Association of influenza virus isolation with environmental factors in mainland China based on remote sensing and GIS

Although influenza is a common disease with characteristics of seasonality, the determinants of each season's onset, magnitude, and duration are poorly understood. This paper focuses on the role of environmental factors in spread and epidemic of seasonal influenza and explores the environmental explanatory factors for different types of influenza in mainland China. It also introduces satellite remote sensing as an important data obtaining approach, and highlights the potential of using satellite images for monitoring dynamics of climate and landscapes related to the spread of seasonal influenza. Applying Geographic Information System (GIS) technique combining with traditional statistical analysis, the paper uses influenza virus isolation rate (VIR) as the measure of influenza activity and analyzed its association with environmental factors. The results show that the spread and epidemic of influenza is influenced by various environmental factors, among which the temperature and humidity are seemed to be the determinants. However, the impacts of the environmental factors to different types of virus are varied. Low temperature and humidity conditions arere associated with a higher activity of both influenza A and B. On the contrary, high temperature and humidity conditions are associated with a higher activity of influenza A, but are associated with only a moderate or low, less consistent increase in the activity of influenza B. Recognition of this association could lead to better understanding of the mechanisms of emergence of influence epidemics and provide scientific evidence for controlling influenza.