Spatio-temporal Transmission Of Dengue Fever Based On Gene Sequence And Case Data

Dengue fever(DF)is an acute infectious disease caused by dengue virus infection in humans and primates,which is mainly concentrated in tropical and subtropical regions,and Southeast Asian countries are the hardest hit by dengue fever,and the coastal provinces in southern China are also affected by the epidemic as a result.To explore the epidemiological characteristics and patterns of dengue fever,this paper analyzed the distribution patterns of dengue fever cases,explored the transmission patterns of dengue virus,and assessed the highrisk areas of dengue fever based on dengue fever case data and dengue virus gene sequence data during 2010-2014,using spatial statistical methods,phylogenetic analysis methods,and D-S evidence fusion theory,respectively.The main research contents include.(1)Study on the spatial distribution pattern of dengue fever.Based on dengue case data,the spatial correlation of case distribution was firstly analyzed and the aggregation and anomaly areas were detected;then the local aggregation of cases was compared with the kernel density estimation,and the results showed that the kernel density estimates of dengue case points in the L-H and H-L anomaly areas were generally low,and there were no case points in the L-H anomaly area.Finally,the spatial distribution of the probability of dengue occurrence from a macroscopic perspective was simulated.The results showed that the highest risk of dengue outbreak existed in the border areas of Pakistan and India,Cambodia,Malaysia,Guangdong Province and Yunnan Province in China.(2)Phylogenetic analysis of dengue virus gene sequences and metric of virus transmission network.Based on the viral gene sequence data,phylogenetic analysis was applied to explore the evolutionary relationships among dengue viruses and to derive the spatial and temporal transmission paths of dengue viruses.The results showed that there were 18 statistically significant cross-regional virus transmission events in the study area,with Sri Lanka,Vietnam,Singapore and New Caledonia dominating the virus transmission.In contrast,dengue virus in China had a tendency to spread from coastal areas to the interior.After using network analysis to measure the transmission capacity of virus transmission network nodes,the spatial distribution of the probability of dengue occurrence from a microscopic perspective was obtained by interpolation,and the results indicated that the high-risk areas were distributed in Fujian Province,Guangxi Province,Guangdong Province,and Vietnam,India,and Singapore in China.(3)The D-S evidence theory was applied to fuse the macro(based on local K function)and micro(based on interpolation of virus network nodes)spatial distribution of dengue occurrence probability to obtain the final risk area detection results.Comparing the macro,micro and fused local dengue risk areas,the results showed that the risk of dengue occurrence was significantly higher in south-central India,Sri Lanka,southern Laos,northeast and southeast of Vietnam,and southern Cambodia compared to the pre-fusion areas.In addition,some areas in Hainan and Yunnan provinces of China also became areas with higher risk of dengue occurrence;while some areas in Yunnan,Jiangxi,Hunan and Guangdong provinces all had a small increase in the risk of dengue occurrence.This paper measures the risk areas of dengue fever from both macroscopic and microscopic perspectives,and finally integrates them to help improve the accuracy of the study results and provide a reference basis for the prevention,control and management of infectious diseases.