Risk Assessment Of The Secondary Transmission By Imported Malaria In Jiangxi Province

Objective:To assess the risk of secondary transmission induced by imported malaria in Jiangxi Province and provide scientific evidence for conducting malaria surveillance targeting the risk populations and areas.Methods:?The Delphi method was used to establish the risk indicators system of the secondary transmission by imported malaria and obtain the weight of each index.?The malaria cases data of Jiangxi province from 2012 to 2015 were obtained from the National Information Management System for Infectious Diseases Report and Information Management System for Parasitic Diseases Control and Prevention.Descriptive analysis was performed to know the detailed information about primary medical facilities,laboratory testing units,diagnostic methods,and the periods from the onset to first medical visit,first medical visit to reporting and the onset to reporting at different levels of institutions.?The data of malaria prevalence,vector distribution and institutional capacity were collected from 100 counties of Jiangxi Province during 2012-2015.The risk indicators including Transmission Potential Index(TPI),Intervention Capacity Index(ICI)and Malaria Risk Index(MRI)were calculated for each county.The distribution map of potential risk caused by the imported cases was drawn with GIS software.Results:? The risk indicators system of the secondary transmission was established including 3 first-level indices and 10 second-level indices.In the first-level indices,the infection source had the highest weight(1.000).In the second-level indices,the three top weight indices were the number of imported malaria cases(0.979),Anopheles species(0.893),and infected species of the imported cases(0.882).?A total of 207 imported malaria cases were reported during 2012-2015 in Jiangxi,of which 96.62%(200/207)were due to laboratory diagnosis.County-level(29.95%,62/207)and prefecture-level(25.60%,53/207)medical institutions were main primary medical units for malaria detection,while prefecture-level medical institutions(35.27%,73/207)and County-level CDCs(20.29%,42/207)were main laboratory testing units.There was a significant difference in the proportions of different laboratory testing units among year groups(P<0.05).The periods of onset to first medical visit,first medical visit to reporting and onset to reporting were 1d,3d and 5d,respectively.?The top ten counties with highly potential risk indicators were Linchuan district(2.131),Xinzhou district(1.609),Jiujiang county(1.404),Zhanggong district(1.365),Fengcheng city(1.225),Qingshanhu district(1.184),Yudu county(1.171),Dingnan county(1.018),Xunyang district(1.015)and Zhushan district(1.006).High risk areas are mainly distributed in the regions in counties with more floating population and higher historical vectorial capacity.Conclusions:?The secondary transmission risk indicators system was established and applied to the risk assessment of the secondary transmission by imported malaria in Jiangxi province.?The first visit and the laboratory testing of imported malaria cases mainly took place in the prefecture-level medical facilities.?There is to some extent the risk of the secondary transmission by imported malaria in Jiangxi province.The high risk of the secondary transmission is shown in the areas with more floating populations and poor intervention capacity.But the overall risk level is still low based on this study.