Abstract: Objective To analyze the epidemiological characteristics of malaria from 2003 to 2020 and seasonal growth and decline of malaria vectors in Qixia district from 2009 to 2020,so as to provide a basis for formulating scientific control strategies. Methods The data,including the malaria cases and annual malaria blood test findings reported from infectious disease information management system in Qixia District from 2003 to 2020,and the data generated from exposure questionnaires for epidemiological studies as well as those from mosquito vector surveillance during 2009 and 2020,were initially collected and statistically interpreted. Results Totally,51 cases of malaria were reported in Qixia District from 2003 to 2020,with an average annual incidence rate of 0. 44 per 100 000 population. Of reported cases,infection with Plasmodium vivax,  Plasmodium falciparum and Plasmodium ovale accounted for 68. 63% (35 / 51),15. 69% (8 / 51) and 5. 88% (3 /51),respectively,and another cases were unspecified(9. 80%,5 / 51) . Local infections and imported cases accounted respectively for 23. 53% (12 / 51) and 76. 47% (39 / 51). One local infection was reported in 2011. From 2009 to 2020,85,  Anopheles sinensis were captured,and no other species of Anopheles were captured,The density of Anopheles sinensis tended to decline. No Anopheles sinensis  was captured after 2016. Conclusion Although Qixia District passed the provincial evaluation of malaria elimination in 2015,yet imported case still occurs. The findings suggest that the situation of malaria prevention and control still remains serious,and it is necessary to further strengthen the surveillance and control of imported malaria epidemics.

Key words: Malaria, Epidemiological characteristics, Surveillance, Qixia District