Objective To investigate and analyze the changes in tick density by time, region, host animal, and habitat based on tick surveillance results in Shaoxing, Zhejiang Province, China from 2017 to 2019, so as to provide a basis for developing tick prevention and control measures.Methods At six surveillance sites set in Shaoxing, the parasitic ticks were monitored by animal body surface inspection, and the questing ticks were monitored using the drag-flag method. Descriptive statistical analysis method was used to analyze the data.Results For parasitic ticks, the average tick index in Shaoxing from 2017 to 2019 was 0.53; by month, the highest tick index was 0.78 in September, and the lowest was 0.03 in March; by host animal, goats had the highest tick index (0.77), followed by rural dogs (0.21); and by region, the tick index in Shangyu District was the highest (1.59), while no ticks were detected in Yuecheng District. For questing ticks, the average density was 0.90 ticks/flag·100 m; by month, the highest density was 1.63 ticks/flag·100 m in September, and the lowest density was 0.10 ticks/flag·100 m in March; by habitat, the highest density was 6.57 ticks/flag·100 m on rural sloped grassland, followed by 0.09 ticks/flag·100 m around rural natural villages; and by region, the highest densities were in Shangyu District (5.67 ticks/flag·100 m) and Shengzhou (0.02 ticks/flag·100 m).Conclusions In Shaoxing, the density of questing ticks was highest in rural sloped grassland, and the density of parasitic ticks was highest on goats. In the areas with a high incidence of tick-borne diseases, targeted tick control measures should be taken based on the results of surveillance.

Objective To analyze epidemiological characteristics and outbreak of dengue fever in Yunnan Province, China, so as to provide a scientific basis for formulating effective prevention and control measures. Methods Relevant data on dengue fever cases and outbreaks reported in Yunnan Province during 2013-2022 were collected from the “Infectious Disease Surveillance System” and “Public Health Emergency Management Information System” of “China Disease Control and Prevention Information System”. The concentration method was used to analyze seasonal characteristics. Excel 2007 software was used to sort out the data. MapInfo 7.8 software was used to draw the map. SPSS 26.0 was used to analyze the correlation, and the Chi-square test was used to compare the rate or composition ratio. The descriptive epidemiological method was used to analyze the epidemiological characteristics and outbreak response to dengue fever. Results A total of 16 774 cases of dengue fever were reported in Yunnan Province from 2013 to 2022, including 11 944 local cases, 4 521 overseas imported cases, and 309 domestic imported cases, with an average annual reported incidence of 3.53/100 000. The disease showed a high incidence every other year. The concentration (M) was 0.84, showing strong seasonality. Imported cases mainly occurred from June to October, and local cases mostly from August to November. The male-to-female ratio of imported cases was slightly higher than that of local cases (χ²=37.596, P<0.001). The majority of local cases were 30～<40 years old (20.14%), and the majority of imported cases were 20～<30 years old (27.58%). The local cases were found in 5 border prefectures (cities). The overseas imported cases were mainly from southeast Asian countries and African countries, and Myanmar, Cambodia, and Laos were the main source countries (96.81%). The domestic imported cases were mainly from Xishuangbanna Dai Autonomous Prefecture (85.76%). The majority of cases were farmers, commercial service personnel, cadres/retirees, housekeepers, job-waiting people, and students. Commercial service personnel accounted for the highest proportion in local cases (21.89%), while farmers accounted for the highest proportion in imported cases (39.90%). There was a significant difference in occupational distribution between imported cases and local cases (χ²=1 535.415, P<0.001). A total of 28 dengue fever outbreaks were reported from 2013 to 2022, including 1 major event and 27 general events. The number of reported cases accounted for 83.41% of the total number of cases, and each event involved an average of 499.71 cases. The median time from the onset of the first case to the verification of event occurrence was 7 (5, 9) days, and the median duration of the outbreak was 110 (27, 140) days. Twenty-five outbreaks occurred in villages/communities. Conclusions Dengue fever in Yunnan has obvious seasonal, aggregated, and regional distribution patterns. We need to further strengthen imported case management, disease vector surveillance and control, and the prevention and control of dengue fever in key areas.

Objective To test the mosquito control efficacy of releasing PAB males of Aedes albopictus artificially infected with wPip and naturally infected with wAlbA and wAlbB strains of Wolbachia into communities at high risk for dengue (high mosquito density, high human population density, and high vegetation coverage), so as to provide a scientific basis for field application of Wolbachia-infected incompatible mosquitoes in class-Ⅰ high risk areas for dengue fever in China.Methods A sufficient quantity of artificially reared male PAB Ae. albopictus were released twice a week into the Jinsha Xincheng community of Chancheng District, Foshan, Guangdong Province, China. At the same time, the density of Ae. albopictus at the release site was monitored using both BG-Traps and mosq-ovitraps, and was compared with the monitoring data of the control site during the same period to assess the population suppression efficacy of the release of PAB males. The two-sided Mann-Whitney U test was used to compare the density of trapped adults and average egg hatches between the release and control sites.Results Through 16 releases of male PAB mosquitoes spanning 17 weeks, the mosquito density at the release site was decreased substantially. The adult mosquito density was decreased by up to 93.67%, with an average reduction of 71.62%. The larva density was decreased by up to 89.45%, with an average reduction of 77.15%.Conclusion Wolbachia-based PAB male of Ae. albopictus population suppression can effectively and sustainably control the density of Ae. albopictus in communities at high risk for dengue, greatly reducing the risk of local spread of dengue fever.

Objective To investigate the density distribution and spatiotemporal aggregation of Aedes albopictus in Songjiang District, Shanghai, China, so as to provide a reference for monitoring, early warning, risk analysis, and precise prevention and control of Aedes-borne infectious diseases.Methods Descriptive analyses were performed on Ae. albopictus larvae density data (mosq-ovitrap index, MOI) in 17 sub-districts and towns of Songjiang District of Shanghai from June to October, 2017-2022. ArcGIS 10.8 and SaTScan 10.1.2 softwares were used to conduct spatial autocorrelation analysis and spatiotemporal scanning analysis, respectively.Results In 2017-2022, the density of Ae. albopictus in Songjiang District increased first and then decreased every year, with the peak in July and August. The top three regions by annual average density were Fangsong Sub-district, Sijing Town, and Chedun Town, and residential areas had the highest mosquito density among habitats. Spatial aggregation was found in the density distribution of Ae. albopictus in 2022 (Moran's I=0.139, P=0.047); Ae. albopictus density showed local aggregation in Guangfulin, Yueyang, and Zhongshan sub-districts in 2018, in Guangfulin Sub-district, Yueyang Sub-district, and Dongjing Town in 2021, and in Yueyang, Zhongshan, and Yongfeng sub-districts in 2022; the aggregation hotspots in 2018 were observed in Zhongshan Sub-district and Chedun Town; and the aggregation hotspots in 2022 were observed in Zhongshan Sub-district, Yueyang Sub-district, and Chedun Town. Spatiotemporal scanning analysis indicated a class-Ⅰ gathering area involving Fangsong, Yueyang, Yongfeng, and Zhongshan sub-districts and Chedun Town (log-likelihood ratio was 68.61, relative risk was 2.66, P<0.001).Conclusion The density distribution of Ae. albopictus was gradually aggregating towards central urban areas in Songjiang District from 2017 to 2022, and Fangsong, Yueyang, Yongfeng, and Zhongshan sub-districts and Chedun Town were the main areas of local aggregation.

Objective To investigate the distribution of mosquito vectors in Hainan Province, China from 2020 to 2022, so as to provide common mosquito ecological surveillance data for analyzing the risk of transmission of imported mosquito-borne diseases after the initiation of China (Hainan) Pilot Free Trade Zone operations. Methods In 18 cities (counties) across the province throughout the years, adult mosquitoes were monitored using the light trap method and the double-layered mosquito net method, and larval mosquitoes were monitored using the Breteau index (BI) method. With the use of R 4.3.1 software, one-way analysis of variance (ANOVA) was performed to compare the mean values of different mosquito populations in different years and regions, and if the difference was significant, the least significant difference method was used for further pairwise comparison. Results From 2020 to 2022, a total of 12 240 lamps were set across Hainan Province, and 41 087 female mosquitoes were captured. The density of mosquitoes was 3.36 mosquitoes/light·night. The annual density fluctuated between 1.59 and 4.55 mosquitoes/light·night, and was significantly different in different years (F=4.810, P=0.015). The net trap index for Aedes was 0.90 mosquitoes/net·hour. The annual fluctuated between 0.06 and 1.74 mosquitoes/net·hour, and there was no significant difference in the mean net trap index of different years (F=2.697, P=0.082); The BI for Aedes larvae was 4.13. The annual BI fluctuated between 2.13 and 6.60, and the mean BI showed no significant difference between different years (F=2.969, P=0.065). The mosquito density by the light trap method showed an obvious seasonal pattern, which was higher in summer than in winter; the density of Ae. albopictus also showed obvious seasonality, which was lowest during December to next February, and then increased to high levels during June to August, followed by a downward trend after August. There were significant differences in the mean annual values of adult mosquito density (F=7.758, P<0.001) and BI (F=11.630, P<0.001) between different dry and wet climate zones, but the net trap index showed no significant difference (F=1.977, P=0.113). Conclusions The annual mosquito density, net trap index and BI were all at a low level in Hainan Province from 2020 to 2022, but mosquito density were high in some areas. It is necessary to pay close attention to the mosquito vector density after the closure of the free trade port, and strengthen the surveillance of the vector mosquitoes.

Objective To investigate the species and distribution of mosquitoes in the residential areas of the Yuanjiang River-Red River basin, Yunnan Province, China, and to analyze their species composition and distribution characteristics, so as to provide reference data for the prevention and control of mosquito-borne diseases in this region. Methods During July to August in 2022 and June in 2023, mosquitoes were collected using light traps at night in nine rural residential areas selected from five counties/cities located in the upstream, midstream,and downstream areas of the Yuanjiang River-Red River basin. Excel 2013 software was used for data pooling and analysis. The Berger-Parker index (I) was calculated to determine the dominant mosquito species. The Kruskal-Wallis H test was used to compare the densities of mosquitoes in different regions. Spearman's rank correlation analysis was performed to analyze the correlation between latitude and the richness and density of mosquitoes. Results A total of 76 710 female mosquitoes belonging to 29 species in 7 genera under 2 subfamilies were captured in the two field surveys. Culex tritaeniorhynchus (I=0.73) and Anopheles sinensis (I=0.21) were the dominant mosquito species in the basin. Among all the mosquito species, the density of Cx. tritaeniorhynchus was highest at 430.57 mosquitoes/night·lamp, followed by An. sinensis at 126.79 mosquitoes/night·lamp. There was no significant difference in mosquito density between different regions (H=3.773, P=0.152). With the decrease in latitude from the north to south of the basin, increasing trends were observed for mosquito species richness (r_s=-0.678, P=0.045) and density (r_s=-0.745, P=0.021). Conclusion The densities of Cx. tritaeniorhynchus and An. sinensis are high in the Yuanjiang River-Red River basin,where health departments should strengthen the surveillance of mosquito density and cases of Japanese encephalitis.

Objective To analyze the seasonal fluctuation and distribution in different habitats of Culex pipiens pallens/quinquefasciatus in Changsha, Hunan Province, China from 2017 to 2022, so as to provide a scientific basis for the control of Cx. pipiens pallens/quinquefasciatus and mosquito-borne infectious diseases in Changsha. Methods According to the National Vector Surveillance Program, Cx. pipiens pallens/quinquefasciatus mosquitoes were obtained using the light trap method in urban residential areas, parks, hospitals, residential houses, and pig pens from April to November of 2017 to 2022. The mosquito population density, seasonal fluctuation, and distribution were analyzed. The mosquito density of different years was compared through analysis of variance (ANOVA) with a completely randomized design, and mosquito density in different months and different habitats was analyzed by two-way ANOVA. Results The mean annual density of Cx. pipiens pallens/quinquefasciatus in Changsha from 2017 to 2022 was 17.83 mosquitoes/light·night. Throughout a year,mosquito density showed a bimodal distribution,peaking in May-June and September. Density differed significantly in different months (F=15.921, P<0.001),which was highest in May (38.92 mosquitoes/light·night) and June (40.42 mosquitoes/light·night). The mosquito densities of different habitats were also significantly different (F=36.014,P<0.001),with the highest levels in pig pens (40.06 mosquitoes/light·night) and residential houses (30.23 mosquitoes/light·night). There was interaction between "month" and "habitat" (F=5.563, P<0.001). Conclusions The peak activeity of Cx. pipiens pallens/quinquefasciatus is in May and June, and the density in pig pens and residential house is high. Specific control programs should be development depending on habitat and season, and mosquito control should be strengthened in rural areas in May and June.

Objective To explore a dominance calculation method from biomass, temporal, and spatial dimensions that can provide more real reflection of species dominance.Methods The mosquito surveillance data of Wuxi, Jiangsu Province, China from 2012 to 2021 were analyzed using Excel 2019 software. The Kendall’s W coefficient was used to determine the consistency between the Time-Space index, Berger-Parker index, and McNaughton index. The results of the three calculation methods were compared using non-parametric Kruskal-Wallis H tests.Results The Kendall’s W coefficients for the three dominance calculation methods of all species were all >0.900, with a significant difference between them of Culex tritaeniorhynchus, Aedes albopictus, Anopheles sinensis (all P<0.05). There were no significant differences in the three dominance indices for Cx. pipiens pallens/quinquefasciatus and Ar. subalbatus (χ²=1.157, P=0.561; χ²=4.622, P=0.099). For Cx. tritaeniorhynchus, Ae. albopictus, and An. sinensis, the Time-Space index was all significantly lower than the Berger-Parker index (Z=-2.192, P=0.028; Z=-2.343, P=0.019; Z=-2.041, P=0.041), and for An. sinensis, the McNaughton index was significantly lower than the Berger-Parker index (Z=-2.192, P=0.028).Conclusion The Time-Space index can significantly improve the resolution of distribution heterogeneity of certain species, which can better reflect the true state of relative dominance of species.

Objective To investigate the characteristics of dengue fever outbreaks in four cities/counties of Yunnan Province, China, and to provide a reference for the prevention and control of dengue fever. Methods The data about dengue fever cases reported in Yunnan Province in 2023 were collected from the China Information System for Disease Control and Prevention. The circular distribution method was used to analyze the temporal patterns of dengue fever outbreaks in Gengma Dai and Wa Autonomous County, Jinghong City, Ruili City, and Mengla County. Excel 2010 software was used for data collation, and SPSS 19.0 software was used for data analysis. The rate or constituent ratio was compared using the Chi-square test. The correlation of non-normally distributed continuous data was examined through Spearman correlation analysis. Descriptive epidemiological method was used to describe the characteristics of dengue fever outbreaks in the four cities/counties. Results A total of 13 748 cases of dengue fever were reported in Yunnan Province in 2023, with a reported incidence rate of 29.42/100 000. The four cities/counties reported a total of 10 012 cases of dengue fever, accounting for 72.83% (10 012/13 748) of the total number in the province. The peak period was from June 15 to November 11, and the peak day was August 30. The temporal distributions of the imported cases, local cases, and exported cases in the four cities/counties were generally consistent, and they were correlated in different months (r_{simported-local}=0.901, P=0.006; r_{slocal-exported}=0.893, P=0.007; r_{simported-exported}=0.793, P=0.033). In terms of the reported cases distribution, the top five occupations were farmers, homemakers and the unemployed, business employees, freelancers, and students, accounting for 31.25% (2 795/8 945), 16.88% (1 510/8 945), 14.21% (1 271/8 945), 10.90% (975/8 945), and 8.09% (724/8 945), respectively. By age distribution, the group of 20 to <70 years accounted for 80.00% (7 818/9 772), with the highest reported incidence rate in the group of 70 to <80 years (1 244.41/100 000) and lowest in the group of <10 years (306.55/100 000). There was an increasing trend in the reported incidence rate with age (χ²_trend=985.310, P<0.001). By regional distribution, the cases were mainly concentrated in ports or urban townships densely populated and with large numbers of floating people, which were more distributed in the border areas and scattered in the inland and suburban townships. The number of local cases reported in national port townships was largest, with an incidence rate of 1 341.09/100 000, while the lowest incidence rate was 250.60/100 000 in townships without ports or local channels. As the opening level increased, the incidence rate of local cases reported in each township tended to increase (χ²_trend=4 610.937, P<0.001). The incidence rate of each township was positively correlated with the local population density (r_s=0.446, P=0.006). Conclusions In the four cities/counties of Yunnan Province, dengue fever cases are mainly clustered in ports or urban townships, and show specific distribution patterns by region, population, and time. The focus should be on densely populated urban areas and port townships with large floating populations near the border, and high attention should be paid to the long-distance export of infectious sources and vectors to low-risk areas.

Objective To investigate the density, species composition, and seasonal fluctuations of mosquitoes in human settlements and surrounding environments in Liaoning Province, China from 2020 to 2022, so as to provide a basis for effective prevention and control of mosquito-borne diseases.Methods From May to October of 2020 to 2022, mosquitoes were monitored using the light trap method in residential areas, parks, hospitals, rural households, and livestock sheds in 14 cities. The surveillance data were analyzed using Excel 2016, ArcGIS 10.7, and SPSS 27.0 softwares. The Chi-square test was used to compare the composition ratio of mosquito species. The Levene's test was used to assess the homogeneity of variance of mosquito densities by year and by habitat. The Friedman test for multiple paired samples was used to compare their differences between groups.Results From 2020 to 2022, a total of 4 239 mosquito lamps were deployed in Liaoning Province, capturing 238 193 female mosquitoes. Anopheles sinensis was the dominant species, accounting for 40.22 % of the total mosquitoes, followed by Culex pipiens pallens and Aedes dorsalis, accounting for 22.11 % and 20.25 %, respectively. The total mosquito density was 56.19 mosquitoes/light·night. The mosquito densities of 2020-2022 were 45.67, 42.72, and 80.84 mosquitoes/light·night, respectively. The mosquito density of livestock sheds was the highest, reaching 206.48 mosquitoes/light·night, followed by rural households with a density of 17.04 mosquitoes/light·night, and the lowest was in residential areas with a density of 5.25 mosquitoes/light·night. The mosquito density of livestock sheds was highest for all species except for Ae. albopictus, which only appeared in residential areas, parks, and hospitals. Among the surveillance points in the province, Anshan had the highest mosquito density of 215.27 mosquitoes/light·night, followed by Yingkou with 157.28 mosquitoes/light·night, and Dalian had the lowest density of 3.11 mosquitoes/light·night. The overall seasonal fluctuation in mosquito density showed a single-peak curve, reaching the highest in early August with a density of 179.48 mosquitoes/light·night. The seasonality of mosquito density differed significantly between different years (χ²=36.440, P<0.001) and between different habitats (χ²=26.272, P<0.001).ConclusionsAn. sinensis, Cx. pipiens pallens, and Ae. dorsalis are the dominant species in human settlements and surrounding environments in Liaoning Province. Mosquito density in rural habitats is high, especially in livestock sheds, which are major breeding sites and need strengthened mosquito control. Comprehensive prevention and control measures should be taken before the peak period of mosquito activity from June to August, to reduce mosquito density and the risk of mosquito-borne diseases.

Objective To investigate the density of the dengue vector Aedes larvae and its change over time in Jiangxi Province, China, so as to provide a theoretical basis for the prevention and control of dengue fever.Methods During May to October in 2015-2022, the density of Aedes larvae was monitored using the Breteau index (BI) method at 13 dengue vector surveillance sites in the province. R 4.3.1 software was used for data analysis. The container index (CI) for different container types was compared using the t test. The correlation between CI and house index (HI) and BI was determined through Pearson correlation analysis. The changes in annual average CI for different container types were analyzed using the Cochran-Armitage test for trend. Joinpoint 5.0.2 software was used to test the trend in annual average BI.Results From 2015 to 2022, the BI of Ae. albopictus larvae ranged from 5.88 to 15.36, CI ranged from 6.84 % to 17.10 %, and HI ranged from 4.73 % to 10.69 %. Except for a slight increase in 2016, the annual average BI in Jiangxi Province showed a downward trend as a whole. The CI of temporary containers showed a downward trend (Z=-18.514, P<0.001), and the overall level was higher than that of permanent containers (t=-2.739, P=0.029). The seasonal fluctuation of Aedes larvaeshowed a unimodal distribution, in which BI mainly peaked during May to June and then declined in every year. CI and HI showed basically the same changing trends as BI, and the correlation coefficients were 0.827 (P<0.001) and 0.916 (P<0.001), respectively. The annual average BI in northern and southern Jiangxi Province were higher than that in central Jiangxi Province. The monthly average BI was >10 from May to August and 5-10 from September to October. The number of surveillance sites with BI exceeding the transmission threshold was largest in 2019, and the number of surveillance sites with BI exceeding the transmission threshold was largest in June.Conclusions The overall density of Ae. albopictus in Jiangxi Province shows a downward trend, but there is still a risk of local transmission of dengue fever. It is necessary to strengthen integrated control against Ae. albopictus to reduce the risk of dengue outbreaks.

Objective To establish a multiplex real-time fluorescent quantitative reverse transcription polymerase chain reaction (multiplex real-time qRT-PCR) method for rapid detection of nucleic acids of Alongshan virus (ALSV) and Songling virus (SGLV). Methods Specific primers and TaqMan probes were designed for the conserved regions of the NS 3 gene of ALSV and the S gene of SGLV. A multiplex real-time qRT-PCR method was established for the two viruses, and the specificity, sensitivity, and repeatability of the method were evaluated. Tick specimens were used to verify the method. Results The detection method had no cross-reactivity with six other arboviruses, such as tick-borne encephalitis virus, with a sensitivity up to 1×10¹ copies/μl, and the coefficient of variation of cycle threshold for repeatability testing was less than 2.00%. Through this method, two groups of ALSV-positive specimens and one group of SGLV-positive specimens were detected from 30 groups of tick specimens collected from Heilongjiang, China in 2019. This method was verified to be 100% consistent with the general PCR method in terms of test results. Conclusion In this study, a highly sensitive and highly specific multiplex real-time qRT-PCR method for rapid detection of ALSV and SGLV has been successfully established.

Objective To investigate the rodent species composition, density, and seasonality in different habitats based on the rodent surveillance program in Nanchang, China, so as to provide a basis for scientifically formulating rodent control strategies in Nanchang. Methods Three types of surveillance habitats including urban residential area, rural natural village, and special industry were chosen from 2017 to 2022. Rodent density was investigated by the night snap-trapping method. Descriptive methods were used to perform a statistical analysis of rodent species composition and seasonal variation of rodent density in three different habitats in Nanchang. With SPSS 26.0 and Excel 2021 softwares, descriptive methods were used to perform a statistical analysis of surveillance data, and the Chi-square test was used for comparison of rodent density across different years and habitats. Results A total of 104 121 effective traps were placed in Nanchang from 2017 to 2022, and 548 rodents were captured, with an average rodent density of 0.53%. The overall rodent density in the six years was statistically significant (χ²=34.857, P<0.001). A bimodal distribution with seasonal variation was found in the overall rodent density, the annual density of three dominant rodent species (Rattus norvegicus, Mus musculus, and R. tanezumi), and the rodent density in residential areas and special industry habitats, while the rodent density in rural natural village habitats showed a unimodal trend, with the peak in July. The rodent density in rural natural villages (1.56%) was significantly higher than that in special industries (0.45%) and than that in urban residential areas (0.30%) (χ²=304.340, P<0.001). The dominant rodent species in urban residential areas and rural natural village habitats were R. norvegicus and R. tanezumi, while M. musculus predominated in special industry habitats (47.47%). The composition ratio of R. norvegicus in special industry and rural natural village habitats was decreasing year by year; the composition ratio of R. tanezumi in urban residential areas showed a decrease after increasing, while it was generally increasing in special industry and rural natural village habitats; the composition ratio of M. musculus in three different habitats showed an overall increasing trend. Conclusions The rodent density varies greatly in Nanchang from 2017 to 2022. The rodent density showed a bimodal distribution with seasonal changes and was high in rural areas. Specific control measures should be taken according to the changes in rodent species in different habitats to reduce the rodent density and the risk of rodent-borne diseases.

Objective To investigate the density and seasonality of the dengue vector Aedes populations in Henan Province, China, so as to provide a scientific basis for the risk assessment, monitoring, early-warning, and control of dengue fever.Methods From May to October of 2019 to 2022, Aedes vectors were monitored using the Breteau index (BI) method at 14 surveillance sites of Henan Province. Excel 2010 software was used to pool data, determine risk levels, and calculate the seasonal index. SPSS 25.0 software was used to perform the t-test and analysis of variance to compare the BI of different years and regions.Results The BI of Aedes mosquitoes from 2019 to 2022 were 15.31, 14.27, 11.34, and 12.32, respectively. The peaks occurred in July and August. Among 330 monitoring tasks over the four years, a regional spread risk was indicated in 85 (25.76%), an outbreak risk indicated in 70 (21.21%), a transmission risk indicated in 77 (23.33%), and no risk indicated in 98 (29.70%). The proportion of areas reaching a regional spread risk in southern Henan Province was higher than that in the northern part and along the Yellow River. The BI results of 2020, 2021, and 2022 were not significantly different from that of 2019 (all P>0.05). The BI showed no significant difference between regions (all P>0.05).Conclusions The density of Aedes mosquitoes is high in Henan Province, and there is a potential risk of dengue transmission in the peak season of Aedes for most surveillance sites. The number of imported dengue cases is expected to increase substantially in the future, highlighting the need for close attention to domestic and international dengue changes and emergency response and preparedness.

Objective To construct the three-dimensional theoretical model of Hq001 protein encoded by a novel gene, Hq001, cloned from a salivary gland cDNA library of Haemaphysalis qinghaiensis, and to evaluate its relationship with tick-derived Kunitz-type anticoagulant proteins.Methods The recombinant plasmid pET-30a-Hq001 was constructed and transformed into Escherichia coli BL21 (DE3) for the expression of Hq001 protein. AlphaFold v2 software was used to predict the tertiary structure of Hq001 amino acid sequence with the signal peptide removed, to obtain a three-dimensional (3D) theoretical model. The 3D theoretical model was optimized through molecular dynamics simulation using the open-source software GROMACS v2023 and evaluated using ANOLEA and MolProbity.Results The recombinant plasmid pET30a-Hq001 was expressed as inclusion bodies in E. coli BL21. Sequence alignment and structure modeling results showed that Hq001 protein had typical double Kunitz-BPTI domains, with a similar sequence and structure to four Kunitz-BPTI-type anticoagulant proteins, such as Bikunin, Boophilin, Ornithodorin, and Ixolaris. Following 1 ns molecular dynamics (MD) simulation optimization, the root mean square deviation (RMSD) of the theoretical model attained stability at approximately 3 Å, indicative of convergence to a steady-state conformational ensemble. Concurrently, the most energetically favorable structure within this ensemble, exhibiting a total energy of -207 166 400 kJ/mol, was identified and designated as the final model.Conclusion Hq001 protein has conserved Kunitz-BPTI domains that resemble Boophilin from Rhipicephalus microplus in sequence and structure, indicating that Hq001 protein may have similar structure and function to some known Kunitz-type serine protease inhibitors.

Objective To understand the composition of main vector species in Zibo City in 2022, master its density and seasonal fluctuation, so as to provide scientific basis for vector biological control in Zibo City. Methods Four vectors of mosquitoes, flies, mice and cockroaches were monitored in Zibo City.Mosquito surveillance was carried out by the mosquito lamp trapping method and the Breteau index (BI) method. Cage trapping method was used to monitor flies. The night snap trapping method was used outdoors for rodent surveillance.The method of sticky trapping was used for cockroach surveillance. The difference of species composition in different habitats was determined by Chi-square test or Fisher’s exact probability method. Results In 2022, the average density of adult mosquitoes was 11.81 mosquitoes/light·night, and the highest density was 32.51 mosquitoes/light·night in August; the dominant species was Culex pipiens pallens; As for the larvae, BI were all>10.00 in July and August, and >20.00 in September. The average density of flies was 12.51 flies/cage, and the density reached the peak of 66.98 flies/cage in July; Musca sorbens was the dominant species. In 2022, the average density of rodents was 1.15%, with the peak of rodent activity in September, and the dominant rodent species was Rattus norvegicus. In 2022, the average density index of cockroaches in the city was 3.15 cockroaches/sheet, with the peak occurring in September, and Blattella germanica was the dominant species. The composition ratio of mosquitoes, flies and mice in different habitats was different, and the difference was statistically significant (χ²=3 160.149, 1 029.005, 33.394, all P<0.001). Conclusion The main disease vectors in Zibo city were Cx. pipiens pallens, M. sorbens, R. norvegicus and B. germanica. with high densities during July to September in summer. Appropriate measures should be taken to control the density of the vectors to prevent the spread of vector-borne diseases.

Objective To investigate the general situation of human plague in Inner Mongolia Autonomous Region (Inner Mongolia) and to grasp the dynamics and trend of the epidemic, so as to provide a basis for the prevention and control of the plague. Methods The descriptive epidemiological method was applied for the analysis of the data of human plague cases in Inner Mongolia from 1950 to 2021. Chi-square test was used for comparison of counting data. Results From 1950 to 2021, 271 cases of plague were reported in Inner Mongolia, with 130 deaths (case fatality rate: 47.97%). The cases were mainly distributed in 88 epidemic foci in 26 banners (counties and districts) of 8 leagues (cities), i.e., Tongliao, Chifeng, Xing’an League, Xilin Gol League, Ordos, Bayannur, Ulanqab, and Baotou. The plague peaked from July to August, during which 20 outbreaks were observed. The case fatality rates of plague in the natural plague foci of Spermophilus dauricus and Meriones unguiculatus were 51.84% and 32.00%, respectively, with no significant differences between the two (χ²=3.571, P=0.059). Conclusion Human plague in Inner Mongolia has a wide range of transmission and a high case fatality rate, mainly occures in the S. dauricus plague foci and M. unguiculatus plague foci. In the prevention and control of plague in Inner Mongolia, should strengthen innovative research, monitoring and early warning, and timely disposal and control of animal plague to avoid human infection.

Objective To investigate the species composition, density, and seasonal fluctuation of mosquitoes in Yancheng, Jiangsu Province, China, so as to provide a scientific basis for developing effective mosquito control measures and forecasting and early warning of mosquito-borne diseases.Methods Mosquito density was monitored by using the lamp trapping method in five types of habitats (urban residential areas, parks, hospitals, farmers’ houses, and livestock sheds) in Yancheng. The species composition, population density, and seasonal fluctuation of mosquitoes were analyzed. With SPSS 20.0 software, the Chi-square test was performed on the mosquito species composition ratios of different years and different habitats, analysis of variance was performed for different years, different species, and different habitats of mosquito densities, and trend analysis was performed for different years and different species of mosquito densities.Results From 2016 to 2023, a total of 132 432 female mosquitoes were caught in Yancheng, with an average density of 13.59 mosquitoes/light·night. Culex pipiens pallens/quinquefasciatus, Anopheles sinensis, and Cx. tritaeniorhynchus were the top three mosquito species, accounting for 68.62%, 13.95%, and 12.09% of the total catches, respectively. There was a significant difference in the composition of mosquito species between different years (χ²=9 026.399, P<0.001). Mosquito density and trend changes differed significantly in different mosquito species (both P<0.001). By habitat, the highest mosquito density was in livestock sheds (28.37 mosquitoes/light·night), while the lowest mosquito density was in hospitals (7.84 mosquitoes/light·night), with significant differences in the species composition ratio and density of mosquitoes between habitats (both P<0.001). Seasonal fluctuations in mosquito density showed unimodal distributions for all habitats and for all species, peaking during June and September.Conclusions Cx. pipiens pallens/quinquefasciatus, An. sinensis, and Cx. tritaeniorhynchus are the dominant species in Yancheng. Livestock sheds and farmers’ houses are the key places and June to September is the key time for mosquito control. Specific mosquito control measures should be taken based on the population distribution, density change, and seasonal fluctuation of mosquitoes.