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@#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.
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Objective:To observe the difference in drying dampness between Scutellariae Radix and Atractylodis Rhizoma in model rats with spleen-stomach dampness-heat syndrome and clarify their property-efficacy relationship. Method:Sixty-four healthy male SD rats were randomized into the blank group, model group, high-, medium-, and low-dose Scutellariae Radix groups, as well as high-, medium-, and low-dose Atractylodis Rhizoma groups. The rats were exposed to high-fat and high-sugar diet and external dampness-heat environment for 20 days for inducing the spleen-stomach dampness-heat syndrome. The macroscopic manifestations of rats were observed and the morphological changes in stomach and colon were detected under a light microscope after hematoxylin-eosin (HE) staining, followed by the calculation of pathological scores. The serum tumor necrosis factor-<italic>α</italic> (TNF-<italic>α</italic>), interleukin-4 (IL-4), and interferon-<italic>γ</italic> (IFN-<italic>γ</italic>) levels were determined by enzyme-linked immunosorbent assay (ELISA). The protein and mRNA expression levels of aquaporin-4 (AQP4) in the gastric tissue were measured by Western blot and Real-time polymerase chain reaction (Real-time PCR), respectively. Result:Rats in the model group presented with the manifestations of dampness-heat syndrome. The inflammatory reaction in stomach and colon was obvious, and the pathological score was significantly increased (<italic>P</italic><0.01). The serum IFN-<italic>γ</italic>, IL-4, and TNF-<italic>α</italic> levels were elevated (<italic>P</italic><0.05), and so were the AQP4 protein and mRNA expression levels in the gastric tissue except that there was no statistical difference. The clinical symptoms of rats in the medication groups were alleviated. Scutellariae Radix significantly relieved the gastric and colonic inflammation in model rats. Atractylodis Rhizoma inhibited the colonic inflammation in model rats to a certain extent, but it had no obvious effect on gastric inflammation. The pathological score of each Scutellariae Radix group was decreased. In terms of the pathological score of gastric tissue, only the high-dose Scutellariae Radix produced a significant difference (<italic>P</italic><0.01), and the pathological scores of the three Atractylodis Rhizoma groups were not significantly different from that in the model group. As for the pathological score of colonic tissue, all the medication groups except for the low-dose Atractylodis Rhizoma group exhibited a significant difference in comparison with that of the model group (<italic>P</italic><0.01). Scutellariae Radix and Atractylodis Rhizoma at each dose reduced not only the serum IFN-<italic>γ</italic>, IL-4, and TNF-<italic>α</italic> levels (<italic>P</italic><0.05, <italic>P</italic><0.01), but also the AQP4 protein expression in gastric tissue of model rats (<italic>P</italic><0.01). The AQP4 mRNA expression in the gastric tissue of model rats declined in the high- and low-dose Scutellariae Radix groups, while that in the medium-dose Scutellariae Radix group and each Atractylodis Rhizoma group rose without statistical difference. Conclusion:Scutellariae Radix and Atractylodis Rhizoma display a certain property-efficacy relationship in drying dampness of rats with spleen-stomach dampness-heat syndrome. Specifically, the efficacy of drying dampness is related to their cold/heat property, and the resulting outcome of bitter-cold Scutellariae Radix is better than that of bitter-warm Atractylodis Rhizoma.
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Objective To understand the epidemiological characteristics and the influencing factors of Japanese encephalitis (Abbreviated JE) at different periods in Hainan province, and to provide evidence for JE control strategies. Methods Data on JE had been collected since 1952 and related incidence, mortality, fatality rates of JE and the rate of JE vaccination were calculated for four periods: the natural epidemic period (1952-1978), period for inactivated JE vaccine promotion (1979-1986), national immunization program period (1987-1990) and the promotion of live-attenuated JE vaccine period (1991-2007). History on the immunity of JE and data from the monitoring programs on cases and insect vectors were also analyzed. Results The average annual incidence in natural epidemic period was 7.12/100 000, which was also the highest among the 4 periods with the mortality rate as 0.89/100 000. The average annual incidence was 0.11/100 000 which was the lowest while the mortality rate was 0.01/100 000 in the period when live-attenuated JE vaccination was under promotion. Since the establishment of JE surveillance system was set up in Hainan province in 2002, the specimen collection rate of JE reported suspected cases had reached 92.8%, while the incidence of confirmed JE cases fluctuated between 0.05/100 000 and 0.2/100 000. Of the confirmed cases, 86% did not have clear history of JE vaccination. The annual average protective rate reached 95.69% in 2004-2007. The density of insect vectors was high in Hainan province. The infection rate of JE in host animal swine, kept rising from April to October, and in some surveillance points, the rate reached 99.3%. The density of insect vector plotted in trans-curve with the infection of host animals. Conclusion The application of live-attenuated JE vaccine was found to have had significant protective effect on JE in susceptible children. It helped reducing the incidence and controlling the epidemics of JE. It appears feasible to include live-attenuated JE vaccine into the expanded immunization program.
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<p><b>OBJECTIVE</b>To evaluate the development and operation on measles surveillance system.</p><p><b>METHODS</b>To formulate surveillance program, and then establish surveillance system on measles in Hainan province before the case surveillance was conducted. Descriptive epidemiological method was used to analyze the measles cases reported through the notifiable diseases epidemic situation report system and measles surveillance system during 2004 - 2008 in Hainan province.</p><p><b>RESULTS</b>From 2004 to 2008, through surveillance system, 3040 suspected measles cases were reported which was 96.00% higher than that from the notifiable diseases epidemic situation report system. When the measles surveillance system was first established in 2004, the number of cases reported by the surveillance system was less than that from the epidemic report system, however, the sensitivity of the surveillance system had been increasing since 2005. In 2008, the number of suspected cases reported by surveillance system was 19.12 times more than from the epidemic report system. The proportion of confirmed cases in the total suspected cases was decreasing annually, from 90.34% to 4.48%, along with the increase of the sample collection rate, from 22.73% to 99.12%. The proportion of laboratory confirmed cases in the total confirmed cases increased from 7.55% to 86.97%. With suspected cases, the IgM antibody positive rate on measles and rubella were 31.57% and 34.52%, respectively. In Hainan, the epidemic pattern of measles had been sporadic, except for 2006 as there occurred several outbreaks in that year. The of disease incidence had an obvious seasonal peaks, from March to June. Measles mainly attacked children under 15 years of age, accounted for 86.68% of the age group. Children with no immunity or unknown immune history accounted for 85.67%.</p><p><b>CONCLUSION</b>The sensitivity of surveillance system had been increasing annually since it was developed and the incidence had been dropping to its lowest level. These achievements had built a solid foundation for the eventual elimination of measles.</p>