关键词: 疟疾, 媒介按蚊, 大理白族自治州

Abstract: Objective To investigate the distribution of malaria vectors Anopheles after the elimination of malaria in 12 counties and cities in Dali Bai autonomous prefecture (Dali prefecture), Yunnan province, China; to assess the local risk of imported malaria retransmission, and to provide a basis for consolidating local achievements of malaria elimination and formulating local technical schemes for preventing imported malaria retransmission after elimination of malaria. Methods The study was conducted from July to September in 2017. According to the altitude, each county (city) was divided into high, middle, and low stratifications, and one natural village from each stratification was selected as the survey site. The all-night light trapping method and half-night human-bait method were used. One barn or human room in the east, west, south, north, and middle of each survey site was selected as an observation point. The all-night light trapping method was used to catch mosquitoes at each survey site for 3 consecutive nights per month, and the half-night human-bait method was used to catch mosquitoes at each low-altitude survey site once a month. Results A total of 13 species of Anopheles mosquitoes were captured, among which An. sinensis was distributed in all these 12 counties and cities; An. minimus was only caught in Yunlong county; An. kunmingensis was distributed in 7 counties and cities, i.e., Xiangyun county, Jianchuan county, Binchuan county, Heqing county, Eryuan county, Weishan county, and Dali city. The results of all-night light trapping method showed that Xiangyun county had the highest density of Anopheles mosquitoes (164.55 mosquitoes/light·night). The results of half-night human-bait method showed that only Jianchuan county and Heqing county had Anopheles mosquitoes caught, and the densities were 0.72 mosquitoes/net·h and 0.06 mosquitoes/net·h, respectively. Conclusion Considering the imported malaria cases in 2018-2020, Dali city is at risk of retransmission of Plasmodium vivax; Yunlong county is potentially at risk of retransmission of multiple malaria; the other 10 counties are all potentially at risk of retransmission of P. vivax. It is suggested that related departments should keep strengthening the team building for malaria control and the surveillance work of malaria vectors Anopheles.

Key words: Malaria, Anopheles vectors, Dali Bai autonomous prefecture