Objective To formulate a catalogue of alien vectors and pathogenic organisms for early warning and effective prevention of alien species invasion. Methods The authors searched literature, online databases, and published catalogues for alien vectors and pathogens that can seriously threaten the health of human and animals and agricultural and ecological security. They were evaluated for the risk of invasion to China by using a suitable habitat prediction model and a comprehensive evaluation system of multiple indicators. Candidate species with the potential of invasion were included in this catalogue. Results A total of 304 alien species were screened out and listed in this catalogue for China, including 69 vectors and 235 pathogenic organisms. Among them, 275 species (47 vectors and 228 pathogens) had high probability of invading China. Conclusion This catalogue can be used as an early warning directory to prevent alien vectors and pathogenic organisms from invading China, which provides a reference for relevant departments to formulate preventive management strategies and measures.

In 2021, the national surveillance of rodent-borne pathogens of disease vectors had been started up, and a total of 123 prefectures were selected as national surveillance sites. Sampling was completed at 95 surveillance sites. A total of 17 910 rodent specimens were collected, and 16 891 of them were tested. The completion rate of pathogen detection was 94.31%. The overall infection rate of eight monitored rodent-borne pathogens around China was 2.43% (407/16 716) for Hantavirus, 0.02% (4/16 154) for Dabie bandavirus (i.e., severe fever with thrombocytopenia syndrome virus), 5.75% (624/10 850) for Leptospira interrogans, 0.11% (5/4 470) for Rickettsia mooseri, 0.05% (5/10 790) for Orientia tsutsugamushi, 2.39% (75/3 136) for Bartonella, and 0.04% (2/5 075) for Anaplasma phagocytophilum. Francisella tularensis was not detected. More than ten species of rodents were found to be infected with different pathogens in 18 provinces across China. The infection rates of pathogens in rodents in southern regions were relatively high, and the positive rates of pathogens carried by various rodents differed. Rattus norvegicus and Apodemus agrarius were the species in which the most pathogens were detected.

Objective: To select chemical substances with attractive effects on Aedes albopictus for on-field assessment, and to explore the preference of Ae. albopictus to six human odors. Methods: Under laboratory conditions, six chemical substances (1-octen-3-ol, lactic acid, myristic acid, ammonia, acetone, and ethyl acetate) were separately tested for their individual attracting effects on female Ae. albopictus at concentrations of 0.1, 1.0, and 10.0 mg/ml. The six substances were mixed in pairs (1∶1) at certain concentrations, and then the pairs were tested for attracting effects on female Ae. albopictus. The pair with good attractive effects was combined with lactic acid for testing. The attractant combination selected by laboratory experiments was tested for attractive action for Ae. albopictus in the field. The attracting effects of the substances or combinations on Ae. albopictus were compared using the t test and one-way analysis of variance. Results: Ae. albopictus mosquitoes were attracted to 1-octen-3-ol at 0.1, 1.0, and 10.0 mg/ml, myristic acid at 1.0 and 10.0 mg/ml, and ethyl acetate at 0.1 mg/ml, but not to the other three substances at any concentration. The pairs of 1-octen-3-ol+myristic acid, lactic acid+myristic acid, and lactic acid+1-octen-3-ol statistically attracted Ae. albopictus compared with the control group (t=8.102, P=0.001; t=4.696, P=0.009; t=5.127, P=0.007). The combination of lactic acid+1-octen-3-ol+myristic acid statistically attracted Ae. albopictus compared with the control group (F=86.841, P < 0.001). Field testing showed significant differences in the attracting effect between lactic acid+1-octen-3-ol+myristic acid and the control (day 1: t=7.462, P=0.014; day 2: t=20.500, P < 0.001; day3: t=9.383, P=0.001). Conclusion: The combination of lactic acid, 1-octen-3-ol, and myristic acid has attractive action for Ae. albopictus, which should be further researched in the field.

In 2022, the Winter Olympic Games was first held in Beijing, China. To ensure that the key areas of the Winter Olympic Games were not affected by vectors and to minimize the risk of vector-borne diseases, the density of vectors in the key areas of the Winter Olympic Games and the cities where they are located should be effectively controlled. This paper focuses on the vector control strategy and working mechanism during Beijing 2022 Winter Olympic Games, and discusses the control model, risk assessment, inter-sectoral coordination, publicity and training, hazard monitoring, control technology, supervision and inspection, and emergency response with Main Media Center as an example. The vector density was effectively controlled during the Winter Olympic Games, no plague and other vector-borne diseases occurred, and there were no incidents of vector-borne hazards. The vector control model, technical measures, and working mechanism formed during the Beijing 2008 Summer Olympic Games were verified and deepened in the Beijing 2022 Winter Olympic Games, which can be used as a guidance for vector control in similar large-scale activities in the future.

Rodents are not only causing massive damage to human production and life, but they also can pose a great threat to human life and health as they carry pathogens. Controlling the rodent population can reduce rodent infestation and effectively prevent rodent-borne diseases. This review demonstrates the relationship between biological, soil, meteorological, human activities and rodents, and clarifies the influence of environmental factors, human activities on rodents, which provides references for effective control of rodent infestation and scientific prevention and control of rodent-borne disease epidemics.

Objective By simulating low temperature, the parameters of the life table of Aedes aegypti mosquitoes at various developmental stages were studied to understand their population dynamics. Methods Laboratory Ae. aegypti from Danzhou city, Hainan province, China were reared at low temperature, and the development time and survival in all life stages and the oviposition of Ae. aegypti were recorded. The survival rate in all life stages was calculated, and the population dynamics was obtained by drawing a life table. Results At 17 °C, the hatching rate, pupation rate, eclosion rate, and maturation rate of Ae. aegypti were (14.83±1.53)%, (85.73±3.92)%, (96.11±5.71)%, and (13.43±0.90)%. The pre-adult development time of female and male Ae. aegypti was (18.17±0.67) and (17.82±0.36) d, respectively. The development time of the 1st and 4th instar larvae was longer than that of the 2nd and 3rd instar larvae, and the development time of the 4th instar larvae was the longest with (5.43±0.93) d. The adult sex ratio (female: male) was 0.43±0.03; the net productivity was 41.13±0.40; the intrinsic growth rate was 0.11±0.01; the generation span was (32.66±3.23) d; the finite rate of increase was (1.12±0.01)/d. The proportion of stable age was (88.11±1.97)% in the larval stage and (11.89±1.97)% in the adult stage. The proportion of stable age over 11 d for adult mosquitoes was (21.32±2.42)% and (78.68±2.42)% with stable age less than 11 d. The instantaneous birth rate was 0.13±0.01, and the instantaneous death rate was 0.02±0.00. Conclusion Ae. aegypti can complete its life cycle at 17 °C. The egg hatching rate is low, indicating that the egg stage may be a critical stage affecting the development of Ae. aegypti at low temperature, and it may be the key impact factor which limits spreading toward lower temperature areas for Ae. aegypti. At 17 °C, Ae. aegypti mosquito has low activity capacity, prolongs the development time of each stage. The longer adult stage may increase the chance of virus infection and transmission. The vector efficiency should be evaluated in combination with growth potential, activity, and biting ability

Objective To investigate the weight of spleen and the histopathological changes of main organs caused by natural infection of Yersinia pestis in Marmota himalayana (marmot), and to reveal the pathogenic characteristics of plague. Methods The ratio of spleen weight to body weight of living marmots and self-dead marmots obtained from 2020 to 2021 was analyzed. The liver, lung, and spleen of normal marmots and self-dead marmots infected with Y. pestis were collected to make pathological sections for observing histopathological changes. Results The ratio of spleen weight to body weight of self-dead marmots infected with Y. pestis was statistically greater than that of marmots not infected with Y. pestis ( χ ²=33.144, P<0.001). In the liver, lung, and spleen of self-dead marmots infected with Y. pestis, there were cell morphology destruction, inflammatory cell infiltration, vasodilation, and other inflammatory lesions, and vascular injury of the spleen and changes in the red pulp and white pulp were more significant. Conclusion Y. pestis can cause serious inflammatory reaction in marmots, and the pathological changes of the spleen are of more significance for study of the pathogenic process and mechanism of Y. pestis.

Objective To analyze the ecological monitoring data of Aedes vector in Wuhan, China, 2018-2021, and to provide a scientific basis for effective prevention and control of dengue fever. Methods The Breteau index (BI) and double layered mosquito net methods were used for ecological monitoring of Aedes larvae and adults, respectively. All data were collected by Excel 2010 and statistically analyzed by SPSS 20.0 software. Differences in BI at different time points were analyzed by Chi-square test, and differences in net trap index between different habitats at different time points by analysis of variance or Kruskal-Wallis test; the risk of dengue fever transmission was assessed. Results In 2018-2021, the mean BI was 4.50, and the net trap index was 2.44 mosquitoes/net·h. The density index of Aedes fell to the lowest level in 2019 and showed an upward trend in 2020-2021. Meanwhile, the net trap index in residential areas was higher than that in waste tire stacking sites ( H=29.468, P<0.001). The seasonal fluctuation was not completely consistent in different years; the peak BI value was observed from June to August, and the peak net trap index was observed in July and August. In 2018-2021, 64.52% (20/31) of the monitored months presented a risk of dengue fever transmission, and the BI value reached the risk threshold of dengue fever outbreak in July and August in 2021. Conclusion The fluctuation trend of vector Aedes mosquito density is on the rise in Wuhan, and the risk of dengue fever transmission has increased. Aedes vector control measures should be strengthened and improved.

Objective To determine and evaluate the effect of the BG-home mosquito trap for Aedes albopictus, Ae. aegypti, and Culex pipiens quinquefasciatus by laboratory simulation experiments. Methods In a standard glass test room of 28 m ³ in volume, mosquito trapping experiments were performed using BG-home, in the presence or absence of blue light, in combination with each of the attractants BG-homescent, BG-sweetscent, and Yousida (Qianyiduo Co., Ltd., Foshan, China) or no attractant. After 24 hours, we counted the number of captured mosquitoes in the experimental groups and the number of dead mosquito in the blank control group. The capture rate was corrected using the Abbott formula to evaluate the trapping effect. Results The mean capture rates of Ae. albopictus, Ae. aegypti, and Cx. pipiens quinquefasciatus were: 94.00%, 93.33%, and 81.27%, respectively, by BG-homescent with blue light; 90.97%, 90.00%, and 75.67%, respectively, by BG-homescent without blue light; 86.53%, 80.67%, and 70.57%, respectively, by BG-sweetscent with blue light; 83.50%, 76.67%, and 67.00%, respectively, by BG-sweetscent without blue light; 88.47%, 66.00%, and 59.67%, respectively, by Yousida with blue light; 84.75%, 63.33%, and 52.33%, respectively, by Yousida without blue light; 38.00%, 22.67%, and 62.33%, respectively, by attractant-free BG-home with blue light; 35.33%, 20.00%, and 22.33%, respectively, by attractant-free BG-home without blue light. Conclusion With the above three attractants, BG-home had the best trapping effect for Ae. albopictus, followed by Ae. aegypti. Blue light significantly enhanced its trapping effect for Cx. pipiens quinquefasciatus without the use of attractants. BG-home combined with attractants shows a good trapping effect for common mosquitoes, especially Aedes species, which can be used for mosquito surveillance and control in dengue prevention and control.

Objective To monitor the small mammal species in the four port areas of Zhongshan port (Zhongshan, Shenwan, Xiaolan, and Huangpu port areas) in China, and to investigate the parasites and natural pathogens carried by the small mammals. Methods From May 2020 to May 2022, small mammals were captured by night trapping with cages in the four port areas of Zhongshan port. Ectoparasites were collected from the small mammals, followed by nucleic acid extraction. The small mammals’ liver, spleen, lung, and kidney were harvested for nucleic acid extraction. The small mammals and ectoparasites were identified using the cytochrome c oxidase subunit Ⅰ gene, with the primers Batl5310/R6036R and LCO1490/HCO2198 for amplification, respectively. According to the standards for small mammal pathogen detection at frontier ports, the captured small mammals were examined for Yersinia pestis, hantavirus, pathogenic Leptospira, Bartonella, and Francisella tularensis. The Chi-square test was used to analyze the distribution of small mammals in the four port areas and the status of ectoparasite infestation and natural pathogen infection. Results A total of 1 630 trap-times were set in the four port areas of Zhongshan port, and 48 small mammals were captured. The average density was 2.94%. Five small mammals were caught in Zhongshan port area, 24 in Shenwan port area, 7 in Xiaolan port area, and 12 in Huangpu port area, with average densities of 1.23%, 5.88%, 1.73%, and 2.93%, respectively. A total of 34 ectoparasites were obtained, including 17 sucking lice, 12 mites, 4 fleas, and 1 tick. The small mammals’ louse, mite, flea, and tick infestation rates were 10.42%, 12.50%, 6.25%, and 2.08%, respectively. There were no significant difference in the four kinds of ectoparasite infestation rates of small mammals among the four ports (all P>0.05). Ten small mammals of three species were positive for Bartonella, with an overall positive rate of 20.83%; the positive rate was 50.00% in Huangpu port area, 16.67% in Shenwan port area, and zero in Zhongshan and Xiaolan port areas; 4, 1 and 5 mice were detected positive for Bartonella from 8 Rattus tanezumi, 3 R. norvegicus, and 37 Suncus murinus, respectively. Four Bartonella sequences were identified as B. tribocorum, B. queenslandensis, and B. phoceensis. The species of six sequences could not be determined. The strength of correlation ( r) between small mammal species and Bartonella species was 0.765. All the captured small mammals were negative for Y. pestis, hantavirus, F. tularensis, and pathogenic Leptospira. Conclusion The density of small mammals at Zhongshan port is relatively high. The small mammals in all the port areas have ectoparasite infestation. The small mammals in two port areas are positive for Bartonella, with high infection rates. Sanitation management and small mammal-borne disease control should be strengthened.

Objective To determine the current and future suitable areas of Elizabethkingia anophelis, and to provide a reference for preventing its outbreak and spread in China. Methods With 21 pieces of information on the geographical distribution of E. anophelis and data on 56 climatic factors, a MaxEnt model was used to estimate the suitable areas of E. anophelis in the world and China. R 4.2.2 software was used to adjust model parameters, and construct the receiver operating characteristic curve. The area under the curve was calculated to evaluate the accuracy of the model. The results were visualized using ArcGIS 10.5 software. Results Annual precipitation (bio12, 27.0%) and the minimum temperature in January (tmin01, 22.2%) contributed most to the distribution of E. anophelis. Under current climatic conditions, the highly suitable areas for E. anophelis were mainly distributed in the southeastern United States, northern South America, western Europe, central Africa, and parts of southeastern Asia; in China, they were mainly distributed in the wet regions south of the Qinling-Huaihe Line. Under future climatic conditions, climate changes of varying intensities generally promoted the suitable areas of E. anophelis in the world and China, especially under high radiative forcing. Conclusions There are large suitable areas for E. anophelis in the world and China under both current and future climate conditions, which are expected to be promoted with the change of climate in the future. Authorities should take measures to control greenhouse gas emissions to limit the increase of E. anophelis’ suitable areas. Provinces with its highly suitable areas should strengthen surveillance, risk assessment and response.

Objective To analyze the species composition and interannual and seasonal fluctuations of main host animals and flea vectors at historical and new plague foci in Jianchuan county, Yunnan province, China, and to explore the relationship between the population characteristics of hosts and vectors and plague epidemics. Methods Plague surveillance data were collected from Shaxi town surveillance point (historical) and Jinhua town surveillance point (new) in Jianchuan county, Yunnan province from 2012 to 2021. Descriptive and correlation methods were used to analyze the population characteristics of major host animals and fleas. Results The host animals found at Shaxi town surveillance point involved 22 species, 19 genera, 7 families, and 6 orders (outdoors:20 species, 18 genera, 7 families, and 6 orders; indoors:5 species, 4 genera, 2 orders, and 2 families). The host animals found at Jinhua town surveillance point involved 21 species, 17 genera, 6 families, and 5 orders (outdoors:20 species, 17 genera, 6 families, and 5 orders; indoors:10 species, 8 genera, 5 families, and 3 orders). The dominant species were Eothenomys miletus and Apodemus chevrieri at both monitoring sites, accounting for 37.73% and 45.90% in Shaxi town and 35.86% and 51.43% in Jinhua town, respectively. The fleas collected at the two surveillance sites involved 8 species, 8 genera, and 3 families (rodent body fleas:8 species, 8 genera, and 3 families; nest fleas:4 species, 4 genera, and 2 families). In Shaxi town, the body flea infestation rate was 28.91% (3 693/12 772), and the total flea index was 0.79 (10 144/12 772). In Jinhua town, the body flea infestation rate was 29.39% (959/3 263), and the total flea index was 0.71 (2 321/3 263). Frontopsylla spadix and Neopsylla specialis were the dominant species at both monitoring sites, accounting for 33.20% and 16.30% in Shaxi town and 36.49% and 19.09% in Jinhua town, respectively. Conclusion By comparing the population characteristics of main host animals and flea vectors at historical and new plague foci in Jianchuan county, it is indicated that the population characteristics of A. chevrieri and ectoparasitic F. spadix and N. specialis are more closely related to plague epidemics.

Objective To investigate the species composition of rodents and ectoparasitic fleas on rodents as well as the spatiotemporal distribution and changes of the flea index of dominant rodents in Xilin Gol League,Inner Mongolia Autonomous Region,China,and to provide a basis for plague risk assessment and its prevention and control decisions-making. Methods With the monitoring data of 12 plague surveillance points in Xilin Gol League from 2012 to 2021,we used descriptive epidemiological methods to analyze the temporal and spatial distribution characteristics of main rodents and their flea indexes. Results From 2012 to 2021,a total of 50 551 rodents were captured in Xilin Gol League,involving 18 species,13 genera,and 4 families. Among them,19 958 rodents carried fleas,with an average flea infestation rate of 39.48%. A total of 83 147 fleas were collected,belonging to 35 species/subspecies,14 genera,and 5 families,with an overall flea index of 1.64. Meriones unguiculatus, Spermophilus dauricus,and Lasiopodomys brandtii were the dominant rodent species. Citellophilus tesquorum mongolicus, Xenopsylla conformis conformis, Frontopsylla luculenta,and Nosopsyllus laeviceps kuzenkovi were the main parasitic fleas. M. unguiculatus carried more diverse flea species on the body surface than L. brandtii and S. dauricus. The mixed flea index ( S=-25.000, P=0.032) and S. dauricus flea index ( S=-23.000, P=0.049) showed a downward trend in Xilin Gol League during the ten years. The M. unguiculatus flea index and L. brandtii flea index had no significant changes. The S. dauricus flea index was significantly higher than the L. brandtii flea index ( H=15.000, P<0.001) and the M. unguiculatus flea index ( H=-15.000, P<0.001). There was no significant difference between the L. brandtii and M. unguiculatus flea indexes ( H<0.001, P=1.000). The mixed flea index peaked in July at 4.47. The M. unguiculatus flea index was significantly different between banners/counties of Xilin Gol League ( H=52.579, P<0.001), which was highest in Sonid Left and Xianghuang banners. The S. dauricus flea index was significantly different between banners/counties of Xilin Gol League ( H=73.253, P<0.001),which was highest in West Ujimqin and Zhengxiangbai banners. The L. brandtii flea index showed no significant difference between banners/counties of Xilin Gol League ( H=5.864, P=0.118). Conclusion The three types of plague foci in Xilin Gol League overlap. Meriones unguiculatus carries a diversity of fleas,with a high risk of transmitting plague bacteria. Surveillance points should comprehensively monitor plague epizootics to prevent plague from resurging among animals and expanding to human beings.

Objective: To analyze the species, composition, density, distribution, and seasonal fluctuation of flies in Fengxian District, Shanghai, China, so as to provide a basis for the prevention and control of flies in Fengxian District. Methods: The fly surveillance data in Fengxian District, Shanghai from 2011 to 2021 were collected, and Excel 2013 was used to summarize and analyze of the data. The Kolmogorov-Smirnov test was used to compare the density of flies in different habitats. Results: From 2011 to 2016, there was no significant change in the population density of flies in Fengxian District, ranging from 0.50 to 1.02 flies per cage of average annual density. In 2017 and 2018, the density of flies (1.76 and 5.25 flies per cage, respectively) increased significantly, by 70.87% and 409.71%, respectively, compared with 1.03 flies per cage in 2015. The fly density decreased year by year in 2019 and 2020, and increased in 2021, second only to the peak density in 2018. A total of 2 996 adult flies were captured, with an average density of 2.02 flies per cage. Muscina stabulans was the main species (accounting for 31.38%), followed by Boettcherisca peregrina (accounting for 28.64%). The flies density in large-scale green belts was highest with 2.32 flies per cage. The density of flies reached its peak in June, dropped sharply from July to August, and steadily decreased from September to November. Conclusions: There are more flies in large-scale green belts of Fengxian District, and the fly density peaks in June. The critical period to prevent fly-borne diseases is before June. Relevant departments in Fengxian District should raise and strengthen awareness of fly control. The environment management of large-scale green belt should be strengthened to reduce the breeding environment of flies.

Objective: To investigate the density distribution of Aedes mosquitoes in different habitats and seasonal fluctuation in Hangzhou, Zhejiang Province, China from 2017 to 2021, so as to provide a scientific basis for effective prevention and control, risk assessment, and early warning of dengue fever. Methods: According to the National Vector Surveillance Implementation Plan and the Zhejiang Provincial Vector Surveillance Plan, Aedes mosquitoes were monitored in 15 districts (counties and cities) in Hangzhou. Adult mosquitoes were monitored using the double-layered mosquito net method, and larvae were monitored using the Breteau index (BI) method. The surveillance time was set during April to November. The mosquito surveillance data of the 15 districts (counties and cities) were collected. Excel 2019 software was used for data analysis. The net trap index, BI, and container index (CI) were calculated. Categorical data were compared using the Chi-squared test. One-way analysis of variance was used for quantitative data. Results: From 2017 to 2021, the density of Ae. albopictus in Hangzhou by the double-layered mosquito net method was 2.54 mosquitoes/net·h, and no Ae. aegypti mosquitoes were captured. The density of adult mosquitoes was lowest in 2017 and highest in 2020. There was a statistical difference in the net trap index between different years (F=5.117, P=0.017). The seasonal distribution generally presented a bimodal pattern, with the peaks of mosquito densities mainly in July and October. The average BI from 2017 to 2021 was 9.18, and the peak period of the BI was during May to October. The CI showed that Ae. albopictus larvae were distributed in all kinds of water bodies. The CI differed statistically between different water bodies in the same year (all P < 0.001) and between different years in the same water body (all P < 0.001). Conclusions: Ae. albopictus density was high in Hangzhou, indicating a risk of dengue fever outbreaks and regional epidemics. It is recommended that the counties (cities, districts) take timely mosquito control measures according to the density, distribution, and seasonal fluctuation of mosquitoes.

Objective To establish a duplex droplet digital polymerase chain reaction (ddPCR) detection method for Japanese encephalitis virus (JEV) and West Nile virus (WNV). Methods Based on the designed primers and probes of JEV and WNV, a duplex ddPCR detection system for JEV and WNV was established. Its sensitivity, specificity, and repeatability were explored. The sensitivity was compared with the number of cycles required for the fluorescent signal to cross the threshold in each reaction tube of dual quantitative PCR. Results The detection sensitivity of the duplex ddPCR detection system could reach 10 ² copies/μl for both JEV and WNV, with good specificity and repeatability. No cross-reactivity was observed with the Dengue virus, Chikungunya virus, Zika virus, Tick-borne encephalitis virus, and human genome. Conclusion The established duplex ddPCR method shows high sensitivity and specificity for JEV and WNV detection, which provides a solution for detection for the two viruses in different scenarios.

Objective To assess the risk of Anopheles barbirostris invading China under future climate change scenarios, and to provide a basis for monitoring and early warning. Methods The maximum entropy model was used to predict the recent global potential distribution and project the future potential distribution of An. barbirostris in China. The main environmental factors affecting the distribution of An. barbirostris were analyzed based on the contribution rate of environmental factors. The vector risk assessment index system was established to calculate the comprehensive risk value of invasive species. Results A total of 99 effective distribution points of An. barbirostris were identified. The rainfall in September played a leading role in affecting the distribution of potential suitable areas of An. barbirostris. The omission rate of model training was roughly the same as the theoretical omission rate, and the area under the receiver operating characteristic curve was 0.988. Under the current climate scenario, the potential suitable areas of An. barbirostris in China were mainly in Guangdong province, Guangxi Zhuang Autonomous Region, and Hainan province as well as the eastern Sichuan Basin. In 2081-2100, China has the largest potential suitable area (207.51×10 ⁴ km ²) under the shared socioeconomic pathway 585 climate scenario, and the area of suitable area will show an increasing trend under various climate scenarios. Through the risk assessment index system, it was calculated that the comprehensive risk value of An. barbirostris was 0.57, so An. barbirostris belonged to the medium-risk invasive species. Conclusions An. barbirostris is a species with a medium invasion risk. In the future, the mosquito vector surveillance system should be improved according to the distribution of its suitable areas, and scientific prevention and control strategies should be formulated.

Objective To investigate the prevalence of 4 rodent-borne pathogens in small mammals in some areas of Shandong province, China, and to provide a scientific basis for the prevention and control of rodent-borne diseases. Methods From 2020 to 2021, small mammals’ liver, kidney, spleen, and lung samples were collected in Dongying, Weifang, Weihai, Linyi, Binzhou, and Heze of Shandong province. TaqMan fluorescent probe-based real-time polymerase chain reaction (PCR) was used to detect Leptospira and Bartonella. TaqMan fluorescent probe-based real-time reverse transcription PCR (RT-qPCR) was used to detect hantavirus and severe fever with thrombocytopenia syndrome virus (SFTSV). Excel 2016 and SPSS 20.0 softwares were used for statistical analysis. Results A total of 973 small mammals were collected, including 454 Rattus norvegicus, 441 Mus musculus, 21 R. tanezumi, 52 Apodemus agrarius, 4 Sorex spp., and 1 species of Cricetulus. The assay of lung tissues showed that 26 (2.67%) were positive for hantavirus. The assay of liver, spleen, and kidney tissues showed that 13 (1.34%) were positive for Leptospira and 36 (3.70%) were positive for Bartonella. No SFTSV was detected. The co-infection rate with hantavirus and Bartonella was 0.62% in R. norvegicus. Conclusion Small mammals in Shandong province carry a variety of pathogens including hantavirus, Leptospira, and Bartonella. It is necessary to strengthen the rodent-borne pathogen surveillance in small mammals and optimize the prevention and control of rodent-borne diseases to reduce the risk of human infection.

Objective To understand the distribution, density, and seasonal fluctuation of Aedes albopictus and the resistance of larvae and adults to different insecticides in Zibo city, China, in order to provide a scientific basis for risk assessment, prediction, early warning, and effective prevention and control of dengue fever, and to provide a theoretical basis for scientific and rational use of insecticides. Methods The density of mosquito larvae was monitored by Breteau index (BI) and mosq-ovitrap (MOT) methods. The density of adult mosquitoes was monitored by double-layer net method. Insecticide resistance was detected by bioassays recommended by WHO, including dipping method for larvae and contact tube method for adults. Results Among mosquito larval breeding containers, bonsai and aquatic plants showed the highest container index (CI) of 36.46%. The larvae were detected by BI and MOT in late-April and mid-May, respectively, with the peaks in mid-August and late-July, and almost disappeared in late-October. The average BI of larvae was 19.98, and the highest BI was 75.00 in August. Adult mosquitoes were detected in late-June, peaked in mid-August, and disappeared in mid-October, with obvious seasonal fluctuation. The median lethal concentration (LC ₅₀) of Ae. albopictus larvae to propoxur and temephos were 3.600 0 mg/L and 0.006 0 mg/L, respectively, which were 9.89 and 3.75 times of the sensitive strain. Adult mosquitoes showed resistance to permethrin (0.4%), deltamethrin (0.03%), beta-cypermethrin (0.08%), and beta-cypermethrin (0.07%). They were suspected to be resistant to propoxur (0.05%), bendiocarb (0.2%), and fenitrothion (0.2%). They were sensitive to malathion (0.5%) and chlorpyrifos (2%). Conclusion Ae. albopictus is widely distributed and has a high density in Zibo city, which may lead to local epidemics due to imported dengue cases. In Zibo city, Ae. albopictus larvae had developed resistance to propoxur and disulphos, while adult mosquitoes showed resistance to pyrethroid insecticides. Surveillance on the density and drug resistance of Ae. albopictus should be strengthened, and insecticides should be used scientifically and reasonably to effectively prevent the spread of dengue fever.

Objective To investigate the species composition, population density, and seasonal fluctuation of mosquitoes in human settlements and surrounding environments in Guizhou province, China, and to provide a basis for risk assessment of mosquito-borne diseases and scientific and effective vector control. Methods Mosquito surveillance data from 78 provincial vector surveillance sites in Guizhou province from 2017 to 2021 were collected to analyze mosquito species composition and compare mosquito population density and seasonal fluctuations in different years, regions, and habitats. SPSS 24.0 software was used to perform analysis of variance on the Breteau index (BI) and density of mosquitoes in different habitats for risk assessment. Results A total of 131 476 female mosquitoes were captured from 2017 to 2021, with a density of 5.82 mosquitoes/light·night. Culex pipiens quinquefasciatus accounted for the highest proportion with 43.34% of the total catches, followed by Anopheles sinensis with 20.68%. Cx. pipiens quinquefasciatus was the dominant mosquito species in most cities/prefectures. Zunyi had the highest composition ratio of Cx. pipiens quinquefasciatus with a total of 17 409 catches (61.32%). There was a statistical difference in mosquito density in different areas ( F=5.276, P<0.001). From 2017 to 2021, the highest densities of mosquitoes were all in livestock sheds, and Cx. pipiens quinquefasciatus was the dominant mosquito species in all habitats. The density of mosquitoes was statistically different in different habitats ( F=114.368, P<0.001). Adult mosquito density by light trapping increased gradually from May, peaked during June to August, and decreased rapidly from September. BI showed two obvious peaks in June and August, respectively. The BI began to rise rapidly in May, and gradually declined in September and October. The BI was greater than 5 for each year. The areas of level-1 risk included Anshun, Guiyang, and Qiandongnan Miao and Dong Autonomous Prefecture. The BI values in Anshun in 2019 and Guiyang in 2021 were both greater than 10, indicating a level-2 risk. Conclusions Cx. pipiens quinquefasciatus and An. sinensis are the dominant mosquito species in human settlements and surrounding environments in Guizhou province. The mosquito density is high in rural habitats, especially in livestock sheds, which are major mosquito breeding sites, and mosquito control should be strengthened in such environments. The peaks of mosquito activity in Guizhou province are in June and August, which may by closely related to the unique climate and rainfall conditions of Guizhou province. Mosquito control should be done before the peak breeding season of mosquitoes to reduce the density of mosquitoes and the risk of mosquito-borne virus transmission.