1.Trends in global burden due to visceral leishmaniasis from 1990 to 2021 and projections up to 2035
Guobing YANG ; Aiwei HE ; Yongjun LI ; Shan LÜ ; Muxin CHEN ; Liguang TIAN ; Qin LIU ; Lei DUAN ; Yan LU ; Jian YANG ; Shizhu LI ; Xiaonong ZHOU ; Jichun WANG ; Shunxian ZHANG
Chinese Journal of Schistosomiasis Control 2025;37(1):35-43
Objective To investigate the global burden of visceral leishmaniasis (VL) from 1990 to 2021 and predict the trends in the burden of VL from 2022 to 2035, so as to provide insights into global VL prevention and control. Methods The global age-standardized incidence, prevalence, mortality and disability-adjusted life years (DALYs) rates of VL and their 95% uncertainty intervals (UI) were captured from the Global Burden of Disease Study 2021 (GBD 2021) data resources. The trends in the global burden of VL were evaluated with average annual percent change (AAPC) and 95% confidence interval (CI) from 1990 to 2021, and gender-, age-, country-, geographical area- and socio-demographic index (SDI)-stratified burdens of VL were analyzed. The trends in the global burden of VL were projected with a Bayesian age-period-cohort (BAPC) model from 2022 to 2035, and the associations of age-standardized incidence, prevalence, mortality, and DALYs rates of VL with SDI levels were examined with a smoothing spline model. Results The global age-standardized incidence [AAPC = -0.25%, 95% CI: (-0.25%, -0.24%)], prevalence [AAPC = -0.06%, 95% CI: (-0.06%, -0.06%)], mortality [AAPC = -0.25%, 95% CI: (-0.25%, -0.24%)] and DALYs rates of VL [AAPC = -2.38%, 95% CI: (-2.44%, -2.33%)] all appeared a tendency towards a decline from 1990 to 2021, and the highest age-standardized incidence [2.55/105, 95% UI: (1.49/105, 4.07/105)], prevalence [0.64/105, 95% UI: (0.37/105, 1.02/105)], mortality [0.51/105, 95% UI: (0, 1.80/105)] and DALYs rates of VL [33.81/105, 95% UI: (0.06/105, 124.09/105)] were seen in tropical Latin America in 2021. The global age-standardized incidence and prevalence of VL were both higher among men [0.57/105, 95% UI: (0.45/105, 0.72/105); 0.14/105, 95% UI: (0.11/105, 0.18/105)] than among women [0.27/105, 95% UI: (0.21/105, 0.33/105); 0.06/105, 95% UI: (0.05/105, 0.08/105)], and the highest mortality of VL was found among children under 5 years of age [0.24/105, 95% UI: (0.08/105, 0.66/105)]. The age-standardized incidence (r = -0.483, P < 0.001), prevalence (r = -0.483, P < 0.001), mortality (r = -0.511, P < 0.001) and DALYs rates of VL (r = -0.514, P < 0.001) correlated negatively with SDI levels from 1990 to 2021. In addition, the global burden of VL was projected with the BAPC model to appear a tendency towards a decline from 2022 to 2035, and the age-standardized incidence, prevalence, mortality and DALYs rates were projected to be reduced to 0.11/105, 0.03/105, 0.02/105 and 1.44/105 in 2035, respectively. Conclusions Although the global burden of VL appeared an overall tendency towards a decline from 1990 to 2021, the burden of VL showed a tendency towards a rise in Central Asia and western sub-Saharan African areas. The age-standardized incidence and prevalence rates of VL were relatively higher among men, and the age-standardized mortality of VL was relatively higher among children under 5 years of age. The global burden of VL was projected to continue to decline from 2022 to 2035.
2.Structural and Spatial Analysis of The Recognition Relationship Between Influenza A Virus Neuraminidase Antigenic Epitopes and Antibodies
Zheng ZHU ; Zheng-Shan CHEN ; Guan-Ying ZHANG ; Ting FANG ; Pu FAN ; Lei BI ; Yue CUI ; Ze-Ya LI ; Chun-Yi SU ; Xiang-Yang CHI ; Chang-Ming YU
Progress in Biochemistry and Biophysics 2025;52(4):957-969
ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.
3.Spatiotemporal distribution of Aedes albopictus and its influencing factors in China from 2000 to 2019
Zerui JIAO ; Lei QU ; Duoquan WANG ; Yi ZHANG ; Shan LÜ
Chinese Journal of Schistosomiasis Control 2025;37(3):268-275
Objective To investigate the spatial distribution of Aedes albopictus in China at different time periods from 2000 to 2019, so as to provide insights into precise management of Ae. albopictus in China. Methods Data pertaining to the distribution of Ae. albopictus in China from 2000 to 2019 were collected through literature retrieval with terms of “Aedes albopictus”, “monitoring”, “survey”, “density”, “distribution”, and “outbreak” in national and international databases. The title and time of the publication, sampling sites, sampling time, mosquito capture methods, and mosquito species and density were extracted, and the longitude and latitude of sampling sites were obtained through Baidu Map. Meteorological element data at meteorological observation stations within China were obtained from the National Climatic Data Center of the United States, and the annual maximum temperature, annual minimum temperature, average temperature in January, average temperature in July, annual temperature range, daily temperature range and relative humidity were calculated and subjected to Kriging interpolation. Monthly cumulative precipitation grid data and monthly average temperature grid data with a resolution of 1 km for China from 2000 to 2019 were obtained from the National Tibetan Plateau Scientific Data Center, and the annual precipitation and annual average temperature were calculated cumulatively. Population density data in China from 2000 to 2019 were obtained from the WorldPop Hub, and the gross domestic product (GDP) in China was obtained from the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences. The above data were divided into 5-year intervals to calculate data during the periods from 2000 to 2004, from 2005 to 2009, from 2010 to 2014, and from 2015 to 2019. Ae. albopictus distribution data were modeled in China from 2000 to 2019 and during each period with the classification random forest (RF) model, to predict the distribution of Ae. albopictus across the country and analyze the distribution of Ae. albopictus based on the seven major climate zones in China. The performance of RF models was evaluated by accuracy, precision, recall, and area under the receiver operating characteristic curve (AUC), and the importance of each feature in the RF model was evaluated with mean decrease accuracy (MDA). Results A total of 1 191 Chinese publictions and 391 English publications were retrieved, among which 580 articles provided detailed data on the sampling sites of Ae. albopictus and specific sampling years, meeting the inclusion criteria. A total of 2 234 Ae. albopictus sampling sites were included in China from 2000 to 2019, and RF modeling results showed that the overall Ae. Albopictus distribution area was mainly found in southeastern and southwestern provinces of China from 2000 to 2019, with scattered distribution in coastal areas of northeastern provinces, such as Liaoning Province. The accuracy, precision, recall and AUC of the RF model were 0.915 to 0.947, 0.933 to 0.975, 0.898 to 0.978, and 0.902 to 0.932 for the distribution of Ae. albopictus at different time periods from 2000 to 2019. Among all features in the RF models, population density was the most contributing factor to the distribution of Ae. albopictus in China, followed by GDP, and all meteorological variables contributed relatively less to the predictive power of the RF model. In China’s seven major climate zones, Ae. albopictus was almost entirely distributed in the marginal tropical humid region, the north subtropical humid region, and the warm temperate semi-humid region. The combined distribution area of these three zones accounted for 100.0% of the national distribution area from 2000 to 2004, from 2005 to 2009, and from 2010 to 2014, and 99.9% from 2015 to 2019, and the proportion of Ae. albopictus distribution area in the warm temperate semihumid region increased gradually from 20.2% to 30.2%. Conclusions Ae. albopictus is mainly distributed in the southeastern and southwestern provinces of China and is greatly influenced by population and economic factors. The warm temperate semi-humid region in China is gradually becoming a hot spot for the distribution of Ae. albopictus.
4.Research progress in hydrogels in tissue engineering trachea
Wenxuan CHEN ; Yibo SHAN ; Fei SUN ; Zhiming SHEN ; Yi LU ; Jianwei ZHU ; Lei YUAN ; Hongcan SHI
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(08):1195-1199
In cases where a tracheal injury exceeds half the length of the adult trachea or one-third of the length of the child trachea, it becomes difficult to perform end-to-end anastomosis after tracheal resection due to excessive tension at the anastomosis site. In such cases, tracheal replacement therapy is required. Advances in tissue engineering technology have led to the development of tissue engineering tracheal substitutes, which have promising applications. Hydrogels, which are highly hydrated and possess a good three-dimensional network structure, biocompatibility, low immunogenicity, biodegradability, and modifiability, have had wide applications in the field of tissue engineering. This article provides a review of the characteristics, advantages, disadvantages, and effects of various hydrogels commonly used in tissue engineering trachea in recent years. Additionally, the article discusses and offers prospects for the future application of hydrogels in the field of tissue engineering trachea.
5.Construction and Application of An Animal Model of Respiratory Syncytial Virus Infection Based on Humanized IGF1R Mice
Xiaowei YANG ; Dan XIE ; Shuran LI ; Lei BAO ; Zihan GENG ; Xian LIU ; Mengyao CUI ; Yaxin WANG ; Shan CAO ; Xiaolan CUI ; Jing SUN ; Shanshan GUO
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(21):48-53
ObjectiveTo construct an animal model of respiratory syncytial virus(RSV)-infected pneumonia suitable for preclinical studies. MethodsThe virulence of RSV to the four cell lines was observed by cytopathic effect (CPE), and 50% tissue culture infective dose(TCID50) was calculated. Twenty BALB/c mice were randomly divided into a normal group and a model group. Six BALB/c-hIGF1R mice served as the humanized IGF1R model group. Except for the normal group, the other groups received intranasal RSV infection on days 1 and 3 to establish a viral pneumonia model. The efficacy of establishing an RSV-induced pneumonia animal model based on humanized insulin-like growth factor 1 receptor (IGF1R) mice was evaluated by measuring organ indices, peripheral blood lymphocyte percentages, pulmonary pathology and imaging, and pulmonary viral load. Additionally, ten BALB/c mice served as normal group, and thirty-two BALB/c-hIGF1R mice were randomly assigned to humanized IGF1R model group, ribavirin group (82.5 mg·kg-¹·d-¹), and high and low dose groups of Lianhua Qingwen (3.3 mg·kg-¹·d-¹ , 1.65 mg·kg-¹·d-¹), with 8 mice per group. The viral load in lung tissue was measured after ribavirin and Lianhua Qingwen intervention, and the model was applied to the evaluation of anti-RSV drugs. ResultsIn the lungs of the humanized IGF1R model group, large solid and diffuse ground-glass shadows were seen, and the lung volume was significantly increased (P<0.01). The lung index was significantly increased (P<0.01), and both the spleen index and thymus index were significantly decreased (P<0.01). The percentages of CD3+ and CD4+T cells were significantly decreased (P<0.05), and there was a large amount of inflammation and stasis in the perivascular area of the lung tissue, which was predominantly characterized by lymphocytes. The endothelium of blood vessels was partially detached, with a small number of eosinophils. After infecting BALB/c-hIGF1R mice with RSV, the expression of viral nucleic acids in the lung tissue of the mice was significantly increased, with significant differences compared with the normal group (P<0.01). The expression of viral nucleic acids in the ribavirin group and the high and low dose groups of Lianhua Qingwen was significantly reduced, with significant differences compared with the normal group (P<0.01). ConclusionHumanized IGF1R mice are more susceptible to respiratory SVC, and the animal model of RSV-infected pneumonia based on humanized IGF1R mice was successfully constructed, which is suitable for the evaluation of anti-RSV drugs.
6.Construction and Application of An Animal Model of Respiratory Syncytial Virus Infection Based on Humanized IGF1R Mice
Xiaowei YANG ; Dan XIE ; Shuran LI ; Lei BAO ; Zihan GENG ; Xian LIU ; Mengyao CUI ; Yaxin WANG ; Shan CAO ; Xiaolan CUI ; Jing SUN ; Shanshan GUO
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(21):48-53
ObjectiveTo construct an animal model of respiratory syncytial virus(RSV)-infected pneumonia suitable for preclinical studies. MethodsThe virulence of RSV to the four cell lines was observed by cytopathic effect (CPE), and 50% tissue culture infective dose(TCID50) was calculated. Twenty BALB/c mice were randomly divided into a normal group and a model group. Six BALB/c-hIGF1R mice served as the humanized IGF1R model group. Except for the normal group, the other groups received intranasal RSV infection on days 1 and 3 to establish a viral pneumonia model. The efficacy of establishing an RSV-induced pneumonia animal model based on humanized insulin-like growth factor 1 receptor (IGF1R) mice was evaluated by measuring organ indices, peripheral blood lymphocyte percentages, pulmonary pathology and imaging, and pulmonary viral load. Additionally, ten BALB/c mice served as normal group, and thirty-two BALB/c-hIGF1R mice were randomly assigned to humanized IGF1R model group, ribavirin group (82.5 mg·kg-¹·d-¹), and high and low dose groups of Lianhua Qingwen (3.3 mg·kg-¹·d-¹ , 1.65 mg·kg-¹·d-¹), with 8 mice per group. The viral load in lung tissue was measured after ribavirin and Lianhua Qingwen intervention, and the model was applied to the evaluation of anti-RSV drugs. ResultsIn the lungs of the humanized IGF1R model group, large solid and diffuse ground-glass shadows were seen, and the lung volume was significantly increased (P<0.01). The lung index was significantly increased (P<0.01), and both the spleen index and thymus index were significantly decreased (P<0.01). The percentages of CD3+ and CD4+T cells were significantly decreased (P<0.05), and there was a large amount of inflammation and stasis in the perivascular area of the lung tissue, which was predominantly characterized by lymphocytes. The endothelium of blood vessels was partially detached, with a small number of eosinophils. After infecting BALB/c-hIGF1R mice with RSV, the expression of viral nucleic acids in the lung tissue of the mice was significantly increased, with significant differences compared with the normal group (P<0.01). The expression of viral nucleic acids in the ribavirin group and the high and low dose groups of Lianhua Qingwen was significantly reduced, with significant differences compared with the normal group (P<0.01). ConclusionHumanized IGF1R mice are more susceptible to respiratory SVC, and the animal model of RSV-infected pneumonia based on humanized IGF1R mice was successfully constructed, which is suitable for the evaluation of anti-RSV drugs.
7.Cost-effectiveness analysis of insulin degludec and insulin aspart in Chinese patients with type 2 diabetes mellitus
Jiali QIN ; Yawen ZHANG ; Lei ZHANG ; Shan JIANG ; Xiaoyan YOU ; Xiaomei WANG ; Xianying WANG
China Pharmacy 2025;36(22):2809-2814
OBJECTIVE To evaluate the long-term cost-effectiveness of insulin degludec and insulin aspart (IDegAsp) in patients with type 2 diabetes mellitus (T2DM) in China. METHODS A cost-effectiveness analysis was conducted from the perspective of the Chinese healthcare system, using the CORE diabetes model to simulate long-term (20-year) health and economic outcomes. Baseline cohort characteristics and treatment effect data were derived from the CREATE study. The prices of glucose- lowering drugs were obtained from medical insurance payment standards and the average winning bid prices in the follow-up round of the specialized centralized procurement for insulin, while the daily dosages were derived from the CREATE study. The costs of complications and utility values were obtained from published literature, with a discount rate of 5%. One-way sensitivity analysis, scenario analysis, and probabilistic sensitivity analysis were performed to verify the robustness of the results. RESULTS Patients switching from previous once-daily basal insulin regimens to IDegAsp therapy gained an incremental 0.190 quality-adjusted life year (QALY) with direct medical cost savings of 42 163.58 yuan. For those switching from premixed insulin therapies, IDegAsp treatment provided 0.130 incremental QALY and reduced direct healthcare costs by 41 129.11 yuan. The outcome was significantly influenced by the discount rate and the cost of complications. Probabilistic sensitivity analysis and scenario analysis confirmed the robustness of these findings. CONCLUSIONS Switching from previous daily basal insulin or premixed insulin regimens to IDegAsp in Chinese patients with T2DM can improve patients’ long-term health outcomes and achieve cost savings, making it a more cost-effective treatment option.
8.Overview of the establishment of Shanghai twin birth cohort
Shan JIN ; Naisi QIAN ; Weixiao LIN ; Liping FANG ; Lei CHEN ; Bo FANG ; Tian XIA ; Chunfang WANG ; Huiting YU
Shanghai Journal of Preventive Medicine 2024;36(1):16-20
ObjectiveTo establish the Shanghai twin birth cohort (STBC) and analyze the effects of genetic factors, shared environment, and non-shared environment interactions on birth health and growth and development of newborns. MethodsBased on the population-wide birth cohort in Shanghai, a comprehensive survey was conducted on the families with double and multiple babies born after January 1, 2015 to collect information on birth health, growth and development, and the family environment of the babies. ResultsBy December 31, 2021, a total of 7 195 pairs (14 405 cases) of twins were successfully included in the STBC survey. The average birth length of twins was 47.2 cm and average birth weight was 2 465.3 g. Heterozygous twins accounted for 69.05% and preterm babies accounted for 57.07%. The average age of the mothers of twins was 31.82 years, and the average age of the fathers was 33.87 years, with more than 80% of the parents having a college degree or above. 44.50% of the mothers used assisted reproductive technologies, 7.40% had illnesses during pregnancy, and 15.90% were exposed to passive smoking during pregnancy. During the survey period, the average monthly increase in the length of the twin infants was 2.09 cm, and the average monthly weight gain was 0.53 kg. ConclusionThe incidence of adverse outcomes such as maternal cesarean section rate, preterm birth, and low birth weight is higher in the twin birth population. Information on birth health as well as growth and development in childhood and adolescence in the twin birth population is collected based on STBC, which can provide a solid data foundation for studying children’s chronic non-communicable diseases, psychological and behavioral disorders and other complex health problems caused by the combined effects of genetics and the environment.
9.Efficacy and Mechanism of Lutongning Granules in Treatment of Trigeminal Neuralgia Induced by Injection of Talc into Infraorbital Foramen of Model Rats Based on P2X7R-mediated Neuroinflammation
Qiyue SUN ; Shuran LI ; Shuangrong GAO ; Shanshan GUO ; Zihan GENG ; Lei BAO ; Ronghua ZHAO ; Jingsheng ZHANG ; Bo PANG ; Yingli XU ; Yu ZHANG ; Shan CAO ; Yaxin WANG ; Xiaolan CUI ; Bing HAN ; Jing SUN
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(15):56-63
ObjectiveTo evaluate the effectiveness of Lutongning granules in the treatment of trigeminal neuralgia in animal models and study its mechanism of action, so as to provide laboratory data support for the clinical application of Lutongning granules and precise treatment. MethodMale SD rats were randomly divided into normal group, model group, carbamazepine group (0.06 g·kg-1·d-1), high-dose Lutongning group (2.70 g·kg-1·d-1), and low-dose Lutongning group (1.35 g·kg-1·d-1) according to the stratified basic mechanical pain thresholds, with 10 rats in each group. A trigeminal neuralgia model of rats was prepared by injecting 30% talc suspension into the infraorbital foramen area of the rat. The drug groups were administered 10 mL·kg-1 of drugs by gavage after 2 h of modeling. The normal group and the model group were administered distilled water by gavage under the same conditions once a day for 10 consecutive days. Von Frey brushes were used to determine the mechanical pain threshold of rats. A fully automated blood and body fluid analyzer was employed to detect the blood routine of rats. Hematoxylin and eosin (HE) staining was utilized to detect the pathological changes in the trigeminal ganglion and medulla oblongata tissue. Transmission electron microscopy was used to scan the ultrastructure of the medulla oblongata tissue. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor (TNF)-α, neuropeptide substance P, and β-endorphins (β-EP) in the serum of rats, and Western blot was used to detect the protein expression levels of IL-1β, purinergic receptor P2X7 (P2X7R), and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK). ResultCompared with that in the normal group, the pain threshold of rats in the model group was significantly lower (P<0.01). The absolute value of neutrophils (NEUT#) and the percentage of neutrophils (NEUT) were significantly improved, and the percentage of lymphocytes (LYMPH) was significantly reduced (P<0.01). The serum levels of IL-1, IL-6, IL-8, and TNF-α were significantly increased (P<0.01). SP content in brain tissue was significantly increased, and β-EP content was significantly decreased (P<0.01). The relative protein expression of IL-1β, P2X7R, and p-p38 MAPK was significantly increased (P<0.05). HE staining and transmission electron microscopy results of medulla oblongata tissue revealed neuronal degeneration, mild proliferation of microglial cells, reduction in the number of myelinated nerves, and obvious demyelination. The trigeminal nerve fibers of rats were disarranged, and some nerve fibers showed vacuolization. Axons were swollen, and Schwann cells proliferated. Demyelination was observed. Compared with the model group, each administration group significantly increased the pain threshold of rats (P<0.05, P<0.01), reduced NEUT# and NEUT, and elevated LYMPH (P<0.05, P<0.01). The administration group significantly decreased the levels of IL-1, IL-6, IL-8, and TNF-α in serum and SP in brain tissue (P<0.01) and increased the level of β-EP (P<0.01). They significantly down-regulated the protein expression of IL-1β, P2X7R, and p-p38 MAPK(P<0.05, P<0.01) and significantly ameliorated the pathological changes in medulla oblongata tissue and trigeminal nerves of rats. ConclusionLutongning Granules had significant therapeutic effects on trigeminal neuralgia induced by injection of talc into the infraorbital foramen of model rats, and the mechanism may be related to amelioration of P2X7R-mediated neuroinflammation and inhibition of demyelination of myelinated nerves.
10.Molecular tracing of Biomphalaria straminea in China
Lei DUAN ; Lei QU ; Yunhai GUO ; Wenbiao GU ; Shan LÜ ; Yi ZHANG ; Xiaonong ZHOU
Chinese Journal of Schistosomiasis Control 2024;36(3):272-278
Objective To investigate the origin of Biomphalaria straminea in China, so as to provide insights into assessment of schistosomiasis mansoni transmission risk and B. straminea control. Methods Guanlan River, Dasha River, Shenzhen Reservoir, upper and lower reaches of Kuiyong River, and Xinzhen River in Shenzhen, China, were selected as sampling sites. Ten Biomphalaria samples were collected from each site, and genomic DNA was extracted from Biomphalaria samples. DNA samples were obtained from 15 B. straminea sampled from 5 sampling sites in Minas Gerais State, Pará State, Federal District, Pernambuco State, and Sao Paulo State in Brazil, South America. Cytochrome c oxidase I (COI) and mitochondrial 16S ribosomal RNA (16S rRNA) genes were sampled using the above DNA templates, and the amplified products were sequenced. The COI and 16S rRNA gene sequences were downloaded from GenBank, and the sampling sites were acquired. All COI and 16S rRNA gene sequences were aligned and evolutionary trees of B. straminea were created based on COI and 16S rRNA gene sequences to identify the genetic similarity and evolutionary relationship between B. straminea samples from China and South America. Results A total of 60 COI gene sequences with a length of 529 bp and 3 haplotypes were obtained from B. straminea sampled from China. There were 165 COI gene sequences of B. straminea retrieved from GenBank, and following alignment with the above 60 gene sequences, a total of 33 haplotypes were obtained. Phylogenetic analysis showed that the three haplotypes of B. straminea from China were clustered into one clade, among which the haplotype China11 and three B. straminea samples from Brazil retrieved from GenBank belonged to the same haplotype. Geographical evolution analysis showed that the B. straminea samples from three sampling sites along eastern coasts of Brazil had the same haplotype with China11, and B. straminea samples from other two sampling sites were closely, genetically related to China11. A total of 60 16S rDNA gene sequences with approximately 322 bp in length were amplified from B. straminea in China, with 2 haplotypes identified. A total of 70 16S rDNA gene sequences of B. straminea were captured from GenBank. Phylogenetic analysis showed that Biomphalaria snails collected from China were clustered into a clade, and the haplotype China64 and the haplotype 229BS from Brazil shared the same haplotype. The 49 16S rDNA gene sequences of B. straminea from 25 sampling sites in southern Brazil, which were captured from GenBank, were included in the present analysis, and the B. straminea from 3 sampling sites shared the same haplotype with China64 in China. Geographical evolution analysis based on COI and 16S rRNA gene sequences showed that B. straminea sampled from eastern coastal areas of Brazil shared the same haplotypes in two gene fragment sequences with Biomphalaria snails collected from China. Conclusions The Biomphalaria snails in China are characterized as B. straminea, which have a low genetic diversity. The Biomphalaria snails in China have a high genetic similarity with B. straminea sampled from eastern coastal areas of Brazil, which may have originated from the eastern coastal areas of Brazil.

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