Analysis of mosquito vector surveillance and spatiotemporal distribution of Anopheles populations in Jiujiang from 2022 to 2024

LI Youlong; LIAO Lv

doi:10.19821/j.1671-2781.2025.06.018

Abstract：Objective To understand the spatiotemporal distribution of the population and density of malaria vectors after malaria elimination in Jiujiang,so as to provide a reference basis for the risk assessment of re-transmission of imported malaria.Methods From 2022 to 2024,4 to 5 different counties(cities,districts)were selected every year.Mosquito vector monitoring was carried out using the all-night light trapping method from June to October.All counties(cities,districts)in the city were covered over a period of 3 years,and the spatiotemporal distribution of Anopheles mosquito populations was analyzed.Results From 2022 to 2024,a total of 13894 mosquitoes were captured at 13 monitoring sites,including 797 An.sinensis,12593 Culex mosquitoes,and 504 Aedes albopictus.The average density of An.sinensis was 3.72 mosquitoes/(light·night).The density of An.sinensis was the highest in the first ten days of June[6.00 mosquitoes/(light·night)]and the lowest in the second ten days of October[1.00 mosquitoes/(light·night)].Among the 13 monitored counties(cities,districts),the average density of An.sinensis was the highest in Yongxiu County and Pengze County[15.05 mosquitoes/(light·night)and 9.63 mosquitoes/(light·night)],and the lowest in Xunyang District[0.90 mosquitoes/(light·night)].The difference was statistically significant(F=5.641,P＜0.001).Among 3 habitats,the density of An.sinensis was the highest in livestock sheds[24.8 mosquitoes/(light·night)],followed by breeding grounds[3.16 mosquitoes/(light·night)],and the lowest in human settlements[1.96 mosquitoes/(light·night)].The difference was statistically significant(F=63.598,P＜0.001).Conclusion The distribution of mosquito populations in Jiujiang was mainly Culex mosquitoes,followed by An.sinensis.The average density of An.sinensis was relatively high in counties such as Yongxiu County and Pengze County.In recent years,the number of imported malaria cases in Jiujiang has significantly increased,and the proportion of vivax malaria cases has also risen.It is necessary to strengthen the monitoring of malaria vectors,take effective vector control measures to reduce the risk of transmission to prevent the secondary cases of malaria importation.