Abstract: Objective To understand the population and density of malaria vector in Jiaozuo City for evidences to evaluate the risks in control of malaria vectors and retransmission of imported malaria after malaria elimination. Methods Between 2020 and 2021, seven counties (cities/districts) in Jiaozuo City were selected as malaria transmission vector monitoring sites. All-night mosquito lamp traps and artificial entrapment methods were used to investigate the mosquito population and density. Twenty large and medium-sized water bodies were included as sties for investigating the mosquito breeding using spoon catching method. Results Anopheles sinensis were found in the 7 counties(cities/districts) except in Jiefang district. Totally, 8 116 mosquitoes were captured in 2020. The constituent ratio of Anopheles sinensis was 21.76%, with the highest in Xiuwu County(1 262) and areas in Qinyang City(40.39%). The number of Anopheles sinensis was maximum in indoor environment, and the constituent ratio of Anopheles sinensis was the highest in outdoor surroundings. A total of 802 mosquitoes were captured for density monitoring. The average density was 30.55 mosquitoes captured by one person per hour. Of the 802 mosquitoes, 136 were Anopheles sinensis, with an average density being 5.18 captured by one person per hour. One hundred and twenty-six larvae of Anopheles sinensis were caught in the rice fields, yet they were free in other water bodies. 10 852 mosquitoes were seized in 2021. The constituent ratio of Anopheles sinensis was 1.67%, with the highest in Xiuwu County(179，1.99%), and was higher in indoor environment than in outdoor surroundings. For density monitoring, 3 662 mosquitoes were trapped in 2021, the density was 130.79 mosquitoes captured by one person per hour. One hundred and eight Anopheles sinensis were caught, with an average density being 3.85 captured by one person per hour. Three larvae of Anopheles sinensis were caught in the rice fields, yet no larva was found in other water bodies. Conclusion Anopheles sinensis is the major malaria vector in Jiaozuo City, with wider distribution and density. Retransmission risks associated with imported P. vivax infection still remain in our areas after elimination of malaria. 

Key words: Malaria, Anopheles sinensis, Vector surveillance, Jiaozuo City