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 analyze the policies,strategies,techniques,actions,and achievements in the surveillance and control of vectors and vector-borne diseases in China since 2012. Methods Descriptive epidemiological methods were used to analyze and summarize the epidemiologic situation and challenges of vectors and vector-borne diseases,the surveillance of vectors,and the advances in the control of vectors and vector-borne diseases in China in the past ten years.The Mann-Kendall test was used to analyze the trend of the incidence rate of vector-borne diseases in the past decade using R 4.0.4 software. Results A series of policies,strategies,measures,and techniques were formulated and released for sustainable vector management in China in the past decade.The vector surveillance program in China had been continuously upgraded and improved,and a national vector surveillance network integrating ecology,etiology,and insecticide resistance had been established and improved.The number of national vector surveillance sites (1 097) in 2021 was increased by 54 times,and the funds input in national vector surveillance was increased by 127 times.Direct network reporting was realized for surveillance data,and there was a significant increase in the timely utilization rate of surveillance data,which provided better support for risk assessment,prediction and early warning,decision making,and control effect evaluation.The total annual incidence rate of vector-borne diseases in China in 2021(3.060/100 000) was reduced by 8.66% compared with that in 2007-2011(3.350/100 000),and the total annual mortality rate of vector-borne diseases in 2021(0.016/100 000) was reduced by 33.33% compared with that in 2007-2011(0.024/100 000).China had achieved the goal of malaria elimination and mitigated the accelerating increases in the incidence rates of dengue fever,scrub typhus,and severe fever with thrombocytopenia syndrome. Conclusion In 2012-2021,leapfrog development has been achieved for the policies,strategies,techniques,and actions for the surveillance and control of vectors and vector-borne diseases in China,and there are significant reductions in the incidence and mortality rates of vector-borne diseases.In view of the natural and social driving factors at present,the prevention and control of vectors and vector-borne diseases still face severe challenges,and therefore,it is urgent to further promote the strategies and measures for sustainable vector management,implement Global Vector Control Response 2017-2030,build proactive defense based on"reverse microbial etiology",so as to prevent and control major vector-borne diseases.

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, 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 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 analyze the genetic diversity of nine batches of Lasiopodomys brandtii rodents from three sample plots (New Barag Right banner, East Ujimqin banner, and Xilinhot city) of the Inner Mongolia Autonomous Region (Inner Mongolia), China by using 16 pairs of microsatellite primers. Methods A total of 275 L. brandtii rodents were trapped using snaps or cages in May, July, and September of 2021. DNA was extracted from them with magnetic beads, followed by PCR amplification with 16 pairs of fluorescent-labeled microsatellite primers. The microsatellite data were obtained using GeneMarker. The genetic diversity and structure of L. brandtii populations were analyzed using GenAIEx 6.5, Arlequin (version 30), and structure 2.3.4. Results A total of 472 alleles were detected by using 16 pairs of microsatellite primers. The average polymorphic information content was 0.821 3. The average Shannon’s information index was 1.812. Observed heterozygosity ranged from 0.478 to 0.951. Expected heterozygosity ranged from 0.575 to 0.891. According to cluster analysis and principal component analysis, the nine L. brandtii populations could be divided into four groups by month. The genetic diversity index of the four groups was May > July > September. The analysis of molecular variance showed that the variation among individuals (88.51%) was much greater than that among the groups (5.04%) and that among the populations (6.45%). The mantel test showed no significant correlation between genetic distance and geographical distance of L. brandtii ( R ²=0.001 6). Conclusions The L. brandtii populations sampled in Inner Mongolia had high genetic diversity. The genetic variation of L. brandtii populations was mainly observed among individuals. Seasonal variation could be the main factor affecting the genetic structure of L. brandtii populations.

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 analyze the results of tick ecological surveillance in Zhejiang province, China, 2017-2020, to understand species composition, density and seasonal fluctuation of ticks in Zhejiang province, and to provide a basis for the development of control measures. Methods Twelve surveillance sites for ticks were set up in Zhejiang province. Parasitic ticks were monitored by tick inspection on the body surface of animal and the questing ticks were monitored using drag-flag method. Ticks collected from the same sampling sites or animals were numbered uniformly or placed in the same tube and brought back to the laboratory for classification, identification, and counting. The monitoring data were processed and analyzed using Excel 2010 software. Results The parasitic tick index was 2.25 and the questing tick density was 0.48 ticks/flag·100 m in Zhejiang province, 2017-2020. Haemaphysalis longicornis was the dominant parasitic and questing tick. Among host animals, sheep had the highest tick index (4.29), followed by cattle (1.33). The dominant tick species were H. longicornis on sheep, Rhipicephalus microplus on cattle, H. longicornis on rural dogs, and R. sanguineus on urban dogs. The questing tick density was 0.94 ticks/flag·100 m in rural environment and 0.04 ticks/flag·100 m in scenic area. The tick density in Zhejiang province showed no obvious seasonal fluctuation. Conclusion In 2017-2020, the dominant tick species in Zhejiang province was H. longicornis. The dominant parasitic tick species varied across host animals, and sheep had the highest tick infestation rate. The questing tick density in rural environment was significantly higher than that in scenic area. The results can provide a reference for the public health institutions of Zhejiang province to formulate targeted tick and tick control measures.

Repellents can repel blood-sucking insects and reduce bites by affecting their olfactory system,thus preventing the occurrence of insect-borne diseases. Repellents are widely used because of their safety at the recommended dose. However,with the long-term accumulation of observation data,the toxicity cases caused by repellents have attracted extensive attention,such as toxic encephalopathy in children induced by diethyltoluamide and asthma-like allergic reaction induced by permethrin. Therefore,summarizing the long-term toxicity of repellents and deeply exploring the intrinsic mechanism provide a theoretical basis for the development of safer repellents and have an important scientific and application value. This paper reviews the latest progress of studies on safety events and mechanisms of currently applied major repellents, and considers the development trend and research direction of repellents.

Objective To understand the epidemiological characteristics of severe fever with thrombocytopenia syndrome (SFTS) and tick vectors in Zhejiang province of China in 2021. Methods The data on SFTS cases in Zhejiang province in 2021 were obtained from China Information System for Disease Control and Prevention, and descriptive epidemiological methods were used to describe the temporal, population, and regional distributions of SFTS cases. Tick surveillance sites were set up in 8 counties (cities/districts) of Zhejiang province from March to October 2021, and the drag-flag method was used to collect free-living ticks and the body surface examination method for on-host ticks. Excel 2013 and SPSS17.0 softwares were used to perform a statistical analysis of the data on SFTS cases and vector surveillance data, and ArcGIS 10.0 software was used to draw the map of SFTS incidence rate in districts and counties. Results A total of 85 SFTS cases were reported in Zhejiang province in 2021, with a reported incidence rate of 0.15/100 000 and a fatality rate of 8.24% (7/85). The cases were distributed in 23 counties (cities/districts) in 8 prefectures, and the top 3 prefectures in terms of the number of cases were Jinhua (27 cases), Taizhou (27 cases), and Ningbo (11 cases) cities. The cases mainly occurred in April to October, with a peak in May to July. There was no significant difference in incidence rate between the male patients and the female patients ( χ ²=1.347, P=0.246); as for the age of onset of SFTS, most cases were middle-aged and elderly patients, with a median age of 67 years; most of the patients were farmers, accounting for 80.00% (68/85). The patients with a clear history of tick bites within 2 weeks before SFTS onset accounted for 17.65% (15/85). A total of 590 free-living ticks were collected in the unpopulated rural area, and the mean density of free-living ticks was 18.44 ticks/flag·h. A total of 688 animals were monitored and 2 406 on-host ticks were collected, with a mean density of 3.50 ticks per host. Conclusion Sporadic cases of SFTS are mainly observed in Zhejiang province, with obvious regional and seasonal characteristics. The middle-aged and elderly people and farmers were the main affected populations. Free-living ticks and on-host ticks show a relatively high density as the vector for SFTS.

Objective To predict the potential distribution of Euglandina rosea in China under current and future climatic conditions via an optimized maximum entropy (MaxEnt) model, and to provide a theoretical basis for the prevention and control of invasion of E. rosea in China. Methods The global occurrence records of E. rosea were collected and screened using ENMtool. Maxent 3.4.1 and GraphPad Prism 8 were used to screen environmental variables according to the contribution rate of environmental variables, the jackknife method, and the correlation analysis of variables. The "kuenm" package was run in R 4.0.4 software to calculate and adjust the model parameters by means of regularization multipliers and feature combinations. The optimized MaxEnt model was used to predict the potential distribution of E. rosea in China under current and future climate scenarios. ArcGIS 10.7 was used to process the results and map the images. Results A total of 780 E. rosea occurrence records were identified, and four environmental variables were used to construct the MaxEnt model. The area under the curve (AUC) of the model was 0.963. The most influential environmental factors on the distribution of E. rosea were precipitation of the driest quarter and the highest temperature in February. The MaxEnt model predicted that the current potential areas of E. rosea were distributed in the southeast of China, concentrated in Fujian province, Guangdong province, and central Guangxi Zhuang Autonomous Region. It would gradually expand northward to Hunan province, Jiangxi province, central Anhui province, eastern Hubei province, and some areas of Zhejiang province in the future. Conclusions E. rosea has potential distribution in China. With global warming, its potential habitat areas will gradually expand, while at lower latitudes in the southeast they will slightly shrink. As a result, the overall center of potential areas shifts northward.

Objective To investigate the density and seasonal fluctuations of vector mosquitoes in Hangzhou, Zhejiang province, China from 2017 to 2021, and to provide a scientific basis for vector control and mosquito-borne disease prevention. Methods The light trap method was used to investigate 15 districts/counties/cities in Hangzhou from April to November, 2017-2021, in accordance with the "National Vector Surveillance Program" and "Zhejiang Province Vector Surveillance Program". Excel 2016 software was used to summarize the monitoring data, and SPSS 21.0 software was used for statistical analysis. The Chi-square test was used for the difference of mosquito composition ratio in different years, and one-way ANOVA was used for the difference of mosquito density in different habitats. Results From 2017 to 2021, the mosquito density in Hangzhou was 1.99 mosquitoes/light·night, and Culex pipiens pallens/quinquefasciatus (71.90%) was the dominant species. The seasonal fluctuation trend of mosquito density generally showed a bimodal curve, peaking in July and October. There were statistical differences in densities of Cx. pipiens pallens/quinquefasciatus, Cx. tritaeniorhynchus, Aedes albopictus, Anopheles sinensis, and Armigeres subalbatus between different years (all P<0.001). In terms of various habitats, livestock barns/farms had the highest mean mosquito density (4.92 mosquitoes/light·night), and hospitals had the lowest (1.35 mosquitoes/light·night). There were statistical differences in densities of An. sinensis and Ar. subalbatus between various habitats ( F=3.581, P=0.023; F=5.431, P=0.004). Cx. pipiens pallens/ quinquefasciatus was the dominant mosquito species in various habitats, followed by Cx. tritaeniorhynchus, Ar. subalbatus, Ae. albopictus, and An. sinensis. Livestock barns/farms had the highest mosquito densities in terms of any of the above five species. Conclusions The mosquito density in Hangzhou is generally at a low level. Cx. pipiens pallens/ quinquefasciatus is the dominant species. In future mosquito control, livestock barns/farms should be highlighted for special attention. Local districts/cities/counties should take targeted mosquito control measures based on their density changes, distribution, and seasonal fluctuations.

Objective To investigate the genetic diversity, genetic differentiation, and phylogenetic relationship of Culex pipiens pallens populations in Shangdong, China. Methods Cx. pipiens pallens populations were collected in Heze, Dezhou, Liaocheng, Qingdao, Yantai, and Rizhao, Shandong province from September 2020 to September 2022. Genomic DNA was extracted from a single female adult mosquito. The mitochondrial cytochrome c oxidase subunit Ⅰ (mtDNA-COⅠ) gene sequences were amplified by polymerase chain reaction and sequenced afterwards. The acquired sequences were compared with those in the Basic Local Alignment Search Tool on the GenBank. BioEdit 7.0 was used to compare and analyze the sequencing results. DnaSP v6 was used to analyze the genetic diversity of populations. Arlequin 3.5 was used to calculate the genetic differentiation coefficient and gene flow of populations. PopART 1.7 was used to construct the haplotype network (TCS network). Results A total of 423 sequences of 603 bp were obtained from 6 Cx. pipiens pallens populations in Shandong province. The average content of A+T bases was 69.2%, which was consistent with the AT bias of mitochondrial DNA. There were eight haplotypes in the haplotype analysis, of which haplotype H01 was the dominant haplotype. The results of mtDNA-COⅠ sequence analysis showed that the population had rich genetic diversity. The results of molecular variance analysis indicated that the genetic differentiation of Cx. pipiens pallens mainly came from within the population; there was some genetic differentiation among some populations. The results of neutrality test showed that the populations of Cx. pipiens pallens in Liaocheng and Heze experienced expansion recently. Conclusions The mtDNA-COⅠ gene can be used as a molecular marker to study the genetic diversity of Cx. pipiens pallens populations. The genetic development of Qingdao population is special compared with other geographical populations.

Objective To investigate the effect of Misgurnus anguillicaudatus endemic to China in controlling the larvae of Aedes albopictus, and to provide new ideas for biological control of mosquitos. Methods M. anguillicaudatus individuals were divided into two juvenile and adult groups. After weighing and fasting for 24 h, they were put into tanks with 100, 200, 400, and 1 000 larvae/basin. Gambusia affinis with the same weight was used as control group (multiple G. affinis fish with the same average weight as the two groups of M. anguillicaudatus were used). The numbers of larvae and pupa were counted at 1, 2, 4, 6, 8, and 24 h to compare the ability to devour the larvae of Ae. albopictus between M. anguillicaudatus at different growth stages and between M. anguillicaudatus and G. affinis. Results Each juvenile M. anguillicaudatus devoured 984 larvae per day on average, while each adult M. anguillicaudatus devoured 647 larvae per day on average. With the same density of Ae. albopictus larvae, juvenile M. anguillicaudatus devoured more larvae than G. affinis of the same weight ( F=58.051, P<0.001), whereas adult M. anguillicaudatus devoured fewer larvae than G. affinis of the same weight ( F=23.162, P<0.001). A 7-day experiment was conducted with juvenile M. anguillicaudatus for continuous devouring of larvae. The results showed stable daily devouring of larvae in the short and medium term. There were no significant differences in the number of mosquito larvae devoured per day ( χ ²=2.650, P=0.266), and the number was significantly higher than that of G. affinis of the same weight ( χ ²=16.758, P=0.001). Conclusion M. anguillicaudatus has good ability to devour Ae. albopictus larvae, and can be used as a new method to control mosquito larvae in small water bodies in residential areas.

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 investigate the level, trend, and epidemiological characteristics of scrub typhus in Changzhou, China, and to provide a basis for prevention and control of the disease. Methods The reported data of scrub typhus in Changzhou from January 1, 2012 to December 31, 2021 were collected from the China Information System for Disease Control and Prevention. We analyzed the incidence of the disease and described the regional, temporal, and population distribution characteristics of scrub typhus using descriptive epidemiology method. Results From 2012 to 2021, a total of 149 cases were reported in Changzhou, with a median annual reported incidence rate of 0.28/100 000, with the highest reported incidence rate of 0.74/100 000 in 2015 and the lowest rate of 0.04/100 000 in 2012. Cases were reported in all districts of Changzhou, with the top three being Wujin district (60, 40.27%), Xinbei district (34, 22.82%), and Liyang city (20, 13.42%). Most cases were reported between October and November in farmers, household workers, and unemployed persons, and in persons aged 45-69 years. Conclusions Scrub typhus surveillance should be strengthened, medical personnel should be trained to improve the diagnosis of scrub typhus, and health education for high-risk populations should be carried out, in order to prevent and control the occurrence and prevalence of scrub typhus.

Objective To investigate the resistance of Musca domestica populations to commonly used insecticides in different regions of Zhejiang province, China, in 2021, and to provide a scientific basis for rational insecticide use of fly control. Methods Different field populations of M. domestica were collected from 12 monitoring sites in Hangzhou, Ningbo, Wenzhou, Shaoxing, Huzhou, Jiaxing, Jinhua, Quzhou, Taizhou, Lishui, Zhoushan, and Yiwu, Zhejiang province from April to November 2021. The topical application method was used to determine the resistance of M. domestica to seven commonly used insecticides of pyrethroids, organophosphorus and carbamates. Results The resistance ratios of M. domestica populations to beta-cypermethrin, deltamethrin, permethrin, beta-cyfluthrin, dichlorvos, chlorpyrifos, and propoxur were 0.83-255.00, 4.44-158.78, 6.11-64.81, 1.76-53.57, 2.45-130.11, 3.37-10.39, and 2.52-1 149.63 in 11 prefecture-level cities and Yiwu, Zhejiang province. Conclusion Some field populations of M. domestica in different regions of Zhejiang province have developed varying degrees of resistance to many of the seven commonly used insecticides. In the future fly control, measures should be taken to standardize the use of chemical insecticides based on the results of resistance monitoring in order to effectively reduce the density of flies and delay the development of resistance.