ObjectivePhlebotomus chinensis (P. chinensis) serves as the primary vector of visceral leishmaniasis, a persistent public health threat, and its suitable distribution range and expansion trends remain unclear.MethodsThis study integrated two sets of baseline data, with 24,281 specimens collected from 45 counties across six provinces through field surveys and extra records from 475 distribution sites collated via literature retrieval. Climate data with 19 bioclimatic variables and geographic data including elevation, slope, aspect and vegetation coverage were obtained from open-access online databases (data retrieval cutoff: 2023). The Maximum Entropy (MaxEnt) model was applied to simulate habitat suitability. The area under the receiver operating characteristic curve was used to evaluate model performance, and the Jackknife test was conducted to determine the relative importance of each environmental factor.ResultsThe MaxEnt model produced an outstanding AUC value of 0.917 ± 0.007, demonstrating robust predictive performance. Vegetation coverage emerged as the primary environmental driver, followed by the minimum temperature of the coldest month (bio_6), mean temperature of the driest quarter (bio_9), and annual precipitation (bio_12). The contemporary suitable habitat for P. chinensis on the Chinese mainland spans 2,295,360 km², constituting 23.91% of the total land area. Core suitable habitats concentrate in central Shanxi, northern and western Henan, southern Shaanxi and Gansu, southwestern Hebei, and northern Sichuan. Under the RCP4.5 scenario, the suitable distribution range will expand to 2,834,001 km² (29.52%) by 2050 and 2,934,104 km² (30.56%) by 2070. The centroid of current suitable habitats is situated in Dagui Town, Pingli County, Ankang City, Shaanxi Province (109.137665°E, 32.438831°N), with a northwestward shift of 112.37 km by 2050 and 100.15 km by 2070.ConclusionsThis study potentially delineates the suitable ecological niche of P. chinensis across the Chinese mainland, identifies key environmental drivers, and provides scientific references for regional risk assessment and targeted prevention measures.

Background:Mountain-type zoonotic visceral leishmaniasis (MT-ZVL) is undergoing rapid re-emergence in central China and demonstrates significant potential for further dissemination. The aim of this study was to provide information on optimal control strategies by estimating the disease's current distribution and potential for spread into new areas. Methods:We used a three-pronged approach: (1) active field surveillance in 57 potential-risk counties in 2022 to investigate the distribution of the Phlebotomus chinensis (P. chinensis) vector and canine infections based on serological positivity; (2) study of annual surveillance reports of P. chinensis distribution and canine infection in 42 counties in Henan, Shanxi and Beijing (2023-2024); and (3) passive surveillance via China's National Notifiable Disease Surveillance System (NNDSS) revealing 1137 human MT-ZVL cases for the 2019-2024 period. We constructed a database based on an innovative active/passive surveillance approach and applied the optimized ecological niche model based on incorporating environmental, biological (the P. chinensis vector and infectious canines) and socioeconomic covariates to predict the relative risk of transmission at the 1 × 1 km resolution across central China. Model performance was validated using 239 unique, geolocated human case occurrences (2022-2024). This allowed us to map the MT-ZVL risk and quantify the populations at-risk within stratified risk tiers. Findings:The field surveillance across 20 of 57 potential MT-ZVL risk counties captured 7552 P. chinensis specimens (mean density: 13.7 sandflies/trap/night), with a high peak in Jiexiu County, Shanxi Province (499.8). In 14 counties with confirmed P. chinensis presence, canine infections were recorded in 9 counties giving a mean seroprevalence of 2.7% (44/1648), with the highest proportion at 16.2% (21/130) seen in Yuzhou County, Henan Province. Annual surveillance reports confirmed P. chinensis presence in 24 of 42 monitored counties, with seropositive canines in two counties. The final training dataset included the recorded findings of 270 P. chinensis sandflies, 224 infected canines and 213 human case records. Extreme gradient boosting demonstrated superior predictive performance for human MT-ZVL infection risk, significantly outperforming benchmark models, with the area under the curve (AUC) of 0.950 (95% CI: 0.921-0.979) in internal validation and 0.913 (95% CI: 0.886-0.940) in external validation. Model performance was further validated by 88.3% of indigenous cases occurring within predicted high-risk zones. These high-risk zones were concentrated in hilly terrain along the Taihang, Lvliang and Qinling Mountains-primarily in central-southern Shanxi, Hebei-Shanxi border regions, eastern Shaanxi and north-western Henan. This study identified 117 high-risk or very high-risk counties with a combined population of 19.24 million. Medium-risk areas were found to encompass surrounding regions across Shanxi, Shaanxi, Henan, eastern Gansu, central-western Hebei and western/northern Beijing (87 counties; 12.07 million residents), while low-risk zones covered 87 counties in eastern Gansu, northern Sichuan, north-western Henan and central Hebei mountains (15.35 million residents). The optimized multi-source data-driven model exhibited robust predictive performance, identifying 291 at-risk counties threatening about 46.67 million residents. Interpretation:This study demonstrated MT-ZVL to be a significant public health threat with rapid expansion across central China. Key findings revealed unabated endemic transmission, with the presence of P. chinensis and infectious canines in non-endemic areas signifying new emerging foci. By the identification of specific regions at risk for MT-ZVL, an evidence base warranting heightened public health vigilance against potential transmission has been established. Surveillance for MT-ZVL in central China and targeted interventions are strongly recommended. Funding:This work was supported by the National Natural Science Foundation of China (No. 32161143036, No. 82473688), National Key Research and Development Program (2021YFC2300800, 2024YFC2310902), the Three-Year Initiative Plan for Strengthening Public Health System Construction in Shanghai (2023-2025) (No. GWVI-11.1-12).

Sand fly-borne visceral leishmaniasis (VL) has re-emerged in parts of North-central China, while conventional insecticidal control is constrained by the predominantly exophilic ecology of sand flies. Wolbachia-based approaches have shown field utility in medical vector control, but baseline data on Wolbachia infection and strain diversity in sand flies from VL resurgence settings in China remain limited. Sand flies were collected during 2023–2024 at sentinel sites located in VL resurgence areas across four provincial-level administrative regions in China (Beijing Municipality, Shanxi Province, Henan Province, and Inner Mongolia Autonomous Region). Wolbachia was detected and typed by PCR and sequencing of the Wolbachia surface protein (wsp) gene, followed by estimation of pool positivity and bias-corrected maximum likelihood estimation (MLE)-based individual infection prevalence, haplotype inference, and phylogenetic and haplotype-network analyses. Three sand fly species—Phlebotomus chinensis, Ph. smirnovi, and Sergentomyia squamirostris—were identified across the surveyed sites. Overall, 268 pools (10 individuals per pool; 2680 specimens) were screened for Wolbachia, and 194 pools were PCR-positive (72.4

Abstract Background Golden apple snails (Gastropoda: Ampullariidae: Pomacea) were introduced into China in the 1980s for aquaculture and have since become widespread agricultural pests across East Asia. In addition to their invasive impact, they are a key intermediate host of the rat lungworm Angiostrongylus cantonensis (Secernentea: Angiostrongylidae) in China, the causative agent of eosinophilic meningitis in humans. Methods We conducted a malacological survey of 55 freshwater sites across Shanghai and neighboring East China provinces to assess Pomacea distribution, genetic diversity, and A. cantonensis infection status. A total of 700 Pomacea snails were examined for A. cantonensis using traditional lung microscopy and molecular xenomonitoring (PCR and LAMP). Mitochondrial COI barcoding was performed on 200 individuals from 20 high-density sites to assess species composition and genetic diversity. Results Pomacea snails were found at 81.8% (45/55) of sites surveyed. No A. cantonensis infections were detected by microscopy or molecular assays. Genetic analyzes revealed three Pomacea species (P. canaliculata, P. maculata, and P. occulta) and nine distinct COI haplotypes. Pomacea canaliculata was the most common and genetically diverse species, with four unique haplotypes (H5–H8) occurring only in Shanghai, indicative of recent introductions. Overall, populations showed moderate haplotype diversity (Hd = 0.73) and population structure (F ST = 0.24). Conclusions Although no A. cantonensis infections were detected in the snails examined in this survey, these negative findings do not preclude the possibility of low-prevalence or newly emerging infections. The wide distribution and high genetic diversity of Pomacea populations across Shanghai and East China highlight that suitable hosts are already well-established, emphasizing the ongoing risk of parasite introduction and spread into currently nonendemic regions. Continued molecular surveillance, public awareness, and strengthened biosecurity measures remain essential to effectively manage invasive snail populations and mitigate future public health threats. Graphical abstract

IntroductionTicks are well-known ectoparasites and vectors responsible for transmitting a diverse range of pathogens, including viruses, bacteria, and protozoa, many of which pose substantial risks to public health and livestock. In recent decades, the incidence and diversity of tick-borne diseases have increased globally, with several novel tick-borne viruses (TBVs) being discovered.MethodsThis study aimed to characterize the virome of ticks collected from various locations in Shanghai, China, using next-generation sequencing (NGS). A total of 2,568 ticks belonging to three dominant species—Haemaphysalis flava, Haemaphysalis longicornis, and Rhipicephalus sanguineus sensu lato—were collected and analyzed through metagenomic sequencing.ResultsThe sequencing analysis identified 214 viral contigs classified into 32 viral families, including Chrysoviridae, Phenuiviridae, Partitiviridae, Nairoviridae, Dicistroviridae, Reoviridae, Botourmiaviridae, and Flaviviridae. Several TBVs with potential relevance to human and animal health, such as Cheeloo Jingmen-like virus (CJLV), Songling virus (SGLV), brown dog tick phlebovirus 1 (BDTPV1), brown dog tick phlebovirus 2 (BDTPV2), and Wuhan mosquito virus 1 (WMV1), were detected. Significant differences in virome composition among tick species based on geographical locations were also observed.DiscussionThese findings highlight the influence of environmental factors on viral diversity in ticks and underscore the need for ongoing surveillance of TBVs. Implementation of longitudinal virome monitoring across tick developmental stages in Shanghai will provide critical insights for early warning systems, disease prevention strategies, and public health interventions.

Angiostrongylus cantonensis, the causative agent of human eosinophilic meningitis, utilizes terrestrial and freshwater gastropods as intermediate hosts. However, the molecular mechanisms underlying these host-parasite interactions remain unclear. We applied four-dimensional label-free quantitative (4D-LFQ) proteomics to examine proteomic alterations in infected versus uninfected specimens of two intermediate snail hosts, Lissachatina fulica and Pomacea canaliculata. Differentially expressed proteins (DEPs) were identified, followed by Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. In infected Lissachatina, 36 proteins were upregulated and 104 downregulated, while in infected Pomacea, 94 were upregulated and 364 downregulated. GO analysis revealed 111 enriched terms linked to 71 DEPs in Lissachatina and 484 terms associated with 389 DEPs in Pomacea. KEGG pathway enrichment (Level 3) showed predominant downregulation, including 12 of 20 pathways in Lissachatina and 18 of 20 in Pomacea. Both species shared downregulation in essential pathways: ribosome, proteasome, aminoacyl-tRNA biosynthesis (genetic information processing); glycolysis/gluconeogenesis, pyruvate metabolism, sulfur metabolism (metabolic); and phagosome formation and endocytosis (immune-related). Protein-protein association (PPA) analysis identified conserved hub proteins, Tr-type G domain and T-complex chaperonins, indicating coordinated disruption of translational and proteostatic processes in both groups. Our findings suggest that A. cantonensis can modulate host immunity and metabolism, suppressing key protective responses in both gastropod hosts. This proteomic data may serve as a foundation for discovering biomarkers and designing interventions to disrupt the parasite's life cycle.

(1) Background: As a prominent zoonotic parasitic disease, fascioliasis threatens the sustainable development of animal husbandry and public health. Current research focuses mainly on individual species (parasite or intermediate host), neglecting systematic evaluation of the transmission chain and exposure risks to animal husbandry. Thus, comprehensive studies are urgently needed, especially in the ecologically fragile alpine region of the Qinghai-Tibet Plateau; (2) Methods: Distribution data of Radix spp. and Fasciola hepatica in the Qinghai-Tibet Plateau and adjacent areas were gathered to establish a potential distribution model, which was overlaid on a map of livestock farming in the region; (3) Results: The key environmental factors influencing Radix spp. distribution were temperature seasonality (21.4%), elevation (16.4%), and mean temperature of the driest quarter (14.7%). For F. hepatica, the main factors were elevation (41.3%), human footprint index (30.5%), and Precipitation of the driest month (12.1%), with all AUC values exceeding 0.9. Both species exhibited extensive suitable habitats in Qinghai and Tibet, with higher F. hepatica transmission risk in Qinghai than Tibet; (4) Conclusions: The significant transmission risk and its impacts on the livestock industry in the Qinghai-Tibet Plateau highlight the need for proactive prevention and control measures. This study provides a scientific foundation for targeted alpine diseases control, establishes an interdisciplinary risk assessment framework, fills gaps in high-altitude eco-epidemiology, and offers insights for ecological conservation of the plateau.

BACKGROUND:Triatoma rubrofasciata is an obligate hematophagous insect and a primary vector of Trypanosoma cruzi, the etiological agent of Chagas disease, with a widespread global distribution. In addition to Try. cruzi, T. rubrofasciata also serves as a vector for various other pathogens, including Try. lewisi, Try. conorhini, and Bartonella species. Despite its increasing epidemiological relevance in the transmission of multiple diseases, research on T. rubrofasciata remains limited. RESULTS:Differentially expressed genes (DEGs) were associated with growth, development, carbohydrate metabolism, and immunity. Notably, homeobox protein genes, including homeobox protein Nkx-6.2-like, homeobox protein abdominal-B isoform X1, homeobox protein Hox-A3-like, and Hox-B4-like, along with E3 ubiquitin protein ligase genes and sexual differentiation-related genes, such as male-specific lethal 1-like 1 isoform X3 (MSL), transformer-2 protein homolog beta-like isoform X2 (tra-2), and doublesex- and mab-3-related transcription factor A2-like (dsx), were highly expressed in the egg stage. Additionally, venom-related genes, including venom histidine phosphatase-like protein 1 and venom serine carboxypeptidase-like, were predominantly expressed in nymphal stages 4 and 5, while cytochrome P450 CYP425A1v2 exhibited high expression levels in the adult stages. Among these DEGs, we propose that homeobox protein genes, dsx, tra-2, and others may serve as candidate genes involved in growth, development, and sexual differentiation. This study provides valuable insights into gene expression dynamics during T. rubrofasciata development and establishes a foundation for future functional research on this species. CONCLUSIONS:In this study, we sequenced the complete developmental stages of T. rubrofasciata using HiSeq technology. Our findings offer novel insights into the molecular mechanisms underlying development and sex regulation in this species. Furthermore, the identified differentially expressed genes (DEGs) may serve as potential targets for innovative pest control strategies.

Background Chongming Island in China serves as a breeding and shelter point on the East Asian–Australasian Flyway. The resting frequency of migratory birds, abundance of mosquito populations, and the popular domestic poultry industry pose a potential risk of mosquito-borne zoonotic diseases. The aim of this study is to explore the role of migratory birds in the spread of mosquito-borne pathogens and their prevalent status on the island. Methods We conducted a mosquito-borne pathogen surveillance in 2021, in Chongming, Shanghai, China. Approximately 67,800 adult mosquitoes belonging to ten species were collected to investigate the presence of flaviviruses, alphaviruses, and orthobunyaviruses by RT-PCR. Genetic and phylogenetic analyses were conducted to explore the virus genotype and potential nature source. Serological survey was performed by ELISA to characterize Tembusu virus (TMUV) infection among domestic poultry. Results Two strains of TMUV and Chaoyang virus (CHAOV) and 47 strains of Quang Binh virus (QBV) were detected in 412 mosquito pools, with the infection rate of 0.16, 0.16, and 3.92 per 1000 Culex tritaeniorhynchus , respectively. Furthermore, TMUVs viral RNA was found in serum samples of domestic chickens and faecal samples of migratory birds. Antibodies against TMUV were detected in domestic avian serum samples, generally ranging from 44.07% in pigeons to 55.71% in ducks. Phylogenetic analyses indicated that the TMUV detected in Chongming belonged to Cluster 3, Southeast Asia origin, and most closely related to the CTLN strain, which caused a TMUV outbreak in chickens in Guangdong Province in 2020, but distant from strains obtained previously in Shanghai, which were involved in the 2010 TMUV outbreak in China. Conclusions We speculate that the TMUV was imported to Chongming Island through long-distance spreading by migratory birds from Southeast Asia, followed by spill over and transmission in mosquitoes and domestic avian species, threatening the local domestic poultry. In addition, the expansion and prevalence of insect-specific flaviviruses and its simultaneous circulation with mosquito-borne virus are worthy of close attention and further study.

目的 分析2021年全国内脏利什曼病的疫情状况,为制订防治策略提供科学依据.方法 收集2021年国家传染病报告信息管理系统报告的全国内脏利什曼病病例信息,剔除疑似病例、重复病例以及皮肤利什曼病病例,建立数据库.采用Microsoft Excel 2016软件对内脏利什曼病三间分布进行描述性流行病学分析.结果 2021年全国14个省(自治区、直辖市)的81个县共报告内脏利什曼病230例,其中犬源型流行区病例180例,野生动物源型流行区病例4例,人源型流行区病例1例,非流行区输入性病例45例.病例主要分布于山西(127例)、陕西(35例)和甘肃(20例)等3个省,报告病例数合计占全国报告病例总数的79.1％(182/230).全国44个县属于流行区,共报告本地感染病例185例;其余37个县属于非流行区,共报告输入性病例45例.其中,山西省平定县(33例)、阳泉市郊区(29例)、阳泉市矿区(18例)、襄汾县(10例)和陕西省韩城市(11例)为主要流行县,报告病例数占全国总病例数的43.9％(101/230).内脏利什曼病复燃流行县主要集中在甘肃省(秦州区、西和县)、山西省(尧都区、和顺县、陵川县、沁县、屯留区、昔阳县)和河南省(新安县、新密市),共报告本地感染病例10例.甘肃省玉门市为新发流行县,报告本地感染病例1例.内脏利什曼病发病高峰为4月份.男女病例比为1 ∶0.4.农民和婴幼儿报告病例数分别占总报告病例数的47.4％(109/230)和24.8％(57/230);≥15岁年龄组占73.5％(169/230).结论 我国内脏利什曼病呈低度流行态势,但流行区范围逐渐扩大,应加强监测和防控.

ObjectiveTo investigate the resistance to pyrethroids， beta-cyhalothrin and fenitrothion as well as the frequencies of kdr and ace⁃1 alleles in Anopheles sinensis from three geographical populations in Chongming District， Shanghai.MethodsThe contact tube method recommended by WHO was used to determine mosquito resistance. The frequencies of kdr and ace⁃1 alleles in adult mosquitoes were determined by PCR amplification. The correlation between the frequencies of kdr alleles and insecticide resistance was analyzed by linear regression method.ResultsThe mosquito population near natural reserve （NF） was sensitive to deltamethrin， and the mortality rate was 100.00% at 24 h. The mosquito population with intensive breeding farms （HX） showed resistance to deltamethrin and beta-cyhalothrin， and the 24 h mortality was 48.00 % and 57.50 %， respectively. The 24 h mortality rate of the mosquito population with urban-rural integration area （AS） with suspected resistance to deltamethrin and beta-cyhalothrin was 84.40% and 86.00%. The 24 h mortality rate to Fenitrothion was 55.67%. There were 3 mutations in kdr gene locus 1014， and 7 mutated genotypes were detected， mainly L1014/L1014F and L1014F/L1014F. The mutation frequency of kdr allele in HX population was the highest （52.68%）. There was one mutation at site 119 of ace⁃1 gene， and three genotypes were detected， most of which were G119S mutation. There was a significant negative correlation between the frequency of kdr resistance allele and the mortality rate of beta-cypermethrin in An.sinensis populations （r2=0.930，P=0.036）. There was a significant negative correlation between the frequency of ace⁃1 resistance allele and the mortality rate of fenitrothion in An. sinensis populations from four habitats （r2=0.996，P=0.038）.ConclusionThe mutation frequency of insecticide resistance allele is associated with the development of mosquito resistance level. Therefore， comprehensive monitoring of resistance levels of An.sinensis in Chongming area should be continued to provide a basis for local mosquito resistance management.

Ticks can carry and transmit a large number of pathogens, including bacteria, viruses and protozoa, posing a huge threat to human health and animal husbandry. Previous investigations have shown that the dominant species of ticks in Shanghai are Haemaphysalis flava and Haemaphysalis longicornis. However, no relevant investigations and research have been carried out in recent decades. Therefore, we investigated the bacterial communities and tick-borne pathogens (TBPs) in Haemaphysalis spp. from Shanghai, China. Ixodid ticks were collected from 18 sites in Shanghai, China, and identified using morphological and molecular methods. The V3–V4 hypervariable regions of the bacterial 16S rRNA gene were amplified from the pooled tick DNA samples and subject to metagenomic analysis. The microbial diversity in the tick samples was estimated using the alpha diversity that includes the observed species index and Shannon index. The Unifrac distance matrix as determined using the QIIME software was used for unweighted Unifrac Principal coordinates analysis (PCoA). Individual tick DNA samples were screened with genus-specific or group-specific nested polymerase chain reaction (PCR) for these TBPs and combined with a sequencing assay to confirm the results of the V3–V4 hypervariable regions of the bacterial 16S rRNA gene. We found H. flava and H. longicornis to be the dominant species of ticks in Shanghai in this study. Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria are the main bacterial communities of Haemaphysalis spp. The total species abundances of Proteobacteria, Firmicutes and Bacteroidetes, are 48.8%, 20.8% and 18.1%, respectively. At the level of genus analysis, H. longicornis and H. flava carried at least 946 genera of bacteria. The bacteria with high abundance include Lactobacillus, Coxiella, Rickettsia and Muribaculaceae. Additionally, Rickettsia rickettsii, Rickettsia japonica, Candidatus Rickettsia jingxinensis, Anaplasma bovis, Ehrlichia ewingii, Ehrlichia chaffeensis, Coxiella spp. and Coxiella-like endosymbiont were detected in Haemaphysalis spp. from Shanghai, China. This study is the first report of bacterial communities and the prevalence of some main pathogens in Haemaphysalis spp. from Shanghai, China, and may provide insights and evidence for bacterial communities and the prevalence of the main pathogen in ticks. This study also indicates that people and other animals in Shanghai, China, are exposed to several TBPs.

目的 调查上海地区不同地点、不同生境游离媒介蜱的种类及分布,为蜱媒疾病防制提供依据.方法 采用布旗法,于2021年4-7和9-11月在松江、黄浦、崇明、嘉定、宝山、静安、普陀和闵行区等13个调查点采集植被中的游离蜱;形态鉴定后扩增16SrRNA和细胞色素C氧化酶亚基Ⅰ(CO Ⅰ)基因序列,利用获得的序列鉴定蜱种并构建系统发育树.结果 共采获游离蜱1 937只,隶属2属3种,分别为血蜱属的褐黄血蜱、长角血蜱和扇头蜱属的微小扇头蜱,分别占采获总数的92.36％、6.66％和0.98％.山坡林地采集褐黄血蜱和微小扇头蜱2种400只,占20.65％;公园/景区采集褐黄血蜱和长角血蜱2种1 341只,占69.23％;农村荒地采集褐黄血蜱1种82只,占4.23％;城市绿地采集褐黄血蜱1种114只,占5.89％.系统进化树显示,采获的同一蜱种位于同一进化分支上.结论 上海地区不同生境中游离蜱共有3种,不同生境中蜱的种类和数量分布不同,褐黄血蜱为各类生境中的优势种.

WHAT IS ALREADY KNOWN ON THIS TOPIC?:Malaria is an infectious parasitic disease transmitted by the bite of Anopheles mosquitoes and is a serious threat to human health. Surveillance of malaria vectors is part of the integrated strategy for malaria elimination in China.WHAT IS ADDED BY THIS REPORT?:This research supplements the population distribution, density, and seasonal fluctuation of malaria vectors in the Anopheles surveillance sites from 2018 to 2020 in China.WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?:Continuous surveillance of malaria vectors is important for maintaining malaria-free status in China and for providing a scientific basis for risk assessment of malaria retransmission.