Objective To investigate the mosquito population, density and distribution in different habitats at Yunfu port in Guangdong province, and to provide the scientific evidence for controlling mosquito and vector - born infectious diseases. Methods Labour hour method, CDC light traps and mosquito magnet were taken for the survey of adult mosquitoes, scoop dipping method for the survey of larvaes and pupaes which would be identified after captured at the mosquito breeding site. The density of adult mosquitoes was obtained by monitoring mosquitoes with labour hour method in typical habitat. Results A total of 42 367 adult mosquitoes and 3680 larvaes were collected from May to November in 2011, which belong to 3 subfamily, 8 genera and 12 species. The dominant species are Culex tritaeniorhynchus, Cx. pipiens quinquefasciatus and Aedes albopictus successively. There were two peaks of adult mosquitoes density from May to November. The first is May and June, and the second is August. The biting activity of Ae. albopictus arised almost in one day, but the biting rate in the daytime was obviously higher than that at night. There were three biting peaks at one cycle. Conclusion It is the first time to obtain the original information of mosquito population at Yunfu port, which presented the mosquito population under natural conditions and would be useful to the ongoing survey and control of mosquitoes in the future.

In order to further get the mosquito fauna in Qinghai province, China, a survey of mosquito larvae breeding sites was conducted in Ledu county, Qinghai province from August to September 2018. Specimens of mosquito larvae were collected, and were made into pinned specimens for morphological taxonomic identification after they were reared to adults. In this investigation, Culex ( Culex) vagans Wiedemann, 1828 was found among the mosquito specimens collected from the rural household water storage tanks and the river ditches in Ledu county. Culex vagans was firstly recorded in Qinghai province, China.

Objective To understand the composition of main vector species in Zibo City in 2022, master its density and seasonal fluctuation, so as to provide scientific basis for vector biological control in Zibo City. Methods Four vectors of mosquitoes, flies, mice and cockroaches were monitored in Zibo City.Mosquito surveillance was carried out by the mosquito lamp trapping method and the Breteau index (BI) method. Cage trapping method was used to monitor flies. The night snap trapping method was used outdoors for rodent surveillance.The method of sticky trapping was used for cockroach surveillance. The difference of species composition in different habitats was determined by Chi-square test or Fisher’s exact probability method. Results In 2022, the average density of adult mosquitoes was 11.81 mosquitoes/light·night, and the highest density was 32.51 mosquitoes/light·night in August; the dominant species was Culex pipiens pallens; As for the larvae, BI were all>10.00 in July and August, and >20.00 in September. The average density of flies was 12.51 flies/cage, and the density reached the peak of 66.98 flies/cage in July; Musca sorbens was the dominant species. In 2022, the average density of rodents was 1.15%, with the peak of rodent activity in September, and the dominant rodent species was Rattus norvegicus. In 2022, the average density index of cockroaches in the city was 3.15 cockroaches/sheet, with the peak occurring in September, and Blattella germanica was the dominant species. The composition ratio of mosquitoes, flies and mice in different habitats was different, and the difference was statistically significant ( χ ²=3 160.149, 1 029.005, 33.394, all P<0.001). Conclusion The main disease vectors in Zibo city were Cx. pipiens pallens, M. sorbens, R. norvegicus and B. germanica. with high densities during July to September in summer. Appropriate measures should be taken to control the density of the vectors to prevent the spread of vector-borne diseases.

Objective To investigate mutations in the voltage-gated sodium channel gene ( VGSC) responsible for knockdown resistance (kdr) in Aedes aegypti and analyze the prevalence characteristics of the VGSC gene in the key areas of Ae. aegypti distribution in Yunnan Province, China. Methods Wild adult or larval Ae. aegypti samples were collected from 7 counties/cities (Yingjiang County, Ruili City, Zhenkang County, Gengma Dai and Va Autonomous County, Menghai County, Jinghong Municipality, and Mengla County) in Yunnan Province. The gene VGSC was amplified by direct sequencing to analyze the point mutation rate and the composition of combined mutations. The Chi-square test was used to compare the differences in the kdr mutation rate of VGSC gene between different loci and between different sexes of Aedes albopictus. Results The DNA was successfully extracted and VGSC gene were sequenced for a total of 561 Ae. aegypti mosquitoes (276 females, 242 males, and 43 larvae) in 7 counties/cities. Four point mutations were found in the VGSC gene. S989P, V1016G, and F1534C mutations were present in every county/city. The S989P mutation rate ranged from 71.43% to 100%, with a mean of 92.51% (95% confidence interval [ CI]: 90.33%- 94.70%). The V1016G mutation rate was 100%. The F1534C mutation rate was 55.81%-100%, with a mean of 85.38% (95% CI: 82.45%-88.32%). The Y1527F mutation was first detected in Ruili Municipality, Gengma and Zhenkang County, and the mutation rate ranged from 0 to 35.45%, with a mean of 8.73% (95% CI: 6.39%-11.08%). There were 4 types of co-occurring mutations: S989P+V1016G, V1016G+F1534C, S989P+V1016G+F1534C, and S989P+V1016G+Y1527F+F1534C. Single point mutations were not found. There were no significant differences in the mutation rates of 989, 1016, 1527, and 1534 loci and the composition ratios of combined mutations in female and male mosquitoes in six counties/cities except Yingjiang County. Conclusions The kdr mutation in the VGSC gene of Ae. aegypti in Yunnan Province is mainly characterized by multiple-point joint mutations, and a new Y1527F mutation appears. Kdr mutations surveillance in Ae. aegypti should be carried out regularly to grasp the changes in its resistance to insecticide targets in time.

Objective To investigate the species composition, population density distribution, and seasonal fluctuation of flies in Qingdao, China, and to provide a scientific basis for fly control. Methods Flies were monitored using the cage trap method. Fly species composition was analyzed using the chi-square test, and fly population density was analyzed using the Kruskal-Wallis H test. Results From 2017 to 2022, a total of 10 490 flies were caught, with a mean annual density of 12.14 flies/cage. The dominant fly populations were Sarcophagidae, Musca domestica, and Lucilia sericata, accounting for 22.73%, 17.58%, and 17.45%, respectively. The species composition of fly differed significantly in different years ( χ ²=4 863.573, P<0.001). The activity of flies spanned a long period from March to November. The seasonal peak of fly population density in different years all occurred in July, at 47.63, 32.13, 33.63, 23.00, 26.75, and 28.50 flies/cage, respectively, and there was a significant difference in the seasonal fluctuations of fly density between different years ( H=36.442, P<0.001). For different habitats, fly density was highest in farmers’ markets (15.27 flies/cage) and lowest in restaurant surroundings (7.26 flies/cage), with a significant difference in the density of each fly species between different habitats ( H=2.386, P=0.035). Among the dominant species, M. domestica had the highest density in residential areas (3.18 flies/cage), Sarcophagidae had higher densities in farmers’ markets (2.68 flies/cage), green belts (2.73 flies/cage), and residential areas (3.75 flies/cage), and L. sericata had the highest density in farmers’ markets (3.34 flies/cage). Conclusions Flies in Qingdao are mainly infested farmers’ markets and residential areas, peaking in July, and different fly species prefer different habitats. Fly seasonality, dominant species, and breeding characteristics should be considered in formulating targeted control measures to effectively reduce fly population density.

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

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

Both dengue fever (DF) and chikungunya fever (CHIKF) are important mosquito-borne viral diseases with global distribution, and these two diseases have relatively similar epidemiological and clinical features, with the main vectors of Aedes aegypti and Ae. albopictus. The local epidemic of DF occurred in China-Myanmar and China-Laos border areas of Yunnan province, China every year in 2013-2019, and it also occurred in China-Vietnam border area in 2019, while the local epidemic of CHIKF occurred in China-Myanmar border area for the first time in 2019. The imported cases of DF and CHIKF from Myanmar, Laos, Thailand, and/or Vietnam were the main cause of the local epidemic of these two diseases in Yunnan province. The special geographical location and ecological environment of Yunnan province are suitable for the breeding of the vector Aedes mosquitoes and the transmission of DF and CHIKF viruses. There are still high risks of re-epidemic or pandemic of DF and CHIKF in this region, with the possibility of endemic an severe cases of DF. At present, there is an urgent need to carry out in-depth research on the source of pathogens, the investigation of epidemic foci, clinical science, antibody level in population, and sustainable control of Aedes vectors, and meanwhile, control of cross-border spread, mosquito control, and joint prevention and control in China-Myanmar, China-Laos, and China-Vietnam border areas are the key prevention and control measures that need to be strengthened at present.

Objective To establish a multiplex real-time fluorescent quantitative reverse transcription polymerase chain reaction (multiplex real-time qRT-PCR) method for rapid detection of nucleic acids of Alongshan virus (ALSV) and Songling virus (SGLV). Methods Specific primers and TaqMan probes were designed for the conserved regions of the NS 3 gene of ALSV and the S gene of SGLV. A multiplex real-time qRT-PCR method was established for the two viruses, and the specificity, sensitivity, and repeatability of the method were evaluated. Tick specimens were used to verify the method. Results The detection method had no cross-reactivity with six other arboviruses, such as tick-borne encephalitis virus, with a sensitivity up to 1×10 ¹ copies/μl, and the coefficient of variation of cycle threshold for repeatability testing was less than 2.00%. Through this method, two groups of ALSV-positive specimens and one group of SGLV-positive specimens were detected from 30 groups of tick specimens collected from Heilongjiang, China in 2019. This method was verified to be 100% consistent with the general PCR method in terms of test results. Conclusion In this study, a highly sensitive and highly specific multiplex real-time qRT-PCR method for rapid detection of ALSV and SGLV has been successfully established.

Objective To investigate the current situation of vector control capacities of municipal and county-level centers for disease control and prevention (CDCs) in Shandong Province, China, so as to provide a basis for actively responding to the new situation of the prevention and control of vector-borne infectious diseases and improving vector control capacities of Shandong Province. Methods Through on-site interviews and questionnaire surveys, the information was collected on the vector control professionals and laboratory equipment of CDCs at the municipal and county levels in Shandong Province. Data were analyzed using WPS 2010 and SPSS 19.0 softwares. The t test or Wilcoxon’s rank-sum test was used for comparison of continuous data between groups, and the χ ² test was used for comparison of count data between groups. Results In Shandong Province, the average numbers of full-time personnel engaging in vector surveillance and control at municipal and county-level CDCs were 4.10 and 1.94, respectively. Among the professionals, junior and intermediate titles were more common, accounting for 34.43% and 36.79%, respectively; 46.70%(99/212) majored in preventive medicine (public health); and the majority had 1-5 years of work experience, accounting for 58.49%. The work mainly focused on carrying out ecological surveillance of disease vectors, and the vast vector laboratories were only able to carry out classification and identification disease vectors; The county-level CDCs undertook 59.38% of the training, and the average annual number of academic papers and scientific research achievements was 5.2 and 0.8, respectively. Conclusions In order to cope with the new challenges facing vector biological control, it is necessary to increase financial investment, strengthen talent and technical reserves, and strengthen scientific research and training. Professional and technical personnel should be based on the existing surveillance projects to strengthen data analysis and utilization, take more action in publicizing the knowledge of vector biological control, and continuously improve the level of social services.

Objective To analyze epidemiological characteristics and outbreak of dengue fever in Yunnan Province, China, so as to provide a scientific basis for formulating effective prevention and control measures. Methods Relevant data on dengue fever cases and outbreaks reported in Yunnan Province during 2013-2022 were collected from the “Infectious Disease Surveillance System” and “Public Health Emergency Management Information System” of “China Disease Control and Prevention Information System”. The concentration method was used to analyze seasonal characteristics. Excel 2007 software was used to sort out the data. MapInfo 7.8 software was used to draw the map. SPSS 26.0 was used to analyze the correlation, and the Chi-square test was used to compare the rate or composition ratio. The descriptive epidemiological method was used to analyze the epidemiological characteristics and outbreak response to dengue fever. Results A total of 16 774 cases of dengue fever were reported in Yunnan Province from 2013 to 2022, including 11 944 local cases, 4 521 overseas imported cases, and 309 domestic imported cases, with an average annual reported incidence of 3.53/100 000. The disease showed a high incidence every other year. The concentration ( M) was 0.84, showing strong seasonality. Imported cases mainly occurred from June to October, and local cases mostly from August to November. The male-to-female ratio of imported cases was slightly higher than that of local cases ( χ ²=37.596, P<0.001). The majority of local cases were 30～<40 years old (20.14%), and the majority of imported cases were 20～<30 years old (27.58%). The local cases were found in 5 border prefectures (cities). The overseas imported cases were mainly from southeast Asian countries and African countries, and Myanmar, Cambodia, and Laos were the main source countries (96.81%). The domestic imported cases were mainly from Xishuangbanna Dai Autonomous Prefecture (85.76%). The majority of cases were farmers, commercial service personnel, cadres/retirees, housekeepers, job-waiting people, and students. Commercial service personnel accounted for the highest proportion in local cases (21.89%), while farmers accounted for the highest proportion in imported cases (39.90%). There was a significant difference in occupational distribution between imported cases and local cases ( χ ²=1 535.415, P<0.001). A total of 28 dengue fever outbreaks were reported from 2013 to 2022, including 1 major event and 27 general events. The number of reported cases accounted for 83.41% of the total number of cases, and each event involved an average of 499.71 cases. The median time from the onset of the first case to the verification of event occurrence was 7 (5, 9) days, and the median duration of the outbreak was 110 (27, 140) days. Twenty-five outbreaks occurred in villages/communities. Conclusions Dengue fever in Yunnan has obvious seasonal, aggregated, and regional distribution patterns. We need to further strengthen imported case management, disease vector surveillance and control, and the prevention and control of dengue fever in key areas.

Objective To investigate the rodent species composition, density, and seasonality in different habitats based on the rodent surveillance program in Nanchang, China, so as to provide a basis for scientifically formulating rodent control strategies in Nanchang. Methods Three types of surveillance habitats including urban residential area, rural natural village, and special industry were chosen from 2017 to 2022. Rodent density was investigated by the night snap-trapping method. Descriptive methods were used to perform a statistical analysis of rodent species composition and seasonal variation of rodent density in three different habitats in Nanchang. With SPSS 26.0 and Excel 2021 softwares, descriptive methods were used to perform a statistical analysis of surveillance data, and the Chi-square test was used for comparison of rodent density across different years and habitats. Results A total of 104 121 effective traps were placed in Nanchang from 2017 to 2022, and 548 rodents were captured, with an average rodent density of 0.53%. The overall rodent density in the six years was statistically significant ( χ ²=34.857, P<0.001). A bimodal distribution with seasonal variation was found in the overall rodent density, the annual density of three dominant rodent species ( Rattus norvegicus, Mus musculus, and R. tanezumi), and the rodent density in residential areas and special industry habitats, while the rodent density in rural natural village habitats showed a unimodal trend, with the peak in July. The rodent density in rural natural villages (1.56%) was significantly higher than that in special industries (0.45%) and than that in urban residential areas (0.30%) ( χ ²=304.340, P<0.001). The dominant rodent species in urban residential areas and rural natural village habitats were R. norvegicus and R. tanezumi, while M. musculus predominated in special industry habitats (47.47%). The composition ratio of R. norvegicus in special industry and rural natural village habitats was decreasing year by year; the composition ratio of R. tanezumi in urban residential areas showed a decrease after increasing, while it was generally increasing in special industry and rural natural village habitats; the composition ratio of M. musculus in three different habitats showed an overall increasing trend. Conclusions The rodent density varies greatly in Nanchang from 2017 to 2022. The rodent density showed a bimodal distribution with seasonal changes and was high in rural areas. Specific control measures should be taken according to the changes in rodent species in different habitats to reduce the rodent density and the risk of rodent-borne diseases.

Objective By analyzing the surveillance data of host animals of hemorrhagic fever with renal syndrome (HFRS) in Guyuan, Ningxia Hui Autonomous Region (Ningxia), China from 2015 to 2021, to investigate the distribution of host animals of HFRS in Guyuan and their infection with viruses, so as to provide a basis for prevention and control, early warning and prediction of human epidemic in this region. Methods Small mammal trapping in field and residential areas in spring and autumn was carried out annually in accordance with the National Hemorrhagic Fever with Renal Syndrome Monitoring Program in the Jingyuan, Pengyang, Xiji, and Longde Counties and Yuanzhou District of Guyuan from 2015 to 2021. The density, distribution, and species composition were monitored by the night trapping method and analyzed, and the lung and blood specimens of small mammals were collected for antigen and antibody detection. The SPSS 23.0 software was used for statistical analysis, counting data were expressed as rates, and were compared with the Chi-square test ( P<0.05 indicates a statistically significant difference). Results From 2015 to 2021, a total of 5 515 small mammals were captured in Guyuan, with a mean density of 2.00%. The density of small mammals in the field areas (2.18%) was statistically higher than that in the residential areas (1.71%)( χ ²=55.920, P<0.001). The density of small mammals was statistically different across years and between different counties (districts) in the field areas ( χ ²=991.300, 1 202.179, both P<0.001); the dominant rodent species in Jingyuan County, Yuanzhou District, and Longde County were Apodemus agrarius, the dominant rodent species changed from A. agrarius to Rattus norvegicus in Longde county, and the dominant rodent species in Xiji County and Pengyang County were Cricetulus longicaudatus and Mus musculus, respectively. The density of small mammals was statistically different across years and between different counties (districts) in the residential areas ( χ ²=326.600, 430.500, both P<0.001), and the density of small mammals was generally below 5%. The dominant rodent species in Jingyuan, Xiji, Longde, and Pengyang were all M. musculus, and the dominant rodent species in Yuanzhou was R. norvegicus, with the proportion increased year by year. From 2018 to 2020, the density of small mammals showed a downward trend in the field and residential areas of Jingyuan and Longde, the field areas of Yuanzhou and Xiji, and the residential areas of Pengyang. The density of small animals increased statistically from 2020 to 2021 in the field and residential areas of Yuanzhou and Longde and in the field areas of Pengyang (all P<0.05). The infection rate (antibody positivity rate) of small mammals was 5.48 times the virus-carrying rate (antigen positivity rate) in the 7-year period; the virus-carrying rate of small animals was highest in Jingyuan County (1.05%), and the infection rate of small mammals was highest in Longde County (10.61%). The infection rate of small mammals in residential areas was statistically higher than that in field areas ( χ ²=12.675, P=0.008), while Hantavirus carrying of small mammals was only detected in the field areas. The virus-carrying rate of A. agrarius (2.94%) was higher than its infection rate (1.96%), and the infection rate of R. norvegicus (3.20%) was higher than its virus-carrying rate (0). Conclusions In recent years, the density of small mammals in Guyuan of Ningxia was generally low, but showed a slight increasing trend in the past two years; the density in the field areas was higher than that in the residential areas. The dominant rodent species were mostly A. agrarius in the field areas and M. musculus in the residential areas. The virus-carrying rate and infection rate of rodents increased significantly in 2021, suggesting that although the density, distribution, and composition of host animals of HFRS in Guyuan of Ningxia have not changed significantly, we still need to be vigilant for outbreaks of human epidemics.

Objective To verify the field efficacy of 0.2% curcumol baits against farmland rodents and determine the optimal dose. Methods A field experiment with 0.2% curcumol baits at three doses 1 500, 3 000, and 4 500 g/hm ² was carried out in the plague foci of Lijiang, Yunnan Province, China. The changes in rodent density,uterine development status, pregnancy rate, and litter size were investigated at 30, 60, and 90 days after baiting. The bait efficacy and intake level were calculated with the use of Excel 2010 software. Results The control effects of curcumol baits at 1 500, 3 000, and 4 500 g/hm ² groups were 47.06%, 51.87%, and 57.65% at 30 days, respectively; 50.00%, 63.64%, and 60.00% at 60 days, respectively; and 54.55%, 62.81%, and 50.91% at 90 days, respectively. The number of subadults decreased substantially, and the pregnancy rate and average litter size of female adult rodents also decreased. The curcumol bait intake coefficient of rodents was 0.77. No dead rodents or non-target organisms were observed during 15 consecutive days of investigation since the first day after baiting. Conclusion 3 000 g/hm ² of 0.2% curcumol baits is recommended for controlling farmland rodents based on the control effects and the economic threshold.

Objective To investigate common pathogen infections in small mammals in Ningbo, Zhejiang Province, China, so as to provide a basis for the prevention and control of rodent-borne diseases. Methods From 2020 to 2022, small mammals were captured using the night cage-trapping method in Zhenhai District, Ninghai County, Cixi and Yuyao cities of Ningbo. The small mammals were identified by morphological method, and their livers, spleens, lungs, and kidneys samples were collected. Real-time fluorescent quantitative PCR (qPCR) or reverse transcription-qPCR (RT-qPCR) was used to detect four pathogens: Hantavirus, Dabie bandavirus (i.e., Severe fever with thrombocytopenia syndrome virus), Leptospira, and Orientia tsutsugamushi. The differences in pathogen positive rates in the small mammals between different species, sexes, habitats, districts (counties, cities), and years were compared using the χ ² test or Fisher’s exact test. Results A total of 668 small mammals were captured, of which Rattus norvegicus (24.70%) and Niviventer confucianus (23.65%) were dominant species. The overall positive rate of the four pathogens in the small mammals was 9.43%, of which Hantavirus (all Seoul virus) and Leptospira accounted for 2.84% and 6.89%, respectively. Coinfections with two viruses were found, with a coinfection rate of 0.30%. Neither Dabie bandavirus nor O. tsutsugamushi was detected. There were significant differences in the overall positive rate of pathogens in the small mammals between different species and between different habitats (all P<0.001), but not between different sexes, different years, and different districts (counties, cities) (all P>0.05). Among various small mammal species, the positive rate of Hantavirus was the highest in Mus musculus and in R. norvegicus (10.00% and 8.48%, respectively); the positive rate of Leptospira was the highest in R. losea (15.38%). In different habitats, the positive rate of Hantavirus in small mammals was the highest in key industries (10.84%); the positive rate of Leptospira was the highest in urban residential areas (11.76%). In different districts (counties, cities), the positive rate of Hantavirus in small mammals was the highest in Cixi (9.90%). The positive rates of Leptospira in small mammals in Yuyao and Ninghai were higher, at 10.00% and 9.12%, respectively. Conclusions Infections with pathogens such as Hantavirus and Leptospira in small mammals are found in Ningbo, which pose a potential threat to the health of the local population. Targeted prevention and control measures should be taken to reduce the risk of human infections.

Marmota himalayana is an endemic species of the Qinghai-Tibet Plateau and an important part of its ecosystem, which plays a significant role in maintaining the ecological balance of the natural foci of plague. The distribution of marmots is influenced by environmental factors such as climate, soil, and vegetation, thereby determining the distribution and changes of natural plague foci and the risk of associated plague epizootics. In other words, the distribution of geographical landscape elements and the main host animals of plague play a decisive role in the distribution area of natural plague foci. Ecological research on M. himalayana has been widely reported. This paper reviews the research status in China and globally from the aspects of ecological, burrow, and habitat characteristics of M. himalayana, with the aim to improve the understanding of M. himalayana ecology and promote the application of ecology in plague prevention and control.

Objective From May 2017 to November 2021, there was an increased number of cases of fever with rashes admitted to Huoshan County Hospital in Lu’an City, Anhui Province, China. The aim of the study is to find out the etiology of the patients through epidemiological and clinical characteristic analysis, so as to provide a scientific basis for the prevention and control of the febrile illness with rashes. Methods An epidemiological investigation was carried out on the cases of fever with rashes through inquiring their medical histories and reviewing their medical records. The acute sera at admission and convalescent sera were collected from the patients to examine IgG antibody titers to Anaplasma, Borrelia burgdorferi, Orientia, Ehrlichia, Rickettsia rickettsii, and R. typhi using indirect immunofluorescence assay. An infection of a pathogen was determined by a 4-fold increase of the serum IgG antibody titer to the pathogen between the acute serum and the convalescent serum. The etiologic agent causing the outbreak was further identified by PCR amplification and DNA sequences of the rickettsial genes from acute serum. Results The IgG antibodies to Anaplasma, B. burgdorferi, and R. typhi were all negative in the acute sera of the patients. The positive rate of serum IgG antibodies to R. rickettsii was 51.52% (68/132) in the acute sera and 89.19% (33/37) in the convalescent sera. In the paired sera, the IgG titer had more than four time increase in the acute sera than in the convalescent sera. Phylogenetic analysis with the Rickettsia ompA sequence indicated that the etiologic agent formed a monoclade with newly identified Candidatus R. jingxinensis in Yunnan, China. Conclusion The febrile cases with rashes in Lu’an were serologically diagnosed as spotted fever rickettsial infection.