Inland Cities Research Articles

Research on the Updating and Selection of Greening in Sponge Cities

With the frequent occurrence of urban waterlogging, the concept and construction of sponge city have been carried out in many inland cities. Urban greening is not only an integral and important part of sponge cities, but also has a considerable impact on climate and urban landscape. This paper analyzes the function and existing problems of sponge city greening. In the past planning, the selection of certain trees brought problems such as flying catkins and pollen to people’s lives. Not only are they an allergen for many residents, but they also pose a fire hazard. At the same time, the construction of some green facilities lacks rationality. They are not only difficult to play the role of interception, but also easy to water in the flower bed in rainy weather, resulting in root rot. In addition, this paper also discusses the improvement of tree species and greening facilities. For some problem trees which are planted in a large area and difficult to renew in a short time, some mitigation measures are put forward. Finally, the vertical greening and rainwater gardens which have great potential in the green selection of sponge city are introduced. This paper is devoted to exploring more scientific and reasonable choices in the greening of sponge cities, while alleviating urban waterlogging and minimizing the impact on residents’ lives.

Long-term effects of air pollution on daily outpatient visits for allergic conjunctivitis from 2013 to 2020: a time-series study in Urumqi, China

IntroductionThis study aimed to elucidate the effects of outdoor air pollution and allergic conjunctivitis and population-based lagged effects of air pollution.MethodsWe included data on six major air pollutants, PM10, PM2.5, carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3), and 3325 allergic conjunctivitis outpatient visits in Urumqi, northwest China, from 1 January 2013 to 31 December 2020. We developed quasi-Poisson generalized linear regression models with distributed lagged nonlinear models (DLNM), and single and multi-pollutant models were constructed to investigate single-day and cumulative lagged effects in detail.ResultsOur results confirmed that elevated PM10 and NO2 levels are significantly associated with increased allergic conjunctivitis outpatient visits with lags of 2 and 3 days respectively, and subgroup analyses further suggest that the effects of PM10 and NO2 on allergic conjunctivitis are more pronounced during the warm season. Women are more sensitive to PM10 exposure and the effect of air pollution on allergic conjunctivitis is influenced by age (e.g., infancy and older people).DiscussionOur work provides the first time-series study in Urumqi, the world's furthest inland city from the ocean. Further implementation of specific outdoor air pollution controls such as the burning of fossil fuels like coal, as well as special population protection policies remain necessary. Multicenter studies with larger sample sizes are needed.

Research on the spatial distribution and influencing factors of the maritime services: based on data from Chinese enterprises

ABSTRACT In the context of global maritime cluster development and the strategic evolution of port cities, the spatial distribution and determinants of Maritime Services (MSs) emerge as pivotal areas of inquiry. However, empirical analysis in this domain remains limited. To address this deficiency, our study meticulously processes and analyses data from Chinese Maritime Service Enterprises (MSEs) listed in the World Shipping Register Company until 2023, categorizing these enterprises into port-related, ship-related and maritime consulting enterprises. Utilizing instrumental variables and econometrics, our findings reveal that MSs in China predominantly aggregate in coastal cities, along major inland waterways, and within inland central cities, with a pronounced clustering near urban centers. This distribution is primarily influenced by two factors: firstly, geographic proximity to seaports and throughput levels markedly impacts the distribution, especially for port-related enterprises and ship-related enterprises. Secondly, the clustering of downstream supporting industries, shared labor pools and knowledge spillovers, which are essential elements of agglomeration economics, particularly affects maritime consulting enterprises. Such a pattern is also influenced by the broader business environment and governmental governance. This research not only clarifies existing disputes regarding the maritime industry’s spatial distribution but also offers insights for MSs development and the transformative planning of port cities.

Emission Factors, Chemical Composition and Ecotoxicity of PM10 from Road Dust Resuspension in a Small Inland City

Road dust resuspension in urban environments can contribute to high human exposure to metal(loid)s, polycyclic aromatic hydrocarbons, and other potentially toxic organic compounds. However, for many regions, information on loadings, emission factors and chemical profiles is lacking to accurately apply emission inventories and source apportionment models. In the present study, PM10 samples were collected with an in situ road dust sampler from eleven representative streets of Bragança, an inland city of the Iberian Peninsula, and were analysed for organic and elemental carbon by a thermal-optical technique, elemental composition by ICP-MS and ICP-OES, and ecotoxicity by a luminescence inhibition bioassay with Allivibrio fischeri. A global emission factor of 5.36 ± 2.35 mg veh−1 km−1 was obtained but in suburban areas the values reached twice the average. Total carbon accounted for 14.9 ± 6.8% of the PM10 mass, while element oxides represented the largest share (28.6 ± 18.7%). Very high enrichments were found for typical traffic-related elements such as Cu, Zn, S, Pb and Ni. The geochemical index Igeo further confirmed that road dust of the study region is extremely contaminated by elements mainly originated from tyre and brake wear. Although the total non-carcinogenic and carcinogenic risks associated with metal exposure were found to be low for both children and adults, the bioluminescence inhibition assay showed (eco)toxic responses for all samples, indicating that road dust resuspension may pose a significant human health and ecological threat.

Different roads take me home: the nonlinear relationship between distance and flows during China’s Spring Festival

Human mobility modelling has attracted scholarly attention from physics-based methods and social science explanatory approaches. However, there is limited knowledge of the nonlinear relationship of flows and distance in intercity mobility and regional differences in the nonlinear relationship. Focusing on China’s long-distance and large-scale mobility during the Spring Festival, this paper develops a framework to explain the nonlinear relationship. Using the Gradient Boosting Decision Tree (GBDT) model and Tencent Big Data, we find that there are three types of nonlinear relationships, namely plateau (almost zero distance decay parameter), drop (decreasing distance decay parameter) and rebound (increasing distance decay parameter after decreasing). The provincial differences also reveal that the nonlinear relationships depend on the domestic relative location and the intra-provincial urban system. This result shows that the cities in the coastal province enjoy a more inclusive spatial structure, which supports the migration from the periphery of the province. In contrast, the inland cities are concerned with embracing the migrants and settling them down.

The urban island: climatic suitability of Linepithema humile (Hymenoptera: Formicidae) and the role of cities in the invasion of the Western Palearctic

AbstractUrban environments often present environmental conditions that facilitate the introduction and establishment of nonnative and invasive species. These can expand their range into areas with unfavorable climates by taking advantage of the ecological and climatic homogenization of cities, bypassing the ecological barriers presented by the surrounding environment. One way to monitor the expansion of these species is using potential distribution models. We used as a model species the Argentine ant, Linepithema humile (Hymenoptera: Formicidae) whose invasion has caused serious consequences for biodiversity and economic losses worldwide. We used the average result of six different algorithms and used climatic variables and population density as a proxy for the urbanization level in the Western Palearctic to build the predictive model. The model indicates this ant prefers to inhabit areas with Mediterranean and Temperate Oceanic climates and that its suitability depends on two main factors: the continentality (temperature annual range) and the degree of urbanization. The species is predicted to be absent in areas with large temperature contrasts throughout the year, particularly in rural and peri‐urban areas (i.e. adjacent to urban areas) of inland regions. Conversely, the species has a predilection for coastal and urban areas where environmental conditions are attenuated by the influence of the sea or the “urban heat island” effect in the case of inland cities. In this sense, cities act as “bioclimatic islands” facilitating the establishment of the Argentine ant as a reservoir, enlarging its distribution into climatically nonoptimal areas, and promoting its future expansion in a scenario of global warming and socioeconomic change.

Genomic surveillance reveals low-level circulation of two subtypes of genogroup C coxsackievirus A10 in Nanchang, Jiangxi Province, China, 2015-2023.

In recent years, coxsackievirus (CV) A10 has been associated with increasing sporadic hand, foot, and mouth disease (HFMD) cases and outbreaks globally. In addition to mild symptoms such as pharyngitis and herpangina, CVA10-related complications or even fatality can occur. Currently, systematic phylogenetic studies of CVA10 are limited. In this study, we first explored the epidemiological and genetic characteristics of CVA10 in Nanchang, an inland southeastern city of China, based on the HFMD surveillance network from 2015-2023. Among 3429 enterovirus-positive cases, 110 (3.04%) were associated with CVA10, with a male-to-female ratio of 1.62. The median age of the CVA10 patients was 2.3 years (interquartile range, IQR 1.0-4.0), with 94.55% (104/110) of the patients aged less than 5 years. Phylogenetic analyses using the full-length VP1, 5'UTR, P1, P2, P3 sequences and near full-length genomes indicated that CVA10 strains (n = 57) isolated in Nanchang belonged to genogroup C; two strains identified in 2017 belonged to C1 subtypes clustered with strains from Vietnam, Madagascar, France and Spain; and the others belonged to C2 subtypes interdigitating with CVA10 isolates from mainland China, the United States and Australia. Through extensive analysis, we identified a rare F168Y mutation in epitope 4 of VP1 in a Madagascar strain of genogroup F and a Chinese strain of genogroup C. Based on Bayesian evolutionary analyses, the average nucleotide substitution rate for the VP1 gene of CV10 strains was 3.07×10-3 substitutions/site/year. The most recent common ancestor (tMRCA) of genogroup C was dated 1990.84, and the tMRCA of CVA10 strains from Nanchang was dated approximately 2003.16, similar to strains circulating in other regions of China, suggesting that the viruses were likely introduced and cryptically circulated in China before the establishment of the HFMD surveillance network. Recombination analysis indicated intertypic recombination of the Nanchang strain with the genogroup G strain in the 3D region. Given the shifting dominance of viral genotypes and frequent recombination events, the existing surveillance system needs to be regulated to enhance genomic surveillance efforts on a more diverse spectrum of genotypes in the future.

Spatiotemporal Patterns of Land Surface Temperature, Urban Heat Island, and Potential Heat Stress Risk Areas Assessment for Tropical Inland City and Coastal City in Thailand

Global warming and rapid urban growth, compounded by the urban heat island (UHI) effect, are posing substantial challenges for urban populations and ecological well-being due to increased heat stress risks. This study aimed to analyze the spatiotemporal patterns of land surface temperature (LST), UHI, and potential heat stress risk areas (PHSRA) in two distinct cities, an inland city, Nakhon Ratchasima, and a coastal city, Si Racha, during the summer. Geoinformatics techniques and Crichton’s Risk Triangle method were employed, using updated demographic data and Sentinel-3 data from 2017 to 2022. The findings indicate that the inland city daytime average LST values were higher than in the coastal city, while the opposite was true at nighttime. Additionally, high daytime UHI patterns in the inland city were observed on the outskirts, and nighttime UHI concentrated in the urban center. The coastal city exhibited a strong daytime and nighttime UHI compared to the inland city, with daytime UHI peaking in the inner area and nighttime UHI near the coastline. The PHSRA was categorized into five risk levels (very high: > 0.8, high: 0.8–0.6, moderate: 0.6–0.4, low: 0.4–0.2 and very low: ≤ 0.2). During the daytime the highest risk areas, the high and very high levels of PHSRA in the inland city (23.84%) were greater than those in the coastal city (16.46%). Conversely, at nighttime, the coastal city (16.46%) exhibited higher levels than the inland city (5.26%). In nighttime conditions, all levels of PHSRA occurred more significantly than during the daytime in these cities. Understanding the spatiotemporal variations in PHSRA is vital for pinpointing places at risk of heat stress accidents in summer. This data is a goldmine for city planners and healthcare authorities, helping them plan interventions and effective measures for the future.

Can the digital economy facilitate the optimization of industrial structure in resource-based cities?

With the continuous development of economy, resource-based cities in China are in urgent need of transforming and upgrading their industrial structures. This article utilizes panel data of 114 resource-based cities from 2011 to 2021 to explore the impact and mechanism of digital economy on optimizing and upgrading industrial structure. The findings, demonstrating a nonlinear relationship, reveal that digital economy promotes the advancement of the industrial structure in resource-based regions significantly. Technological innovation and financial development serve as the intermediary channel of facilitating the advancement of industrial structure in digital economy through intermediary effect analysis. Moreover, in terms of regional heterogeneity, digital economy is more effective in assisting inland resource-based cities in achieving advanced industrial structure compared to coastal areas in China.

Exploring the spatial spillover effects of Yangtze River Delta ports on urban economic growth.

The Yangtze River Delta (YRD) ports are pivotal in shaping the Yangtze River Economic Belt and advancing urban economies across China. This article utilizes panel data from 20 cities with ports in the YRD area, spanning from 2011 to 2020, using the spatial Durbin model to explore how these ports influence urban economic growth. The findings indicate that: (1) The YRD ports significantly contribute to economic growth in both the port cities and their surrounding areas, with the indirect impact on neighboring cities being more substantial than the direct effect on the cities themselves; (2) The beneficial spillover effects of the YRD ports on the economic growth of nearby cities vary in intensity over different spatial ranges, marked by distinct boundary effects and geographical attenuation. The influence extends up to approximately 110km; (3) Within the various elements impacting the economic growth of cities in the YRD, financial development prominently exhibits a threshold effect on urban economic growth; (4) Upon analyzing heterogeneity, inland and coastal port cities manifest divergent spillover effects, with inland port cities predominantly exerting a positive spillover on adjacent regions. Accordingly, in order to eventually achieve the shared prosperity of the region's economy, it is recommended that a strong top-level design be established and that efforts be made to transform the YRD region into a core region a diffusion and driving effect.

Ship deployment problem with green technology adoption for an inland river carrier under non-identical streamflow and speed limits

The maritime industry is currently experiencing a shift towards green corridors. The inland waterway is the main transportation corridor with a relatively low adoption of green technologies, which produces heavy air pollution in inland cities. This paper investigates the ship deployment problem for an inland river carrier considering the adoption of green fuel and green technologies for a given ship fleet. A non-linear programming (NLP) model is proposed to jointly optimize green technology adoption, sailing speed, and routing problems while considering two unique characteristics of inland river shipping, including the non-identical streamflow and the speed limits on each shipping leg. The analytical propositions reveal the optimal operation strategy of the inland river ship fleet, and a column generation-based algorithm is further designed to solve the proposed model. By jointly investigating the ship operation strategy and sulphur emissions, we find the following management insights: Firstly, the ship would have a lower willingness to invest in shore power (scrubber) if it installed scrubber (shore power). The higher streamflow and looser speed limits would reduce the spillover effect of green technology adoption. Secondly, emissions will spillover from ports to river legs if only shore power is provided. Our findings provide valuable insights for policymakers to promote complete green technology adoption to achieve comprehensive abatement of the entire inland river.

Assessing the impact of China Railway Express operations on the development of Chinese cities: China-Europe freight routes evolution and city development analysis

The operation of the China Railway Express (CRE) has diversified freight transportation between China and Europe, expanding the international freight channels in Chinese cities where CRE operates. However, the relationship between the evolution of China-Europe freight routes and the development of Chinese cities remains unclear. Therefore, we propose a potential model to assess the evolution of CRE routes and develop an indicator system to measure city sustainability. We employ a coupled coordination degree model (CCDM) and structural equation modeling (SEM) to determine the impact of CRE on the development of these cities. Findings reveal several key insights. Firstly, CRE has facilitated the expansion of China-Europe freight routes in Chinese cities, significantly enhancing the accessibility of China-Europe integrated inland transportation. Secondly, the growth of freight routes between China and Europe has exerted a substantial influence on the long-term development of Chinese cities, particularly inland cities. The positive relationship between route evolution and city development has strengthened over time. Lastly, the expansion of China-Europe freight routes indirectly contributes to the development of inland cities, primarily through stimulating innovation, industry scale, financial growth, and international trade. In contrast, coastal cities mainly benefit from the direct promotion of the international trade levels.

Effects of heat waves on ozone pollution in a coastal industrial city: Meteorological impacts and photochemical mechanisms

Surface ozone (O3) pollution triggered by extreme weather conditions is attracting increasing attention. Heat waves in summer of 2022 were chosen to explore the photochemical and meteorological impacts on O3 formation in the southeastern coastal industrial city of Quanzhou in China. The machine-learning (ML)-based weather normalization showed that the de-weathered O3 concentrations (increased by 6.69 μg m−3) in 2022 were higher than those from 2015 to 2021. Temperature is the most important variable (33.5%), followed by solar radiation (23.5%) and RH (10.1%), differing from the O3 pollution in inland cities. The Observation-Based Model (OBM) analysis results showed that hydroxyl radical (OH) was the predominant oxidant for daytime atmospheric oxidation capacity (AOC). And oxygenated volatile organic compounds (OVOCs), NO2, and CO were the dominant contributors to OH reactivity, accelerating the recycling of ROx radicals and O3 formation. The daytime reaction rate of HO2+NO during the O3 pollution episodes was 20.0 ppb h−1, accounting for 65% of the total O3 production. The contribution of RO2+NO to the O3 production enhanced the possibility of the MDA8h O3 exceeding the Air Quality Standard of China. This study improves the understanding of O3 formation mechanisms in a coastal industrial city during heat waves, and the elevated contributions of meteorological conditions to O3 pollution become more challenge for the reduction of anthropogenic emissions controll.

Health Risk Assessment of Road-Dust-Bound Heavy Metals via Ingestion Exposure from One Typical Inland City of Northern China: Incorporation of Sources and Bioaccessibility

Heavy metals in road dust pose potential health risks to humans, while oral bioaccessibility and sources are all important factors influencing this health risk. However, few prior studies have combined them for health risk analysis. In this study, road dust samples were collected from different geographical locations of Jinan (west area, WA; central area, CA; and east area, EA) to analyze the source-specific and bioaccessibility-based health risks of heavy metals. The mean concentrations of heavy metals in the three areas were CA > EA > WA, with Cd, Cu, Mn, Pb, and Zn exceeding their corresponding background values. A source analysis using a Positive Matrix Factorization (PMF) model showed that traffic emissions were the main source of heavy metals in the WA and CA, while industrial activities were the main source in the EA. The mean bioaccessibility of heavy metals extracted using the Solubility Bioaccessibility Research Consortium (SBRC) method followed the order of Cd (75.5%) > Zn (42.2%) > Mn (42.1%) > Pb (42.0%) > Cu (32.9%) > As (23.6%) > Ni (20.1%) > V (16.8%) > Cr (13.3%). According to the combined source analysis, traffic was the primary risk factor in the WA (54.5 and 58.3% of NCR and CR, respectively) and CA (61.8 and 51.2%), with solid waste being the main risk factor in the EA (41.9 and 51.3%). In oral bioaccessibility testing, lower non-carcinogenic (<1.0) and carcinogenic risks (<1 × 10−6) of heavy metals were observed than those based on the total metal content. More importantly, As (43.4%) was replaced by V (29.7%) as the main contributor to NCR. Source-specific and bioaccessibility-based health risk assessments can accurately identify priority pollutants and heavy metals in urban road dust that need to be controlled. This provides more effective and accurate urban environmental risk management recommendations for sustainable urban development and population health.

Regional Truck Travel Characteristics Analysis and Freight Volume Estimation: Support for the Sustainable Development of Freight

In the field of freight transport, the goal of sustainable development requires us to improve the efficiency of freight transport while reducing its negative impact on the environment, such as reducing carbon emissions and noise pollution. There is no doubt that changes in freight characteristics and volumes are compatible with the objectives of sustainable development. Thus, mining the travel distribution and freight volume of trucks has an important supporting role in the freight transport industry. In terms of truck travel, most of the traditional approaches are based on the subjective definition of parameters from the trajectory data to obtain trips for certain vehicle types. As for freight volume, it is mostly estimated through manual surveys, which are heavy and inaccurate. In this study, a data-driven approach is adopted to obtain trips from the trajectory data of heavy trucks. Combined with the traffic percentage of different vehicle types collected by highway traffic survey stations, the trips of heavy trucks are extended to all trucks. The inter-city and intra-city freight volumes are estimated based on the average truck loads collected at the motorway entrance. The results show a higher proportion of intra-city trips by trucks in port cities and a higher proportion of inter-city trips by trucks in inland cities. Truck loading and unloading times are focused in the early morning or at night, and freight demand in Shandong Province is more concentrated in the south. These results would provide strong support for optimizing freight structures, improving transportation efficiency, and reducing transportation costs.

Coupling Study of Green Finance and High-Quality Economic Development

Based on panel data from 16 prefecture-level cities in Shandong Province from 2012 to 2021, a comprehensive evaluation system for the development of green finance and high-quality economic development in Shandong Province was constructed. The entropy weight method was used to calculate the comprehensive index of both. The research shows that, temporally, from 2012 to 2021, the coupling degree between green finance development and high-quality economic development in the prefecture-level cities of Shandong Province was mostly at a high or relatively high level, with the coordination degree increasing year by year. However, the overall level remained low, with most cities in a state of mild or near imbalance. Spatially, only coastal cities such as Qingdao, Dongying, Weihai, and Rizhao achieved basic coordination, with the coordination degree of coastal cities being higher than that of inland cities. Among them, coastal cities mainly exhibited high-high or high-low types, while inland areas mostly showed low-low types, failing to form a good linkage effect.

Research on the spatiotemporal distribution and factors influencing intangible cultural heritage in Fujian Province from a multiscale perspective

The spatiotemporal distribution of intangible cultural heritage in Fujian Province, China, and the factors that influence it were explored using multiple spatial scales. The samples include five batches of Chinese national-level and six batches of Chinese provincial-level intangible cultural heritage items, totaling 554. The samples involve city-scale, county-scale, and traditional dwellings, and the analysis uses various methods, such as gravity migration theory and the GeoDetector model. The results show that, in terms of historical timescales, the moving trajectory of the center of gravity of the intangible cultural heritage distribution in Fujian Province involves reciprocation from north to south, and the center moves south in time from the pre-Qin period to the modern period. Spatially, intangible cultural heritage in Fujian Province forms an overall aggregate pattern, among which traditional skills fall into an aggregate pattern; five categories, including traditional drama, fall into an aggregate-random pattern; and four categories, including traditional medicine, fall into a random pattern. The traditional art category and other intensive distribution areas are located in coastal areas, and the traditional dance category is scattered in northwestern Fujian Province. Experiments on the factors influencing intangible cultural heritage distribution were conducted at the city and county levels. At the city level, human geography factors, such as the resident population, urbanization rate, and gross domestic product, have a greater influence on distribution. At the county level, the influence of physical geographical factors clearly increases. The dominant factors for coastal cities are the normalized difference vegetation index (NDVI), average precipitation, and coastline, and that for inland cities is elevation. From the perspective of categories, the dominant factors of traditional music and Quyi are human geography factors, and those of other types of intangible cultural heritage are the synergistic effects of physical geography and human geography. The conclusions of this study are helpful for systematically protecting and developing the intangible cultural heritage industry and improving research theories and methodological systems of the spatiotemporal distribution and mechanism influencing intangible cultural heritage.

Impact of Free Trade (Pilot) Zone Establishment on Urban Land Use Efficiency—Empirical Evidence from Cities in China

The establishment of the Free Trade (Pilot) Zone (FTZ) is a new attempt by China to embark on modern sustainable urban planning and governmental territorial management at the development stage of a high-quality economy. As urban lands serve as the limited resource foundation for civic production and livelihoods, enhancing land use efficiency becomes a key measure to facilitate metropolitan economies of high quality. Utilizing panel data from prefecture-level cities spanning from 2005 to 2021, this study constructs a multi-period difference-in-differences model to explore the impact of FTZs on urban land use efficiency (ULUE). The results indicate that FTZs can significantly enhance urban land use efficiency, with a more pronounced policy effect observed in central cities, inland cities, and cities with higher urbanization rates. Furthermore, the FTZs also demonstrate spatial spillover effects on urban land use efficiency. This study holds great significance for relevant government departments in formulating policies to optimize land resource allocation, promote FTZ development, and foster high-quality urban planning and territorial management.

Assessing the relationship between particulate matter concentration and property values in Spanish cities

In recent years, air pollution has become the leading cause of illness and premature deaths worldwide, with adverse impacts on human health, the environment, and the economy. This empirical study aims to investigate the relationship between air quality and property values with a focus on six Spanish cities. The study utilizes property prices as a variable and particulate matter concentration as an air quality indicator. Key findings indicate a significant correlation between particulate matter and property prices in seaside cities, revealing a discernible relationship. However, in inland cities, the observed correlation is notably weak and nonsignificant, resulting in a negligible association between the two variables. These results highlight the presence of additional characteristics that influence property values beyond air quality, particularly in areas where air quality is already deemed satisfactory. This research contributes valuable insights into the intricate interplay between air quality and property values by providing nuanced perspectives on urban planning and policy formulation.

Epidemiological survey and genetic diversity of Bartonella in fleas collected from rodents in Fujian Province, Southeast China

BackgroundFleas, considered to be the main transmission vectors of Bartonella, are highly prevalent and show great diversity. To date, no investigations have focused on Bartonella vectors in Southeast China. The aim of this study was to investigate the epidemiological and molecular characteristics of Bartonella in fleas in Southeast China.MethodsFrom 2016 to 2022, flea samples (n = 1119) were collected from 863 rodent individuals in seven inland and coastal cities in Southeast China. Flea species, region, gender, host species and habitat were recorded. The DNA samples from each individual flea were screened by real-time PCR for the Bartonella ssrA gene. All positive samples were confirmed by PCR based on the presence of the gltA gene and sequenced. The factors associated with Bartonella infection were analyzed by the Chi-square test and Fisher's exact test. ANOVA and the t-test were used to compare Bartonella DNA load.ResultsBartonella DNA was detected in 26.2% (293/1119) of the flea samples, including in 27.1% (284/1047) of Xenopsylla cheopis samples, 13.2% (5/38) of Monopsyllus anisus samples, 8.3% (2/24) of Leptopsylla segnis samples and 20.0% (2/10) of other fleas (Nosopsyllus nicanus, Ctenocephalides felis, Stivalius klossi bispiniformis and Neopsylla dispar fukienensis). There was a significant difference in the prevalence of Bartonella among flea species, sex, hosts, regions and habitats. Five species of Bartonella fleas were identified based on sequencing and phylogenetic analyses targeting the gltA gene: B. tribocorum, B. queenslandensis, B. elizabethae, B. rochalimae and B. coopersplainsensis.ConclusionsThere is a high prevalence and diversity of Bartonella infection in the seven species of fleas collected in Southeast China. The detection of zoonotic Bartonella species in this study, including B. tribocorum, B. elizabethae and B. rochalimae, raises public health concerns.Graphical