发现助流感传播的关键因子

　　

近期几起人禽流感病例震惊国内外，为何流感盛行于冬季，是什么样的因素在控制病毒的流行。了解流感传播的路径对疾病防控有重要的意义。

 

俄勒冈州立大学海洋和大气科学院的科研工作者发表在PNAS的一篇研究性文章也许能解开这道难题。科学家发现绝对湿度与流感病毒的生存和传播之间的联系，这可能解释为什么流感在温带国家的冬季流行。

 

据EurekAlert介绍，过去的研究没能发现相对湿度和病毒传播或生存之间的显著联系，但是Jeffrey Shaman 和Melvin Kohn如今说重要的因素是绝对湿度而非相对湿度。绝对湿度是对空气中水的总量的量化，而相对湿度测量的是空气中的水与水饱和程度的比例，它强烈地受温度影响。长久以来湿度被认为影响着病毒的传播，因为空气中的水被认为可以影响空气传播的液滴中的病毒颗粒的传播和生存。

 

Jeffrey Shaman等研究者重新分析了来自此前发现了病毒传播和相对湿度之间微小联系研究的数据，结果证明了流感病毒的传播和绝对湿度之间有更加强烈的相关性。Kohn及其同事发现，流感病毒在绝对湿度更低的环境下生存时间更长，这可能解释它在更冷、更干燥的月份里更有效传播的原因。绝对湿度为什么会影响病毒生存的准确原因仍然有待确定。

 

研究者声称，在急诊室等关键区域增加湿度可能减少流感的传播。

 

生物通推荐原文摘要：Absolute humidity modulates influenza survival, transmission and seasonality

【Abstract】

Influenza A incidence peaks during winter in temperate regions. The basis for this pronounced seasonality is not understood, nor is it well documented how influenza A transmission principally occurs. Previous studies indicate that relative humidity (RH) affects both influenza virus transmission (IVT) and influenza virus survival (IVS). Here, we reanalyze these data to explore the effects of absolute humidity on IVT and IVS. We find that absolute humidity (AH) constrains both transmission efficiency and IVS much more significantly than RH. In the studies presented, 50% of IVT variability and 90% of IVS variability are explained by AH, whereas, respectively, only 12% and 36% are explained by RH. In temperate regions, both outdoor and indoor AH possess a strong seasonal cycle that minimizes in winter. This seasonal cycle is consistent with a wintertime increase in IVS and IVT and may explain the seasonality of influenza. Thus, differences in AH provide a single, coherent, more physically sound explanation for the observed variability of IVS, IVT and influenza seasonality in temperate regions. This hypothesis can be further tested through future, additional laboratory, epidemiological and modeling studies.