Tropical diseases, the transmission of which is affected by multiple natural and social factors, pose a great challenge to global public health, notably in African countries. During the past several decades, China and African countries have continuously collaborated for the control of neglected tropical diseases and malaria, which has become an important part of global South-to-South cooperation and global health governance. This article reviews the history of China-Africa cooperation for tropical diseases control, summarizes the experiences and achievements over the past decade, analyzes the current challenges in the coopera tion, and proposes future recommendations. The China-Africa cooperation has achieved significant progress in the control of tropical diseases, such as malaria, schistosomiasis, and filariasis, and established a China-Africa cooperation network for tropical diseases control. Through the "Three-Step" strategy of China-Africa cooperation, the effectiveness of China's integrated control strategies has been validated in Africa, and the application of China's tropical disease control technologies has been promoted in African disease-epidemic countries. Currently, China-Africa collaboration, however, still experiences multiple realistic challenges, such as insufficient resources, difficulty in technology transfer, and weak primary healthcare systems. In the future, both sides are recommended to further strengthen policy coordination, deepen technological cooperation, innovate cooperation models, aiming to continuously promote the high-quality development of China-Africa cooperation for tropical diseases control.

Objective To evaluate the effectiveness of schistosomiasis surveillance in Jiangsu Province during the stage moving from transmission control to transmission interruption, and to analyze the current risk and challenges, so as to provide the evidence for achieving the target of schistosomiasis elimination. Methods Schistosomiasis surveillance data were collected from Jiangsu Province from 2012 to 2024, and the endemic areas, Schistosoma japonicum infections in humans and livestock, Oncomelania hupensis snail distribution and implementation of integrated interventions were descriptively analyzed. In addition, the trends in areas with snails, seroprevalence of human S. japonicum infections and numbers of advanced schistosomiasis cases were assessed using a Joinpoint regression model. Results The endemic areas of schistosomiasis continued to shrink in Jiangsu Province from 2012 to 2024, with the number of schistosomiasis-eliminated counties (cities, districts) increasing from 53 (75.71%) to 63 (96.92%), and interruption of schistosomiasis transmission was achieved across the province. A total of 4 600 300 person-times were tested for serum antibodies against S. japonicum, with 28 719 person-times positive detected; and 616 500 person-times were tested S. japonicum infections among local residents in Jiangsu Province from 2012 to 2024, with only 3 egg-positives detected, and no egg-positives found since 2017. A total of 187 600 herd-times were tested for schistosomiasis in livestock, and no S. japonicum infections were found. O. hupensis snail survey was performed covering 1 018 408.97 hm², and a total of 35 556.35 hm² was found with snail-infested habitats, including 174.40 hm2 of emerging snail-infested habitats. A total of 1 102 800 O. hupensis snails were identified for S. japonicum infections, and no infections were found. The areas of snail-infested habitats appeared a tendency towards a rise in Jiangsu Province from 2019 to 2023 (APC = 23.67%, P < 0.05), and the actual areas of snail-infested habitats appeared a tendency towards a decline from 2012 to 2015 (APC = −22.77%, P < 0.05), and towards a rise from 2015 to 2023 (APC = 9.76%, P < 0.01). The seroprevalence of anti-S. japonicum antibodies appeared a tendency towards a decline among residents in Jiangsu Province from 2017 to 2023 (APC = −14.92%, P < 0.01). In addition, the number of newly diagnosed advanced schistosomiasis cases appeared a tendency towards a decline from 2012 to 2024 (APC = −12.02%, P < 0.01), and the numbers of advanced schistosomiasis patients requiring treatment showed a tendency towards a decline from 2012 to 2021 (APC = −10.56%, P < 0.01) and from 2021 to 2023 (APC = −20.06%, P < 0.01). Conclusions Great progresses had been achieved in schistosomiasis control in Jiangsu Province following transmission control, and transmission interruption had been achieved; however, there are still snail-infested habitats. High-intensity surveillance and integrated control are required to be maintained to advance the achievement of the target of schistosomiasis elimination in Jiangsu Province.

Objective To examine the impact of extreme temperature and drought stress on the survival of Bulinus globosus, so as to provide the theoretical evidence for the genomic research of Bulinus in absence of reference genes. Methods B. globosus snail samples were collected from Kiwani Shehia in Pemba Island, Zanzibar, Tanzania, and offspring snails were obtained through laboratory breeding and reproduction. A total of 120 10-week-old B. globosus snails from the same generation were selected and randomly assigned into four groups, including the high-temperature drought (HD) group, normal temperature drought (D) group, low-temperature drought (LD) group, and the control (C) group, of 30 snails in each group. Snails in HD, D, and LD groups were placed in beakers containing dry soil at the bottom and subsequently housed in climate chambers at 35, 26 ℃, and 10 ℃, respectively, while snails in Group C were maintained in 500 mL petri dishes containing dechlorinated tap water at 26 ℃. Following 3 days of breeding, living snails in each group were collected, and soft tissues were dissected and isolated. Total RNA was extracted from snail soft tissues for library construction, followed by high-throughput sequencing on the Illumina HiSeq 4000 sequencing system. De novo transcriptome assembly was performed using the Trinity software, and the longest transcripts were selected as unigenes. Gene functional annotations of unigenes were conducted using the Diamond software against Gene Ontology (GO) knowledgebase, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database, NCBI non-redundant (NR) protein sequences database, Protein Family (Pfam) database, and UniProtKB/Swiss-Prot (Swiss-Prot) knowledgebase. GO and KEGG enrichment analyses of differentially expressed genes (DEGs) were performed using the topGO and clusterProfiler software, respectively. In addition, four relevant genes were selected for validation using a real-time quantitative PCR (qRT-PCR) assay to verify the reliability of transcriptome sequencing results. Results Following 3 days of breeding, there were 7, 20, 28, and 30 survival B. globosus snails in HD, LD, D, and C groups, with corresponding survival rates of 23.33% (7/30), 66.67% (20/30), 93.33% (28/30), and 100.00% (30/30), respectively (χ² = 52.72, P < 0.001). De novo transcriptome assembly generated 176 942 unigenes, with annotation rates of 0.98%, 13.49%, 26.46%, 12.48%, and 14.39% against GO knowledgebase, KEGG pathway database, NR protein sequences database, Pfam database, and Swiss-Prot knowledgebase, respectively. There were 33 up-regulated and 72 down-regulated genes in Group D, 483 up-regulated and 815 down-regulated genes in Group HD, and 245 up-regulated and 172 down-regulated genes in Group LD relative to in Group C. Following removal of overlapping genes across groups and unmatched genes, 11 candidate genes were identified. GO and KEGG analyses revealed 3 heat shock protein (HSP)-related DEGs in these 11 candidate genes, which were annotated as HSP12.2, HSP70, and HSP20 genes and were all significantly up-regulated in each treatment group. Three immune and nervous system-related DEGs were identified, and were all significantly down-regulated in each treatment group, which were involved in the neural cell adhesion molecule L1-like protein pathway, fibrinogen binding protein pathway, and leukocyte elastase inhibitor-like protein pathway. qRT-PCR assay quantified that the expression trends of four genes related to temperature and drought stress across different treatment groups were highly consistent with transcriptome sequencing data. Conclusion The survival rate of B. globosus significantly reduces under combined stresses of extreme temperature and drought, possibly due to an imbalance in its cellular homeostasis regulatory system.

Objective Objective To analyze the potential spatial factors affecting the genetic differentiation of Oncomelania hupensis robertsoni in Yunnan Province. Methods A total of 13 administrative villages were selected from schistosomiasis-endemic areas of Yunnan Province as O. hupensis snail sampling sites. At least 200 snails were collected in each site, and the spatial variable data of each site were recorded, including longitude, latitude and altitude. Thirty active and Schistosoma japonicum uninfected O. hupensis snails were selected from each sampling site by means of the crawling method and the cercarial shedding method. Genomic DNA was extracted from O. hupensis snails. Following PCR amplification, purification of PCR amplification products and sequencing, the gene sequences of O. hupensis snail samples were spliced and edited using the DNAstar software and the NCBI database to yield the complete mitochondrial sequences of O. hupensis snails at each sampling site, and the mitochondrial genetic distance matrix of O. hupensis robertsoni was calculated at each sampling site. The geographical coordinates of each sampling site were marked using the software ArcGIS 10.2, and the straight-line geographical distance between each sampling site was calculated. The altitude difference, longitude difference and latitude difference between each sampling site were calculated using the Excel software, and the correlation between the mitochondrial genetic distance matrix of O. hupensis robertsoni and each spatial variable matrix was examined by using the Mantel test at 13 sampling sites in Yunnan Province. Results Among the 13 O. hupensis snail sampling sites in Yunnan Province, the largest mitochondrial genetic distance of O. hupensis robertsoni snail populations was seen between Anding Village, Nanjian Yi Autonomous County and Caizhuang Village, Midu County (26.244 2), and the largest geographical distance was seen between Dongyuan Village, Gucheng District and Cangling Village, Chuxiong County (272.64 km). The highest altitude difference was seen between Anding Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1 086.10 m), and the largest longitude difference was found between Qiandian Village, Eryuan County and Cangling Village, Chuxiong County (1.86°), while the largest latitude difference was measured between Leqiu Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1.81°). In addition, the mitochondrial genetic distance of O. hupensis robertsoni snail populations was positively correlated with altitude at 13 snail sampling sites in Yunnan Province (r = 0.542 8, P < 0.001), and showed no significant correlations with geographical distance (r = 0.093 4, P > 0.05), longitude (r = −0.199 5, P > 0.05) or latitude (r = 0.205 7, P > 0.05). Conclusion Altitude may be a potential spatial factor affecting the genetic differentiation of O. hupensis robertsoni in Yunnan Province.

Objective To construct an index system for assessment of schistosomiasis transmission risk following natural disasters such as rainstorms, floods, earthquakes, mudslides, and landslides, so as to provide insights into rapid identification of schistosomiasis transmission risk post-disasters and formulation of targeted schistosomiasis control strategies. Methods An initial framework for the index system for assessment of schistosomiasis transmission risk following natural disasters was drafted through literature review, brainstorming, and focus group discussions. Two rounds of expert correspondence consultations were conducted using the Delphi method to refine and finalize the system, and the degrees of expert activeness, authority and endorse ment, and consensus were evaluated. In addition, the weights of each index were calculated using the analytic hierarchy process. Results A total of 18 experts participated in the consultation. The expert positive coefficients were 100.00% and 94.44% for two rounds of consultations, with authority coefficients of 0.92 and 0.94, respectively. The coefficients of coordination on the index importance, rationality and operability were 0.209, 0.185, 0.222 and 0.407, 0.214, 0.257 for two rounds of consultations, respectively, and all consistency tests were statistically significant (χ² = 246.771 to 505.278, all P values < 0.001). Following two rounds of expert consultations, an index system consisting of 6 first-level indicators, 15 second-level indicators, and 49 third-level indicators was ultimately constructed. In terms of first-level indicators, “disaster situation”, “previous epidemics”, “healthcare guarantee”, “response capacity” and “emergency recovery” had the highest weights, each at 18.18%. Regarding second-level indicators, “Schistosoma japonicum infections in animals”, “S. japonicum infections in snails” and “medical treatment” had the highest weights, each at 7.35%. In terms of third-level indicators, ten items had the highest weights, including “identification of schistosomiasis cases”, “detection of S. japonicum infections in wild feces”, “detection of S. japonicum infections in snails”, “reserves of schistosomiasis diagnostic/testing reagents and consumables”, “reserves of chemotherapy agents for human and animal schistosomiasis”, “reserves of cercariacides”, “periodical surveillance on schistosomiasis”, “identification of schistosomiasis transmission risk and timely response”, “normal provision of diagnosis and treatment services” and “post-disaster schistosomiasis surveillance”, each at 2.40%. Conclusion A scientific, systematic, and practical index system has been constructed for assessment of schistosomiasis transmission risk following natural disasters, which may provide insights into rapid post-disaster identification of schistosomiasis transmission risk, formulation of targeted schistosomiasis control strategies and optimization of resource allocation.

Objective To analyze Chinese and English publications pertaining to Oncomelania hupensis control from 2005 to 2024, so as to decipher the research status and hotspots of O. hupensis control. Methods Chinese and English publications pertaining to O. hupensis control from 2005 to 2024 were retrieved in the Web of Science Core Collection Database and China National Knowledge Infrastructure. The annual number of publications was analyzed from 2005 to 2024, and the author and institution cooperation networks were mapped using the software CiteSpace 6.3.1. Keywords were extracted from publications to map the co-occurrence, burst and timeline of keywords to identify the research hotspots of O. hupensis control. Results A total of 158 English publications and 771 Chinese publications were included for bibliometric analyses. The overall output of English publications was relatively small from 2005 to 2024, the annual average publication was 7.90 publications. Parasites & Vectors was the most productive journal by the number of publications (21 publications). The three most productive authors included Li Shizhu (24 publications), Zhou Xiaonong (13 publications), and Yang Kun (12 publications), and the three most productive institutions included Chinese Center for Disease Control and Prevention (49 publications), the WHO (27 publications), and Fudan University (25 publications). The annual average number of Chinese publications was high from 2005 to 2015 (57.73 publications), and reduced to 15.11 publications during the period from 2016 to 2024, with Chinese Journal of Schistosomiasis Control as the most productive journal (241 publications). The three most productive authors included Wang Wanxian (18 publications), Sun Qixiang (16 publications), and Dai Jianrong (16 publications), and the three most productive institutions included Jiangsu Institute of Parasitic Diseases (55 publications), Chinese Center for Disease Control and Prevention (47 publications), and Hubei Uni-versity (38 publications). Among the 158 English publications, molluscicidal effect, climate change, geographic information, biological control, machine learning were current research hotspots, and the Yangtze River and elimination were emerging research hotspots. Among the 771 Chinese publications, molluscicidal effect, niclosamide, comprehensive management, molluscicide, effectiveness evaluation, marshland, and endophyte were current research hotspots, and the future research hotspots shifted to molluscicidal effect and pyriclobenzuron. Conclusions Limited attention is paid to the research on O. hupensis control across the world. The Yangtze River, elimination, molluscicidal effect, and pyriclobenzuron may be future research hotspots. High attention is recommended to be paid to the research on O. hupensis control, and development of diverse approaches for O. hupensis control is of urgent needs. We should continue to attach importance to the control research of O. hupensis and strengthen the exploration of diverse snail extermination and control methods.

Background Aluminum (Al) is a lightweight metal that is widely present in the environment and the human body. It has been documented to cause various adverse health effects including the suppression of humoral immunity. Objective To investigate the role of oxidative stress in Al-induced humoral immunity suppression and to evaluate the possible protective effects of iron supplementation on this process. Methods Adult C57BL/6J mice were exposed to Al at concentrations of 0, 200, or 800 μg·mL⁻¹ via drinking water for three consecutive months. The expression of major histocompatibility complex class Ⅱ (I-A), proliferating cell markr-67 (Ki-67), and 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) in splenic B cells was evaluated through flow cytometry. Splenic B cells from the mice treated with 800 μg·mL⁻¹ Al or the control were sorted and treated in vitro with glutathione (GSH), N-Acetyl-L-cysteine (NAC), or a control vehicle. After 24 h, the expression of I-A was evaluated; and the hydroxyl radical (·OH)-generating potential, ·OH production, malondialdehyde (MDA) production, and iron content were assessed using commercial kits. Sixteen mice treated with 800 μg·mL⁻¹ Al received an intravenous injection of either a ferric chloride solution containing 0.3 g·L⁻¹ iron or a 0.9% sodium chloride solution, while eight control mice received 0.9% sodium chloride solution; the injection volume was 0.1 mL per mouse. Two and a half days after injection, I-A and Ki-67 expressions, ·OH-generating potential, ·OH production, and MDA production in splenic B cells were measured; and the concentrations of serum immunoglobulin (Ig) M and IgG were measured through (enzyme-linked immunosorbent assay) ELISA. The splenic B cells sorted from untreated mice were exposed to 0, 12.5, 25, or 50 μg·L⁻¹ Al in vitro. The splenic B cells treated with 50 μg·L⁻¹ Al and the splenic B cells sorted from 800 μg·mL⁻¹ Al-treated mice were additionally treated with GSH and NAC in vitro. The iron supplementation groups, which included the 50 μg·L⁻¹ Al-treated group and splenic B cells sorted from 800 μg·mL⁻¹ Al-treated mice, were treated with a culture medium containing 30 μmol·L⁻¹ iron in vitro. I-A and Ki-67 expressions, ·OH-generating potential, ·OH production, and MDA production in B cells were detected after a 24-h treatment period. Results In the in vivo mouse model, exposure to 800 μg·mL⁻¹ Al significantly inhibited the I-A and Ki-67 expressions (P<0.05), increased DCFH-DA expression and ·OH-generating potential (P<0.05, P<0.01), decreased iron content (P<0.01) and ·OH and MDA production (P<0.01, P<0.001) of splenic B cells, as well as serum IgM and IgG concentrations (P<0.05, P<0.01) in the mice. Exposure to 200 μg·mL⁻¹ Al showed a tendency to decrease the I-A and Ki-67 expressions, and to increase the DCFH-DA expression in splenic B cells, but these differences were not significant. In the in vitro splenic B-cell model, Al (12.5, 25, and 50 μg·L⁻¹) inhibited I-A and Ki-67 expressions (P<0.05, P<0.01) across all concentrations; 50 μg·L⁻¹ Al increased the ·OH-generating potential (P<0.05), and decreased ·OH and MDA production (P<0.01, P<0.05) in B cells. Treatment with GSH and NAC further suppressed I-A expression (P<0.05) in B cells. Iron supplementation increased the ·OH and MDA production (P<0.05), restored I-A and Ki-67 expressions (P<0.05, P<0.01) in B cells, and elevated the serum IgM and IgG concentrations (P<0.05) in Al-treated mice. Conclusion Al suppresses humoral immunity and ·OH production in B cells. The underlying mechanism may involve the decreased iron content and the subsequent retardation of the Fenton reaction in B cells. Supplementing with iron can restore the Fenton reaction in B cells and potentially reverse Al-induced impairment of humoral immunity.

Background Co-exposure to noise and microwave radiation occurs frequently. The central nervous system has been identified as a sensitive target organ for both noise and microwave exposure individually, and the underlying mechanisms remain poorly understood. The specific biological effects resulting from co-exposure to these two factors have yet to be fully elucidated. Objective To clarify the effects of co-exposure to noise and microwave on neurobehavior and hippocampal tissue structure, and to explore the underlying mechanism through the assessment of serum cytokines. Methods C57BL/6N mice were selected and randomly assigned to a blank control group, a noise group, a microwave group, and a combined noise & microwave exposure group. To establish the exposure models, the noise group was subjected to broadband noise at 100 dB for 2 h, while the microwave group received radiation at a central frequency of 9.375 GHz with an average power density of 12 mW·cm⁻² and a specific absorption rate of 2.58 W·kg⁻¹ for 15 min. Open field and tail suspension tests assessed anxiety-like emotional behaviour; novel object recognition and Y-maze tests evaluated cognitive function. Histological changes in hippocampal tissue were examined using haematoxylin and eosin (HE) staining, and Nissl staining under light microscopy. Serum cytokine levels were measured using radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). Results After 3 d of exposure, the noise, microwave, and combined exposure groups showed significant reductions in exploration frequency, duration, and distance within the central zone of the open field test compared to the control group (P < 0.01); the combined exposure group exhibited increased ratios of peripheral-to-central exploration time and distance (P < 0.05). After 7 d of exposure, compared with the control group, the noise group maintained a decrease in central zone exploration time (P < 0.01), while the combined exposure group showed persistent decline across all central zone metrics (P < 0.05) and elevated peripheral-to-central ratios (P < 0.05); compared to the microwave group, the combined exposure group showed significant less time in the central zone (P < 0.05) and higher peripheral-to-central ratios (P < 0.05). Regarding behaviour and cognition, compared with the control group, the combined exposure group showed increased immobility time in the tail suspension test after 3 d of exposure (P < 0.01). At this interval, all exposure groups demonstrated reduced frequency and duration of novel object recognition (P < 0.05), with the combined exposure group showing a marked decrease in novel arm exploration time (P < 0.01). After 7 d of exposure, compared with the control group, the noise group showed reduced novel object recognition frequency (P < 0.05), and both the noise and microwave groups exhibited decreased novel arm exploration time (P < 0.05). Pathological alterations including an increased number of hyperchromatic nuclei and depleted Nissl bodies were observed in the CA3 and DG regions across all exposure groups with the most severe lesions observed in the combined exposure group. Serum levels of central nervous system-specific protein β (S-100β), glial fibrillary acidic protein (GFAP), and corticosterone (CORT) were significantly elevated in all exposure groups compared with the control group (P < 0.05). Aquaporin-4 (AQP4) levels increased in the combined exposure group (P < 0.05), while CXC chemokine ligand 10 (CXCL10) levels rose in both the noise and combined groups compared with the control group (P < 0.05). Specifically, S-100β and CXCL10 levels in the combined exposure group were higher than those in the microwave group (P < 0.05); moreover, levels of S-100β, GFAP, CORT, AQP4, and CXCL10 in the combined exposure group were significantly higher than those in the noise group (P < 0.05). Conclusion Combined exposure to noise and microwave radiation induces pathological changes in the hippocampus of mice, increases levels of serum stress hormones and neuro-specific biomarkers. These impairments are more severe than those observed following single-factor exposure. The underlaying mechanism may be related to systemic stress response, neuronal damage, astrocyte activation, and changes in blood-brain barrier permeability, leading to emotional behavioral abnormalities and cognitive decline.

Background Climate change poses a significant threat to public health. In China, relevant health intervention research is still in its early stages, and evidence for evaluating the effectiveness of regional climate change health adaptation strategies and measures is scarce. Objective To investigate the level of climate change-related health literacy among residents in Shenzhen, implement targeted health interventions, and assess the intervention effects as well as their influencing factors. Methods From July 2023 to January 2024, 4 communities were randomly selected in Shenzhen, and a total of 896 community residents were enrolled and divided into an intervention group (444 participants) and a control group (452 participants). Baseline and follow-up surveys on climate change-related health literacy were conducted among residents for both groups. During the period between the two surveys, the intervention group received targeted health interventions. Health literacy—comprising 3 dimensions: basic health knowledge and concepts, basic health skills, and healthy lifestyles—was defined as achieving ≥80% of the total score. A differences-in-differences model was adopted to analyze the impact of the intervention, and multiple linear regression was used to explore the factors influencing the intervention effect. Results The baseline survey showed that 240 out of the 896 surveyed residents (26.79%) possessed climate change health literacy. For the 3 dimensions, the number of residents and the proportions with corresponding literacy in descending order were: basic health skills (521, 58.15%), healthy lifestyles (345, 38.50%), and basic health knowledge and concepts (44, 4.91%). After the intervention, the intervention group showed a 3.19% increase in the total health literacy score, a 3.55% increase in basic health knowledge and concepts, and a 4.24% increase in basic health skills (t=2.79, 2.77, and 2.47 respectively) (P<0.05). No significant change was observed in healthy lifestyle scores (t=0.70, P>0.05). Further analysis showed that awareness of the “dual carbon goals” and occupation were significantly associated with the intervention effect on overall health literacy (P<0.05). For basic health knowledge and concepts, occupation, history of chronic diseases, and awareness of the “dual carbon goals” had statistically significant effects on the intervention outcomes (P<0.05). Regarding basic health skills, awareness of the “dual carbon goals” significantly influenced the intervention effect (P<0.001). In terms of healthy lifestyles, gender, educational level, occupation, and awareness of climate change were significantly associated with the intervention effect (P<0.05). Conclusion The climate change-related health literacy among community residents in Shenzhen is in urgent need of improvement. Health interventions can effectively enhance residents' basic health knowledge and concepts, basic health skills, and overall literacy level. In the future, it is necessary to strengthen the popularization of climate change health knowledge based on different population characteristics and further optimize intervention strategies, to comprehensively improve residents' health adaptation capacity to climate change.

Background Gestational weight gain is closely related to maternal and infant health outcomes. Pregnant women are simultaneously exposed to four metals—lithium (Li), vanadium (V), uranium (U), and bismuth (Bi)—through inhalation of fine particulate matter and consumption of contaminated food and water. Existing studies suggest that exposure to these metals may be associated with gestational weight gain. However, no study has yet explored the complex relationships between exposure to mixtures of these four metals and weight gain at different stages of pregnancy. Objective To investigate the associations between mixed exposure to Li, V, U, and Bi in early pregnancy and the average weekly gestational weight gain during both early pregnancy and mid-to-late pregnancy. Methods This prospective study recruited eligible women in early pregnancy from an obstetrics clinic of a tertiary hospital in Jinan, China, between September 2021 and July 2023. Pre-pregnancy weight, current weight (at 11⁺⁰ to 13⁺⁶ weeks of gestation), and spot urine samples (≥5.0 mL) were collected at enrollment. Urinary concentrations of Li, V, Bi, and U were determined using inductively coupled plasma mass spectrometry. Participants were followed up in late pregnancy (≥28 weeks of gestation) to collect information on physical activity via questionnaire; weight measurements at the last antenatal visit (35⁺⁰ to 37⁺⁶ weeks of gestation) were obtained from the hospital information system. After adjusting for covariates, multiple linear regression and generalized additive models were used to assess the associations of individual metals with weekly weight gain in early pregnancy and in mid-to-late pregnancy. Bayesian kernel machine regression (BKMR) and quantile-based g-computation (Qgcomp) were applied to evaluate the joint effects of the metal mixture exposure on weekly weight gain at the two gestational stages. Results A total of 313 pregnant women were included. The geometric means of urinary Li, V, U, and Bi concentrations were 37.07, 0.20, 0.06, and 0.04 μg·L⁻¹, respectively; after creatinine adjustment, the corresponding values were 46.82, 0.25, 0.07, and 0.05 μg·g⁻¹ (Cr). The mean weekly gestational weight gain was (0.19±0.25) kg in early pregnancy and (0.53 ± 0.18) kg in mid-to-late pregnancy. Both multiple linear regression and generalized additive models showed that urinary V concentration was positively associated with average weekly gestational weight gain in early pregnancy, while no significant associations were found for other metals or for gestational weight gain in mid-to-late pregnancy. In the BKMR model with early-pregnancy weight gain as the outcome, V had the strongest association [posterior inclusion probability (PIP)=0.773]. When other metals were fixed at their medians, V showed a positive non-linear association with the outcome. A significant single-metal effect of V and its interaction with Li were observed. Compared with the 50th percentile of the metal mixture, the average weekly weight gain in early pregnancy increased by 0.016 (95%CI: 0.003, 0.029) and 0.018 (95%CI: 0.001, 0.036) at the 60th and 65th percentiles, respectively; conversely, at the 25th percentile, it decreased by 0.026 (95%CI: 0.002, 0.050). Overall, the joint effect of the metal mixture on early- pregnancy weight gain showed an upward trend. In the BKMR model for mid-to-late pregnancy gestational weight gain, all PIPs were<0.5, and no significant single-metal effects, interactions, or joint effects were identified. Qgcomp results confirmed a positive association between the metal mixture and early-pregnancy weight gain (b=0.031, 95%CI: 0.010, 0.051; P<0.01), with V contributing the highest positive weight (0.71). No significant association was found for weight gain in mid-to-late pregnancy (b=0.007, P=0.339). Conclusion Higher levels of co-exposure to the Li, V, Bi, and U metal mixture during early pregnancy may be associated with increased average weekly weight gain in early pregnancy. Among these metals, V exhibits a predominant role and appears to interact with Li. No association is observed between early-pregnancy metal mixture exposure and average weekly gestational weight gain in mid-to-late pregnancy. These findings suggest that monitoring and managing metal exposure during early pregnancy may be crucial for the rational regulation of gestational weight gain.