模拟了观察到的与流感相关的死亡率的季节性循环。该模型结果表明，仅通过绝对湿度直接调节流感传播率就足以产生这种观察到的季节性。这些发现为绝对湿度驱动温带地区流感传播季节性变化的假说提供了流行病学支持。
