Could Environment Affect the Mutation of H1N1 Influenza Virus?

H1N1 subtype influenza A viruses are the most common type of influenza A virus to infect humans. The two major outbreaks of the virus in 1918 and 2009 had a great impact both on human health and social development. Though data on their complete genome sequences have recently been obtained, the evolution and mutation of A/H1N1 viruses remain unknown to this day. Among many drivers, the impact of environmental factors on mutation is a novel hypothesis worth studying. Here, a geographically disaggregated method was used to explore the relationship between environmental factors and mutation of A/H1N1 viruses from 2000-2019. All of the 11,721 geo-located cases were examined and the data was analysed of six environmental elements according to the time and location (latitude and longitude) of those cases. The main mutation value was obtained by comparing the sequence of the influenza virus strain with the earliest reported sequence. It was found that environmental factors systematically affect the mutation of A/H1N1 viruses. Minimum temperature displayed a nonlinear, rising association with mutation, with a maximum similar to 15 degrees C. The effects of precipitation and social development index (nighttime light) were more complex, while population density was linearly and positively correlated with mutation of A/H1N1 viruses. Our results provide novel insight into understanding the complex relationships between mutation of A/H1N1 viruses and environmental factors.

甲型H1N1流感病毒是感染人类的最常见甲型流感病毒类型。该病毒在1918年和2009年的两次大爆发对人类健康和社会发展都产生了重大影响。尽管最近已经获得了它们完整基因组序列的数据，但甲型H1N1病毒的进化和突变至今仍不为人知。在众多驱动因素中，环境因素对突变的影响是一个值得研究的新假说。在此，采用一种按地理位置细分的方法来探究2000 - 2019年环境因素与甲型H1N1病毒突变之间的关系。对所有11721例有地理位置信息的病例进行了检查，并根据这些病例的时间和位置（纬度和经度）分析了六种环境要素的数据。通过将流感病毒株的序列与最早报道的序列进行比较，获得了主要的突变值。研究发现环境因素系统性地影响甲型H1N1病毒的突变。最低温度与突变呈现非线性的上升关联，在大约15℃时达到最大值。降水量和社会发展指数（夜间灯光）的影响更为复杂，而人口密度与甲型H1N1病毒的突变呈线性正相关。我们的研究结果为理解甲型H1N1病毒突变与环境因素之间的复杂关系提供了新的视角。