ABSTRACT
@#Abstract: Objective To understand the density changes and seasonal fluctuation of larvae and adults of Aedes albopictus in Hainan Province from 2017 to 2021, and to provide a scientific basis for the prevention and control of dengue fever and other vector-borne diseases in Hainan Province. Methods The Breteau index method was used to monitor the larvae of Aedes mosquitoes, and the breeding sites of all small indoor and outdoor water containers and their larvae was checked and recorded. The adult mosquitoes were monitored by double lamination and light trap. Results A total of 1 962 adult female Aedes albopictus mosquitoes were captured in Hainan Province from 2017 to 2021, accounting for 2.17% of the total captured mosquitoes. There were significant differences in mosquito species composition in different habitats in different years (χ2=312.258, P<0.01). In 2017, the density of mosquitoes in livestock sheds was the highest (9.71 per lamp·night), but the composition ratio of Aedes albopictus was the lowest (1.29%). In 2020, the mosquito density in hospitals was the lowest (2.22 mosquitoes per lamp·night), and in 2019, the proportion of Aedes albopictus in residential areas and hospitals was the highest (3.27% on average).The mosquito density in different habitats was the lowest in 2020. The proportion of Aedes albopictus in residential areas and livestock sheds showed an increasing trend from 2017 to 2021, while the proportion of other habitats showed significant fluctuations. The proportion of Aedes albopictus in hospitals showed an obvious decreasing trend in 2020. From 2017 to 2021, the average mosquito density was 5.97, 4.26, 3.82, 3.39 and 3.68 mosquitoes per lamp·night, respectively, showing a decreasing trend year by year except 2021. Except for 2019, the lure index also showed a decreasing trend, with an average value of 1.5/(hour·net), showing a decreasing trend year by year. From 2017 to 2021, the annual average density of Aedes albopictus in Hainan Province was 0.09 mosquitoes per lamp·night, showing obvious seasonal fluctuation. The Breteau index showed a slow decline from 2017 to 2021, and its annual peak was between June and August, which was 1-2 months later than the peak of adult mosquito density. Conclusions The population density of Aedes albopictus in Hainan shows obvious seasonal characteristics. Mosquito control activities should be carried out according to the seasonal characteristics of mosquitoes to reduce the risk of dengue fever and other infectious diseases.
ABSTRACT
Objective To understand the dynamic of Oncomelania hupensis snail status in Duchang County at north shore of Poyang Lake so as to provide the evidence for formulating the strategy of schistosomiasis control. Methods The data about the snail status in Duchang County from 2005 to 2012 were collected and the change trend of the snail status was analyzed. Re?sults From 2005 to 2012 all the average density of living snails the occurrence rate of frames with living snails the density of infected snails and the area with infected snails showed a trend of sharp decline and stayed at a low level. Compared to 2005 the above 4 indexes in 2008 decreased by 70.06% 90.33% 79.48% and 37.88% respectively and those in 2012 decreased by 99.35% 98.98% 99.33% and 93.84% respectively. The infection rates of snails fluctuated between 0.06%and 0.53%which showed a trend of first decrease and then increase. The snail area maintained at the level of 2 052.5 hm2 since 2007. Con?clusions Most of the indexes of the snail status in Duchang County have decreased to the lowest level in history since 2012 but the snail area is stable and the infection rate of snails shows a fluctuation trend which suggests that the risks of schistosomia?sis transmission still exist and the snail control still should be strengthened.