University of Iowa, Iowa City, Iowa, United States of America.
Florida State University, Tallahassee, Florida, United States of America.
PLoS One. 2019 Mar 6;14(3):e0212511. doi: 10.1371/journal.pone.0212511. eCollection 2019.
Given substantial regional differences in absolute humidity across the US and our understanding of the relationship between absolute humidity and influenza, we may expect important differences in regional seasonal influenza activity. Here, we assessed cross-seasonal influenza activity by comparing counts of positive influenza A and B rapid test results during the influenza season versus summer baseline periods for the 2016/2017 and 2017/2018 influenza years. Our analysis indicates significant regional patterns in cross-seasonal influenza activity, with relatively fewer influenza cases during the influenza season compared to summertime baseline periods in humid areas of the US, particularly in Florida and Hawaii. The cross-seasonal ratios vary from year-to-year and influenza type, but the geographic patterning of the ratios is relatively consistent. Mixed-effects regression models indicated absolute humidity during the influenza season was the strongest predictor of cross-seasonal influenza activity, suggesting a relationship between absolute humidity and cross-seasonal influenza activity. There was also evidence that absolute humidity during the summer plays a role, as well. This analysis suggests that spatial variation in seasonal absolute humidity levels may generate important regional differences in seasonal influenza activity and dynamics in the US.
鉴于美国各地绝对湿度存在显著差异，以及我们对绝对湿度与流感之间关系的理解，我们可能预计季节性流感活动在区域上会存在重要差异。在这里，我们通过比较 2016/2017 和 2017/2018 流感年流感季节与夏季基线期间的阳性流感 A 和 B 快速检测结果的计数，评估了跨季节流感活动。我们的分析表明，跨季节流感活动存在显著的区域模式，与夏季基线相比，美国潮湿地区（尤其是佛罗里达州和夏威夷州）的流感季节流感病例相对较少。跨季节比值因年份和流感类型而异，但比值的地理模式相对一致。混合效应回归模型表明，流感季节的绝对湿度是跨季节流感活动的最强预测因子，表明绝对湿度与跨季节流感活动之间存在关系。夏季绝对湿度也起到了一定作用。这项分析表明，季节性绝对湿度水平的空间变化可能会在美国产生季节性流感活动和动态的重要区域差异。
