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 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.

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 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.

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.

Objective To investigate the bionomic characteristics of mosquito populations in Sichuan province, China from 2017 to 2021, and to provide a scientific basis for mosquito control and risk assessment of mosquito-borne diseases. Methods Adult mosquito surveillance data in 21 cities/prefectures of Sichuan province from 2017 to 2021 software were collected. Mosquito surveillance was conducted continuously using the light trap method. Excel 2007 and SPSS 25.0 softwares were used for statistical analysis. Results From 2017 to 2021, the mean mosquito density was 1.60 mosquitoes/lamp·hour at 21 surveillance sites in Sichuan province. The mosquito density generally fluctuated at similar levels in the five years. The dominant mosquito species were Culex pipiens quinquefasciatus, Cx. tritaeniorhynchus, and Anopheles sinensis, accounting for 35.64%, 33.98%, and 10.78% of the total catches, respectively. Among all habitats, the overall mosquito density was highest in livestock sheds (4.51 mosquitoes/lamp·hour) and lowest in hospitals (0.39 mosquitoes/lamp·hour). The overall mosquito density in rural areas was statistically higher than that in urban areas ( Z=-6.523, P<0.001). The seasonal variation curve of mosquito density in Sichuan province showed a single peak, which occurred during June to July. Conclusion The mosquito densities were relatively low at surveillance sites in Sichuan province except for 2019. The dominant mosquito species were Cx. pipiens quinquefasciatus, Cx. tritaeniorhynchus, and An. sinensis. The rural areas had the highest mosquito density, which should be the key area for mosquito control. May to September was the peak period of dominant mosquito activities, and comprehensive mosquito control should be strengthened during this period.

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 analyze the epidemiological characteristics of hemorrhagic fever with renal syndrome (HFRS) in China from 2006 to 2021, to investigate the influence of non-pharmaceutical intervention against coronavirus disease 2019 (COVID-19) on HFRS prevalence, and to provide a scientific basis for the subsequent formulation of relevant policies. Methods Descriptive epidemiological methods were utilized to statistically analyze the epidemiological characteristics of HFRS in China from 2006 to 2021. The data of HFRS cases from 2006 to 2019 were used to establish an autoregressive integrated moving average (ARIMA) model to predict the number of HFRS cases in 2020-2021, and the predicted values were compared with the actual observed values. Results The number of HFRS cases in China was relatively stable in 2006-2021, and the number of deaths were significantly reduced. HFRS had obvious seasonality, with two peaks of incidence in a year, i.e., May-June and November. The number of cases in northeast China decreased, but the affected areas in the whole country expanded, and some areas were still at risk of outbreak. The number of male cases was significantly higher than that of female cases. The peak age group of onset was 35-49 years for males and 45-59 years for females, and there was a significant difference in the age composition between males and females ( χ ²=2 802.807, P<0.001). Farmers were the main affected population, accounting for more than half of the total cases. The seasonal ARIMA model was established by fitting the data of HFRS cases from 2006 to 2019 with R 4.0.4 software, which was (2,0,2)(1,1,0) ₁₂ and was well fitted. The actual observed value of HFRS cases in 2020-2021 was close to the predicted value, within its 95% confidence interval. Conclusion HFRS is an important public health problem in China and the overall trend of its prevalence is relatively stable. It is necessary to strengthen the surveillance and implement more accurate prevention and control measures. The measures for COVID-19 prevention and control in China have no significant impact on the prevalence of HFRS during 2020-2021.

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 species and prevalence of viruses carried by sandfly specimens in Wuxiang county, Shanxi province, China. Methods Sandfly specimens were collected in Wuxiang county, Shanxi province in June 2018, and virus isolation was conducted using two cell lines of golden hamster kidney cells (BHK-21 cells) and Aedes albopictus egg cells (C6/36 cells) preserved in the laboratory. The positive isolate was subjected to viral RNA extraction and cDNA library preparation, followed by viral gene amplification, nucleotide sequence determination, and phylogenetic analysis. Results The SXWX1816-2 strain caused cytopathic effects in mammalian cells (BHK-21 cells), but no cytopathic effect in insect cells (C6/36 cells). The results of nucleotide sequence determination and analysis of the virus genome showed that the lengths of nucleotide sequences in the coding region of M and S genes of the virus were 4 089 and 1 611 nt; the results of nucleotide and amino acid sequence homology and phylogenetic analysis of M and S genes of the virus showed that the SXWX1816-2 strain belonged to the Phlebovirus genus from the Phenuiviridae family, which shared the highest homology and closest phylogenetic relationship with Wuxiang virus (WUXV) previously isolated in China. Conclusions This study clarifies the taxonomic status of the virus (SXWX1816-2) isolated from natural sandflies in China. The results provide important basic data for the research on viruses carried by blood-sucking insects in China, especially the virus carried and transmitted by sandflies.

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 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, species composition, and seasonal fluctuation of rodents in Liaoning province, China from 2018 to 2020, and to provide a scientific basis for formulating rodent control strategies. Methods Surveillance points were set in residential regions and special industries for urban areas, and in natural villages for rural areas. Rodent density was monitored using the night trapping method. With SPSS 23.0 and Excel 2013 softwares, descriptive methods were used to analyze the species composition and seasonal variation of rodents in the urban and rural areas of Liaoning province. Results From 2018 to 2020, a total of 207 738 effective rodent traps were set in Liaoning province. A total of 2 237 rodents were captured, with an average rodent density of 1.08%. The rodent density in rural areas (1.53%) was statistically higher than that in urban areas (0.63%). The urban rodent density and overall rodent density in 2018 and 2019 showed a unimodal curve, all peaking in July. The rural rodent density and overall rodent density in 2020 showed a bimodal curve. Rattus norvegicus was the dominant rodent species in Liaoning province. Conclusion Rodent density showed a slight downward trend in Liaoning province from 2018 to 2020, with a unimodal pattern in 2018 and 2019 and a bimodal pattern in 2020. There was a relatively high rodent density in rural habitats, where rodent control should be strengthened. Based on the seasonal fluctuation of rodents, comprehensive rodent control measures should be taken before the peak period, to reduce the density of rodents and thereby prevent rodent-borne diseases.

Mosquito-borne viruses are transmitted mainly by mosquitoes during blood feeding. These viruses include more than 100 species and can cause many infectious diseases and seriously threaten human health. The accurate and rapid detection of mosquito-borne viruses in field is an important part of preventing and controlling mosquito-borne diseases. Field detection allows earlier disease prevention and control and helps control the outbreaks and epidemics of mosquito-borne diseases. However, current detection methods mainly target clinical samples and cannot be used for on-site detection of viruses in mosquito samples. This paper reviews the detection methods for mosquito-borne viruses, including the classical isolation and culture, antigen detection, and nucleic acid detection methods, as well as the new technologies developed rapidly in recent years, such as isothermal amplification and clustered regularly interspaced short palindromic repeats-associatied (CRISPR-Cas). The characteristics of these methods are analyzed, and the directions of developing technologies for monitoring mosquito-borne viruses in field are discussed.

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 investigate the technical capabilities of malaria control institutions in China, and to provide a reference for malaria control in the post-eradication era as well as foreign medical aid. Methods Two self-made questionnaires were used to investigate the technical capabilities (malaria control and mosquito vector surveillance) of provincial centers for disease control and prevention and institutes of parasitic diseases. The capacity for malaria diagnosis and treatment of medical institutions was analyzed based on the data on malaria cases from the China Information System for Disease Control and Prevention. The relevant official websites were browsed to collect the antimalarial products and enterprises with prequalification certificates from the World Health Organization (WHO) or registration approvals from the National Medical Products Administration. By reviewing the literature to tease out the technical progress in vaccines, drugs, and other fields of malaria. The data of foundations and other institutions were collected by means of expert consultation and interview. Results National vector surveillance sites were set in all 31 provinces, autonomous regions, or municipalities directly under the central government and Xinjiang Production and Construction Corps ("province" below), with 5.35 sites per province. There were 178 staff members, with 5.74 persons per province. Over 26 provinces had mosquito vector laboratories and mosquito breeding rooms, and carried out mosquito density surveillance, mosquito species and ecology research, and insecticide types and resistance research. Forty-seven persons from 30 provinces had WHO certificates of microscopy. Twenty-four malaria endemic provinces had 227 staff members for malaria prevention and control, with 9.45 persons per province. Among them, 63.88% were aged 30 to 49 years, 52.42% had a senior or vice-senior title, and 58.59% had ≥ 10 years of working in malaria. All the 24 provinces had malaria laboratories, and there were 145 malaria laboratories in total (6.04 laboratories per province), all with the abilities of plasmodium blood smear microscopy and nucleic acid detection. Sixteen provinces had approvals of foreign aid projects or provincial/ministerial/above level research projects, with 56 projects in total, covering Asia, Africa, and Oceania. WHO-prequalified enterprises included 26 manufacturers of active pharmaceutical ingredients, three manufacturers of long-lasting insecticidal nets, one medicine manufacturer, and one insecticide manufacturer. Forty-eight companies of antimalarial drugs had registration approvals from the National Medical Products Administration. At least 77.30% of medical institutions had certain capacities for the diagnosis and treatment of falciparum malaria. Artemisinin and its derivatives developed by the China Academy of Chinese Medical Sciences were the only WHO-recognized specific antimalarial drugs. Pfcp-2.9 antigen developed by universities was approved for clinical trials. Two vaccines were put into preclinical studies. At least 31 customs ports were capable to monitor Anopheles mosquitoes, and four customs ports had malaria rapid diagnostic test abilities accredited by the College of American Pathologists. The WHO, Global Fund, Bill & Melinda Gates Foundation, Health Poverty Action, Chinese Preventive Medicine Association, and China Chamber of Commerce for Import & Export of Medicines & Health Products played important roles in malaria elimination in China by providing funds, organizing technical training, participating in malaria elimination assessment, and helping enterprises apply for WHO prequalification. Conclusion China has established multiple work networks nationwide, built joint prevention and control mechanisms involving multiple departments, and accumulated technical talents with high professional levels in various technical fields, but still with shortcomings in some technical fields.

Objective To analyze the epidemic situation of hemorrhagic fever with renal syndrome (HFRS) and the populations distribution and Hantavirus infection status of the host animals in Zhejiang province, China in 2021, and to provide scientific evidence for establishing preventive measures. Methods Descriptive epidemiological methods were used to analyze HFRS case data and host surveillance data, which were online reported in the Communicable Disease Surveillance Information Reporting and Management System of Zhejiang province in 2021. The Chi-square test was used for rate comparison. Results A total of 180 HFRS cases were reported in Zhejiang province in 2021, with a mean annual incidence rate of 0.29/100 000. Most cases were observed in Taizhou, Ningbo, Shaoxing, and Quzhou. The cases distributed throughout the year, peaking during May to June in summer and December in winter at similar levels. The high-incidence group aged over 40 years old, accounting for 76.67% (138/180) of the total cases. The main occupation was farmers, accounting for 61.67%. A total of 11 921 effective traps were set in the five surveillance sites in Zhejiang province, capturing 660 small mammals, with an average capture rate of 5.54%. A total of 660 serum samples of small mammal were detected, among which 35 (5.30%) were antibody-positive. Hantavirus was positive in 15 of 660 (2.27%) small mammal lung samples. There were statistical differences in capture rate ( χ ²=16.161, P<0.05), the positive rate of HFRS antibody ( χ ²=14.957, P=0.005), and the virus infection rate of small mammals ( χ ²=8.413, P=0.048) among the five surveillance sites. Conclusions HFRS was sporadic at a low level and distributed in extensive areas in Zhejiang province in 2021. The surveillance sites had generally high small mammal densities and fluctuating virus infection rates in small mammals, requiring scientific rodent control-based comprehensive prevention and control measures.

Objective To investigate the epidemiological characteristics of person, time, and place of dengue fever and their domestic and abroad sources in Guangxi Zhuang Autonomous Region (Guangxi), China from 2016 to 2020, and to provide a scientific basis for the prevention and control of dengue fever in the future. Methods The data on dengue fever in Guangxi from 2016 to 2020 were collected from the notifiable disease reporting system. With Excel 2010 and SPSS 20.0, descriptive epidemiological methods were used to analyze the epidemiological characteristics of imported and local cases of dengue fever in Guangxi in the past five years, and to analyze the source of infection and the epidemic pattern of dengue fever in Guangxi. Results A total of 2 183 dengue cases were reported in Guangxi from 2016 to 2020, with an average incidence of 0.89/100 000. Dengue fever was sporadic during 2016 to 2018, and occurred in outbreaks in 2019 and 2020. The incidence of dengue fever peaked in 2019, accounting for 80.20% of the total reported cases. The male-to-female ratio of imported cases was statistically higher than that of local cases ( χ ²=5.262, P=0.022).The majority of local cases were between 30 and 39 years old (22.61%) and the majority of imported cases were between 30 and 39 years old (27.94%). The local and imported cases showed similar trends in epidemic seasons, mainly in summer and autumn. The imported cases were mainly from Guangdong province in China (74 cases, 88.10%) and from Cambodia (83 cases, 65.35%). In terms of occupational distribution, domestic and overseas imported cases were mainly household workers and unemployed workers, accounting for 20.78% and 20.47% respectively, while domestic imported cases were mainly farmers (43.03%). Conclusion Dengue fever in Guangxi has an increased trend from sporadic patterns to outbreaks. It is important to strengthen the education on dengue control for key populations during epidemic seasons, to enhance the sensitivity of quarantine at entry and exit ports and the level of diagnosis in medical institutions, and to promptly identify and report cases, which are important for reducing the occurrence and spread of dengue fever.

Objective To determine the resistance status of Aedes albopictus to commonly used insecticides in Wuhan, China, 2019-2021, and to provide a basis for formulating scientific and reasonable prevention and control measures. Methods Insecticide susceptibility tube test was used to examine the mortality of Ae. albopictus adults to six insecticides at the diagnostic dose, and larva dipping test was used to examine the toxicity of nine insecticides to Ae. albopictus larvae. SPSS 20.0 software was used for probability regression analysis to calculate the median lethal concentration or half maximal inhibitory concentration of the insecticide to Ae. albopictus larvae. Results Ae. albopictus adults developed varying degrees of resistance to deltamethrin, permethrin, beta-cypermethrin, and lambda-cyhalothrin, with mortality rates ranging from 5.88% to 68.75%, and showed sensitivity to propoxur and malathion, with mortality rates of 100% . Ae. albopictus larvae demonstrated different degrees of resistance to deltamethrin, beta-cypermethrin, propoxur, Bacillus thuringiensis, and pyriproxyfen, with resistance ratios ranging from 4.40 to 76.20, and showed sensitivity to malathion and temephos, with resistance ratios of 0.30 and 2.38, respectively. Conclusion Ae. albopictus in Wuhan develops varying levels of resistance to different types of insecticides, including pyrethroids, carbamates, biological insecticides, and insect growth regulators. Surveillance and management of resistance of Ae. albopictus should be strengthened to further improve to formulate scientific, reasonable, and comprehensive prevention and control measures.