Changes and correlation of dengue fever epidemic and Aedes albopictus density in Haizhu district, Guangzhou before and after the COVID-19 pandemic

ABSTRACT

To analyze the population density, seasonal fluctuation of Aedes albopictus in Haizhu District, Guangzhou from 2017 to 2021, so as to provide a scientific basis for the monitoring and prevention and control of mosquito vector density of dengue fever. The data of dengue fever cases and Aedes surveillance data in Haizhu District, Guangzhou from 2017 to 2021 were collected, and the data of 2017-2019 and 2020-2021 were grouped to compare and analyze the characteristics of dengue epidemic and the density fluctuation of Aedes mosquitoes. A total of 517 dengue cases were reported in Haizhu District, Guangzhou from 2017 to 2021, of which only 7 cases were reported from 2020 to 2021, and the peak period of reported cases every year was August to November. Before the COVID-19 pandemic, there was a positive correlation between the number of local cases and the number of imported cases(rs=0.63, P<0.05) and BI(rs=0.73, P<0.05). The peak density of Aedes was from May to October, and the differences of mean BI(X~2=1 143.40,P<0.001), MOI(X~2=188.30,P<0.001), and SSI(X~2=4 499.43,P<0.001)before and after the COVID-19 pandemic were statistically significant. In general, before and after the COVID-19 pandemic, the density of Aedes in high-risk areas was higher than that in low-risk areas. After COVID-19 pandemic, the number of reported cases and the density of Aedes in Haizhu District decreased, but the density of Aedes in the high-risk area was still higher than that in low-risk areas, and a certain risk of outbreak still existed, so the government should continue to take more precise measures to strictly prevent dengue epidemic.