Objective To investigate the effect of Aedes albopictus mosquito saliva protein (al-MSP) on the infection of human cerebral microvascular endothelial cells (hCMEC/D3) by Dengue virus type 2 (DENV-2). Methods Saliva of adult female Aedes albopictus was collected by sugar-water feeding method, concentrated by ultrafiltration, and then mosquito salivary protein (al-MSP) content in saliva was quantified by BCA protein quantification method. The blood-brain barrier (BBB) model was simulated by inoculating hCMEC/D3 cells in a Transwell. The hCMEC/D3 cells were treated with al-MSP, DENV-2 and al-MSP+DENV-2, Evans blue-serum albumin (EB-BSA) permeation assay was used to assess hCMEC/D3 cell barrier permeability; expression of intracellular intercellular tight junction proteins ZO-1, Occludin, Claudin-5 and DENV2-E mRNA were detected by qRT-PCR; expression of ZO-1, Occludin, Claudin-5, and DENV2-E protein were detected by immunoblotting and immunofluorescence. Results At MOI of 0.1 and 0.5 DENV-2 infected cells for 24 h, EB-BSA concentrations in the lower chamber of BBB model were 32 μg/mL and 68 μg/mL, respectively, indicated that DENV-2 infection significantly increased permeability of the endothelial barrier of hCMEC/D3 cells, whereas treatment with al-MSP alone did not alter the permeability. al-MSP of 0.2, 2 μg/mL increased DENV-2 (MOI=0.1) infected hCMEC/D3 permeability by 38% and 47%, respectively. DENV-2 down-regulated relative mRNA expression of hCMEC/D3 intercellular tight junction proteins ZO-1, Occludin, Claudin-5. ZO-1, Occludin, Claudin-5 mRNA expression in infected cells under the effect of 0.2 μg/mL al-MSP was significantly down-regulated compared to the effect of the virus alone (P<0.001); ZO-1, Occludin (P<0.05) protein expression were all decreased, and Claudin-5 also showed some decreasing trend （P>0.05）; ZO-1 protein immunofluorescence intensity was decreased, but the relative expression of DENV-2 E gene mRNA was increased by 2.4-fold (P<0.001), and the expression of DENV2-E protein was also increased (P<0.001). Conclusions Aedes albopictus salivary proteins promotes DENV-2 disruption of the endothelial barrier in hCMEC/D3 cells, which may be associated with its enhanced DENV-2 replication.
Objective To analyze the epidemiological characteristics of dengue fever (DF) cases reported in Hubei Province from 2015 to 2024, providing a reference for optimizing regional DF prevention and control strategies. Methods Descriptive epidemiology and spatial autocorrelation were used to analyze DF case surveillance data from 2015 to 2024 in Hubei Province, sourced from the China CDC Information System. Results From 2015 to 2024, a total of 557 DF cases were reported in Hubei Province, including 505 imported cases (90.67%). The main sources of importation were Cambodia and Guangdong. The male-to-female ratio was 2.59∶1, with 68.76% of cases occurring in young and middle-aged adults aged 30-59 years, and 44.70% being farmers or migrant workers. The peak incidence period was July to November. Based on the incidence status, DF epidemics in Hubei Province can be divided into four phases: 2015-2018, 2019, 2020-2022, and 2023-2024. Local cases were reported in 2019, 2023, and 2024. Epidemiological characteristics differed significantly across these phases, mainly in terms of age, occupation, case type, time interval from onset to diagnosis, and importation source (all P<0.05). Except for the Shennongjia Forestry District, reported cases have affected 86 counties and districts across 16 prefecture-level cities in Hubei Province, while local cases affected 11 counties in 5 cities, with the scope continuing to expand. Cases in 2019 and 2024 exhibited spatial clustering patterns (global Moran's I>0, indicating positive correlation; P<0.05). Local spatial autocorrelation analysis identified that the border areas among four cities—Wuhan, Ezhou, Huanggang, and Huangshi—as hotspots for both imported and local cases, making them key regions for DF prevention and control in Hubei Province. Conclusion From 2015 to 2024, DF in Hubei Province was predominantly caused by imported cases, with varying epidemiological characteristics across different periods. The disease exhibited spatial clustering, and its geographic scope continued to expand. Enhanced prevention and control measures should be implemented during high-incidence seasons, targeting key areas and populations.
Objective To investigate the initial transmission dynamics at the early stage of a dengue fever outbreak in Hainan, this study aimed to trace the epidemic's onset time, evaluate the effectiveness of implemented prevention and control measures, and explore optimized intervention strategies, thereby providing a theoretical basis for the scientific control of dengue fever. Methods A coupled human-mosquito transmission dynamics model was used to investigate dengue transmission patterns. Model parameters and the onset time of the epidemic were estimated using a combination of numerical simulation and optimization techniques. First, parameters were randomly sampled from a uniform distribution, and for each sample, the differential equations were solved with the fourth-order Runge-Kutta method. The parameter set yielding the minimum Root Mean Square Error （RMSE） was considered optimal. This procedure was repeated, and the median of the resulting optimal parameter sets was taken as the final best estimate. The transmission potential was further assessed through the basic reproduction number R0 Additionally, simulation modeling quantified the effectiveness of three key interventions, including personal protection combined with environmental management u1, larval mosquito control u2, and adult mosquito control u3. Results The estimated onset time of this epidemic was August 15, predating both the first symptom onset and case reporting date. The mosquito-to-human transmission rate was estimated to be 0.85 （95% CI: 0.79-0.88）, and the human-to-mosquito transmission rate was 0.93 （95% CI: 0.87-0.97）. The implemented control measures were estimated to have reduced the total number of infections by 53.6% compared to the no-intervention scenario. During the early epidemic phase without interventions, R0 reached a maximum value of 2.48 at 29.0℃ and a minimum of 1.47 at 23.5 ℃. Following the implementation of control measures on September 20, R0 declined to 0.42 at 23.5 ℃ and 0.98 at 29.0 ℃, respectively. Simulations of the combined three-measure strategy （u1, u2, and u3）, initiated 4 days earlier with respective coefficients of 0.2, 0.15 and 0.06, projected an 49.0% reduction in cumulative new cases and shortened the epidemic's duration by 5 days compared to the no-intervention scenario. Conclusion Prior to the first confirmed case being identified, dengue fever had already been circulating cryptically within the community. Without intervention measures, Hainan's meteorological conditions exacerbated the potential for epidemic transmission. The implemented interventions proved highly effective, significantly reducing case numbers, shortening the duration of the outbreak, and curbing further transmission. Among these measures, the combination of personal protection, environmental management, and adult mosquito control proved to be highly effective. Consequently, future strategies should prioritize vector-targeted interventions, integrated with personal protection and environmental management, to establish a multi-tiered defense framework.
Objective To analyze the epidemiological characteristics of dengue fever cases in Sichuan Province from 2019 to 2024, and to provide a scientific basis for formulating dengue fever prevention and control measures. Methods Data on dengue fever cases in Sichuan Province from 2019 to 2024 were collected from the China Information System for Disease Control and Prevention. Descriptive epidemiological methods were employed for the analysis of epidemic characteristics. Results A total of 641 cases of dengue fever were reported in Sichuan Province from 2019 to 2024, including 611 imported and 30 local cases. Dengue fever cases were reported throughout the year, with peaks in summer and autumn. Local cases occurred exclusively from August to October, with the highest incidence in September (83.33%). Cases were reported in 119 districts/counties across 20 cities/prefectures in the province, with the top five being Chengdu, Luzhou, Deyang, Yibin, and Nanchong. Cities/prefectures with higher reported case numbers were concentrated in Chengdu and the eastern and southern regions of Sichuan. Local cases were reported in Luzhou, Guang'an, Dazhou, and Chengdu. The sex ratio of male to female cases was 1.68:1. Cases were concentrated in the 20 to <60 age group (89.24%), with an age [M (P25, P75)] of 35(28.0, 47.0) years. The top three occupations were farmers/migrant workers/workers (231 cases, 36.04%), housework and unemployment (146 cases, 22.78%), and business services (77 cases, 12.01%). Statistically significant differences were observed in occupational composition across years (χ2=43.157, P<0.01), as well as in sex ratios (χ2=5.056, P<0.05) and occupation (χ2=15.37, P<0.01) between local and imported cases. Overseas imported cases accounted for 64.65% (395/611), mainly from Southeast Asia (93.16%, 368/395), with Cambodia being the most common source. Domestic imported cases accounted for 35.35% (216/611), mainly from Yunnan Province and Guangdong Province. The median interval from onset to diagnosis was 6.4（3.7，9.0） days. A statistically significant difference was found in the onset-to-diagnosis interval across years (χ2=30.669, P<0.01). Conclusions From 2019 to 2024, the number of dengue fever cases in Sichuan Province remained at historically high levels, with sporadic local outbreaks. During peak seasons, it is recommended to strengthen joint prevention and control efforts, strengthen monitoring, standardize epidemic disposal, implement prevention and control measures, and provide targeted health education to high-risk populations.
Objective To investigate the genetic characteristics of the envelope (E) protein gene of dengue virus type 1 (DENV-1) circulating in Hainan Province, China, in 2023, so as to provide a reference for local prevention and control of dengue fever. Methods Serum samples of suspected dengue fever cases in 2023 were collected through Hainan Province's dengue fever monitoring system. RT-PCR detected dengue viral RNA and serotype. RNA-positive samples were subjected to genome sequencing. Homology analysis and amino-acid variation analysis of the E gene were conducted by phylogenetic-tree construction. Results Thirty-eight E protein gene sequences were obtained from 49 DENV1-positive samples. Nucleotide (amino-acid) identity among the 38 sequences was 98.5%-100.0% (98.4%-100.0%). Compared with the Hawaii reference strain (AF425619.1/USA: Hawaii/1945), nucleotide (amino-acid) identity was 93.5%-94.3% (96.0%-97.0%). All 38 sequences belonged to genotype I. Among them, 37 gene sequences clustered into one sub-clade closely related to strains from Myanmar (2019) and Guangzhou, China (2023); the remaining sequence was closely related to strains from Hainan, China (2019), Singapore, Cambodia, and Haikou, Hainan (2021). Relative to the Hawaii strain, 27 of 495 amino-acid residues in the E protein were mutated, but three critical virulence residues [E44(E), E156(T), and E366(N)] and the two glycosylation sites at positions 67 and 153 were conserved. Conclusion The DENV-1 strains circulating in Hainan Province in 2023 belong to Genotype Ⅰ type, and the outbreak may involve two transmission chains. Virulence-associated and glycosylation sites remained unchanged, although multiple mutations were present in the E protein, suggesting that the virus may be under selection pressure during evolution. Therefore, it is recommended to continuously strengthen pathogen surveillance of dengue fever and implement more effective prevention and control measures.
Objective To analyze the epidemiological characteristics of imported dengue fever in Fujian Province, aiming to provide a reference for accurate and scientific prevention and control of dengue fever. Methods Surveillance data on imported dengue fever cases reported in Fujian Province from 2005 to 2023 were collected through the Chinese Center for Disease Control and Prevention Information System. Descriptive epidemiological methods were employed to analyze the distribution characteristics of imported dengue fever. Heat maps, Sankey diagrams, and regression curves were generated using R software. Results From 2005 to 2023, a total of 1 186 imported dengue fever cases were reported in Fujian Province from 2005 to 2023, exhibiting an overall upward trend (except for 2020-2022). The trend in the number of affected counties (cities, districts) was consistent with the trend in the number of reported cases. The distribution of cases displayed a significant seasonal pattern, with peaks occurring annually from June to October. Imported cases were reported in 62 counties (cities, districts) across 9 prefecture-level cities and the Pingtan Comprehensive Experimental Zone, with Quanzhou (423 cases, 35.67%), Fuzhou (316 cases, 26.64%), and Xiamen (221 cases, 18.63%) accounting for 80.94% (960/1 186) of the total imported cases. Imported dengue fever cases in Fujian Province originated from 31 countries and regions worldwide, with the Western Pacific Region being the most common source (933/1 186, 78.67%). The main countries of origin were Cambodia (550 cases, 46.37%) and the Philippines (263 cases, 22.18%). Among imported cases, the gender ratio (male: female) was 3.18:1 (902/284); the majority of patients (91.23%, 1 082/1 186) were aged 21-60 years; the top three occupations among cases were homemakers/unemployed, farmers, and commercial services, collectively accounting for 63.83% (757/1 186) of all imported cases. The median from symptom onset to diagnosis was 5.3 days, showing an overall downward trend. A linear relationship was found between the number of imported cases and the number of inbound international travelers, described by the equation y=0.021 7x+0.374 3 (R2=77.78%, F=59.51, P<0.001). Conclusion The epidemic of imported dengue fever in Fujian Province shows a sustained upward trend, with distinct temporal, spatial, and demographic clustering of cases. Therefore, it is recommended to enhance the prevention and control of dengue fever among key inbound populations, tailored to specific temporal and geographical risk factors.
Objective To compare the characteristics of dengue fever cluster epidemics in Hainan Province in 2023 and 2024, we provide evidence for comprehensive understanding of dengue fever epidemic patterns in Hainan Province and exploring more effective control and prevention measures. Methods Descriptive epidemiological methods were used to analyze the temporal, spatial, and demographic distribution, serological testing, case diagnosis, and clinical manifestations of dengue fever cluster epidemics in Hainan Province from 2023 to 2024. Excel 2021 and R 4.3.0 software were used for data processing and analysis, and ArcGIS 10.8 software was employed for visualization of geographical distribution. Results In 2023, 8 dengue fever cluster epidemics were reported, occurring from August to November, affecting 5 cities and counties, with 318 associated cases accounting for 87.60%(318/363) of the total reported cases that year. The main epidemic sites were communities and townships/rural areas, with dengue virus type 2 being the predominant strain (255, 80.70%). The M (P25, P75) interval from onset to diagnosis was 1(0.75, 2) days. In 2024, 9 dengue fever cluster epidemics were reported, occurring in July and October-November, affecting 4 cities and counties, with 62 associated cases accounting for 38.27% of the total reported cases that year. Communities/villages in cities were the primary epidemic settings, with dengue virus type 1 being the predominant strain (42, 67.74%). The M (P25, P75) interval from onset to diagnosis was 1(1, 3) days. No severe cases or deaths occurred among dengue fever cluster cases in both years. Statistically significant differences were observed in case source locations, occupation, virus serotype, and case detection methods (P<0.05), while no significant differences were found in gender, age, and interval from onset to diagnosis (P>0.05). Conclusion The scale of clustered epidemics in 2024 was significantly reduced compared to 2023, with cases detected timely. Future efforts should focus on continuously optimizing dengue fever control and prevention strategies, enhancing epidemic response capacity, and establishing more precise surveillance and early warning systems, with strengthened monitoring in coastal areas, tourist hotspots, and regions with frequent population movement during summer and autumn, expanding the scope of at-risk population screening, and improving surveillance sensitivity.
Objective To monitor the density and seasonal fluctuation of dengue vector Aedes in Fujian Province from 2020 to 2024, and we provide scientific evidence for the prevention and control of dengue fever. Methods From March to November each year from 2020 to 2024, the double-layered tent method was used to monitor the density of adult Aedes, and Breteau index method was applied to monitor larval density. Statistical analysis of monitoring data were performed using Kruskal-Wallis H rank sum test, chi-square test, multivariate analysis of variance, and Spearman rank correlation analysis with SPSS 19.0 software. Results All Aedes mosquitoes captured were Aedes albopictus in Fujian Province from 2020 to 2024, none of Aedes aegypti were found. The average tent trapping index was 4.35 mosquitoes/(tent·hour); the average Breteau index (BI) was 6.96; the average container index (CI) was 14.12. Both the average tent trapping index and BI peaked in June. There were no significant differences between adult and larval densities across different years (P>0.05), with roughly the same trends annually. The highest average adult Aedes albopictus density [5.77 mosquitoes/(tent·hour)] was found in parks or bamboo forests, while the larval density was highest in residential areas and lowest in hospitals. Larva-positive water bodies were predominantly idle containers (bowls, bottles, jars and cans), accounting for 46.10%. There were at least 8 months each year when the densities of adult Aedes exceeded the dengue prevention threshold; and there were at least 6 months when the BI value exceeded the threshold. A strong positive correlation existed between tent trapping index and BI, with the regression equation: Y (tent trapping index)=0.748X(BI)-0.980. Conclusion The dengue vector Aedes are Aedes albopictus exclusively in Fujian Province, the activity of Aedes albopictus has been monitored from March to November; June to September represents the peak activity period, when it is necessary to pay more attention to the surveillance vector Aedes, controlling its density by eliminating larval-breeding sites, therefore to strengthen the ability of prevention and control of dengue fever.
Objective To compare the epidemiological characteristics of local dengue fever outbreaks from 2023 to 2024, in order to provide a basis for control and prevention of dengue fever epidemic. Methods Information on dengue fever cases was exported from Chinese Disease Control and Prevention Information System, and the epidemiological characteristics of the local dengue fever outbreaks in 2023 and 2024 were analyzed by descriptive analysis methods in combination with epidemiological investigation data. Results The local outbreaks were caused by dengue virus type 1 both in 2023 and 2024. The local dengue outbreak lasted for 61 days in 2023, with Haitang district (97.87%) as the main infected area; and the local outbreak lasted for 35 days in 2024, with Jiyang district (96.55%) as the main infected area. Cases were predominantly males aged 20-60 years, accounting for 61.70% in 2023 and 82.76% in 2024. Occupational distribution was dominated by commercial service workers in 2023, accounting for 65.96%, and farmers or migrant laborers in 2024, accounting for 37.93%. The proportion of patients detected through active screening was 41.38% in 2024, higher than 19.15% in 2023, the difference was statistically significant（χ2=4.432，P=0.035）. Dengue virus NS1 test reagents were available at the first healthcare facility for cases in 37.50% in 2023 and 75.00% in 2024. Analysis of the number of visits for confirmed dengue showed a mean number of 1.77 visits in 2023 and 1.21 visits in 2024. The proportion of visits on the day of onset of illness was 31.11% in 2023 and 47.37% in 2024. The proportion of patients with a confirmed dengue diagnosis on the first visit was 64.44% in 2023 and 78.95% in 2024. The percentage of dengue fever diagnosed on the day of onset was 12.77% in 2023 and 27.59% in 2024. The percentage of patients admitted to hospital within 5 days of onset was 95.65% in 2023 and 100.00% in 2024. Conclusion The emergency response to the local epidemic was faster in 2024 than in 2023, and duration of the epidemic was significantly shorter. Training of medical personnel should be strengthened to improve their awareness and level of dengue fever diagnosis and treatment. The construction of monitoring system should be improved and strengthened so that outbreaks can be detected and disposed of in a timely manner in order to reduce the risk of dengue fever outbreaks and epidemics.
Objective To evaluate objectively and analyze the spatiotemporal distribution and ecological factors affecting Aedes albopictus, and explore the application of geographic information systems (GIS) and MaxEnt model in the monitoring of Aedes albopictus. Methods The large-scale comprehensive residential community was selected as the research object in Songjiang New City, and four monitoring results based on mosq-ovitraps were recorded from August to September 2024. The spatial evolution characteristics of Aedes albopictus was measured by global spatial autocorrelation, hot spot analysis, standard deviation ellipse and center of gravity migration trajectory. The maximum entropy model was used to characterize mosquito habitat preference, the AUC value was used to evaluate accuracy of the model prediction, while contribution rate and permutation importance were used to identify the key variables affecting mosquito distribution. Results A total of 432 mosq-ovitraps were placed throughout the monitoring period, of which 389 were recovered and 90 were positive, with an average mosq-ovitrap index of 23.14. The global Moran's I index of the four monitorings were close to 0 and the P value was greater than 0.05, indicating a random spatial distribution of Aedes albopictus. The results of the hotspot analysis indicated that there were high-value clustering areas with a 99% confidence level in all four monitorings. During the monitoring period, there were no statistically significant differences observed in low-value spatial clustering. The first two monitoring results showed that the elliptical "centripetal force" was greater, and the degree of data dispersion was smaller than that of the last two monitoring results. The center of gravity showed the trend of "Z" to the south, with a total displacement of 122.23 m. The intersection of ellipses indicated that related positive mosq-ovitraps with temporal and spatial accumulation should be prioritized for control. The average AUC value of MaxEnt model was 0.716±0.054. Among the environmental variables, the top five in importance were NDVI, land surface temperature, precipitation in the warmest quarter, commercial POI and residential POI. Conclusion Geographic information systems can help identify areas with abnormally high mosquito density, and NDVI has the most significant impact on the spatial distribution of mosquitoes.
Objective To understand epidemiological characteristics of dengue fever in Ruili City from 2013 to 2024, to provide a reference basis for scientific control and prevention of dengue fever. Methods Information on reported dengue fever cases in Ruili from 2013 to 2024 was collected through the China Disease Control and Prevention Information System (CDCIS) and epidemiological surveys, and descriptive epidemiological methods were used to analyze the data on dengue fever cases. Brett index (BI) was used to analyze the vector Aedes larval density monitoring data, and association between the number of cases and Brett index was analyzed using Spearman correlation. Results A total of 9 122 dengue fever cases were reported in Ruili City from 2013 to 2024, including 7 128 local cases (78.14%), 18 imported cases (0.20%) within the country, and 1 976 imported cases (21.66%) from abroad, with imported cases from abroad mainly from Myanmar (99.29%, 1 962/1 976). Both local and imported cases were concentrated in August-November, and there was a significant correlation between temporal distribution (r=0.96, P<0.01). There was no statistically significant difference in gender between imported and local cases. The minimum age of the cases was 1-day-old and the maximum age was 93-years-old, and the median age of onset of the imported cases was younger than that of the local cases. The top three occupations with the highest incidence of cases were commercial services, domestic work, and students. Cases were reported in all six townships in Ruili City, with Mengmao Town (Ruili urban area) being the most predominant. Imported cases had a longer interval between onset and diagnosis than local cases. There was a significant positive correlation between the number of dengue cases and Brett index in Ruili City (r=0.82, P=0.01). Conclusion Ruili City has been experiencing local epidemics of dengue for 12 consecutive years from 2013 to 2024. At the same time, Ruili City is adjacent to Myanmar, with many border crossings, developed transportation and logistics, and frequent movement of people, the imported cases reported in Ruili City are mainly imported from Myanmar, and the situation of dengue fever control and prevention has been more severe. Strengthening the monitoring and management of cross-border transmission of dengue fever along the China-Myanmar border as well as regularization of mosquito control and prevention are the key measures to control dengue fever in the region.
Dengue fever imposes a growing global burden of disease, characterized by considerable spatiotemporal heterogeneity in its transmission dynamics. Epidemiological surveillance and early warning models serve as crucial tools for evaluating the risk of dengue outbreaks and transmission risks, thereby guiding subsequent targeted prevention and control efforts. This review synthesizes published studies on dengue surveillance and early warning models globally, examining their temporal and spatial distribution. It summarizes the predictive factors and modeling approaches employed in these models and evaluates the quality of the research. Meteorological and environmental variables, along with historical dengue surveillance data, are the most frequently utilized predictors. Modeling methodologies have evolved substantially, shifting from traditional time series analyses and infectious disease dynamic models to advanced machine learning techniques, with each method offering distinct advantages in various application scenarios. Future research should adhere to the reporting guidelines recommended by the recommended reporting items for epidemic forecasting and prediction research (EPIFORGE 2020) framework to improve study quality and practical value.
Objective To analyze the epidemiological characteristics of dengue fever outbreaks that occurred at construction sites in Sanya City and Lingshui Li Autonomous County, Hainan Province, in 2024, and to provide evidence for targeted prevention and control. Methods Descriptive epidemiological methods were used to analyze the temporal, spatial, and demographic distribution characteristics of dengue fever cases at construction sites. Whole-genome sequences of the isolated dengue viruses were obtained, followed by homology alignment and phylogenetic analysis. Results In 2024, a total of 27 confirmed dengue fever cases were reported from construction sites in Sanya City and Lingshui Li Autonomous County in Hainan Province, comprising 22 indigenous and 5 imported cases, with two outbreaks identified. The onset time was mainly from October 16 to November 2, with 23 cases accounting for 85.19%. Twelve cases were reported in Sanya City and fifteen in Lingshui Li Autonomous County. Twenty-four cases were male and three female; the median age was 47 years, and 16 cases (59.26 %) were in the 40-<60 age group. Construction workers constituted the majority of cases (25 cases, 92.59%), and most were detected through patients actively seeking medical attention (17 cases, 62.96%). At the first round of monitoring, the Breteau Index in all nine core areas of construction sites exceeded 5. Phylogenetic analysis showed that 20 dengue virus sequences from Sanya City and Lingshui Li Autonomous County in 2024 (including 16 from this study) belong to the same major evolutionary branch, closely related to KX621253 Guangdong China 2016Ⅰ and OM281596 Maldives 2019Ⅰ. Conclusion Construction sites were the key locations for dengue prevention and control. It is crucial to enhance vector surveillance, especially in high-risk seasons, to maintain mosquito vector density at safe levels and reduce the risk of outbreaks. During the epidemic period, rapid elimination of adult mosquitoes, cleanup of breeding sites, and strengthened health monitoring of construction workers, especially migrant workers, are essential to prevent cross-site transmission.
Objective To analyse epidemiological characteristics of a local outbreak of dengue fever in a flower and bird market in Changzhou City, Jiangsu Province in October 2023, evaluate effectiveness of control measures, and provide a reference for control and prevention of dengue fever in the future. Methods Collect all the case data of a dengue fever outbreak at a flower and bird market in Changzhou City, Jiangsu Province in October 2023, descriptive analysis methods were used to analyze epidemiological characteristics of the outbreak. The Breteau index method and double-layer trap method were employed to monitor mosquito density and evaluate effectiveness of control measures. Results The outbreak lasted for 15 days. A total of 4 confirmed cases and 8 latent cases were reported, all of them were local cases. There were workplace-related clusters and no positive cases among the co-residents. The 4 confirmed cases were all engaged in flower retail industry, and were mild. The disease duration ranged from 5 to 18 days. The maximum time interval from onset to diagnosis of the confirmed cases was 14 d, and serotypes of all dengue virus were DENV-1. The whole genome sequence of 3 virus strains was obtained, and the homology among which was 99.83%. After implementing control measures such as case search, isolation and treatment, mosquito control, cleaning of mosquito breeding sites, and health education within the core area, Breteau index decreased from the initial 18.62 to below 5, and the bite index was controlled at≤2 mosquitoes per person-hour. Conclusions This was the first local outbreak of dengue fever in Jiangsu Province, which might be caused by the transportation of mosquitoes infected with dengue virus or their larvae to flower and bird market through green plants. The outbreak had been effectively contained after mosquito control and prevention measures. Improving the awareness and sensitivity of healthcare personnels in non-endemic areas plays a key role in early diagnosis of cases and early detection of the outbreak.
Objective To understand the molecular characteristics of Coxsackievirus A16 (CVA16) in the border area of Xishuangbanna, Yunnan Province, and the evolutionary relationship between the epidemic strains at home and abroad, so as to provide a scientific basis for control and prevention, and its molecular traceability of CVA16 in Xishuangbanna. Methods In December 2024, throat swabs from children diagnosed clinically as suspected hand-foot-mouth disease were collected in the First People's Hospital of Jinghong City, Xishuangbanna Prefecture. Viral nucleic acids were extracted, Nested RT-PCR was used to amplify VP1 gene sequence of the virus. Sequence analysis was conducted using bioinformatics software such as MEGA 7.0. Results A total of 36 throat swab samples of suspected HFMD children were collected; 3 samples were positive for CVA16-VP1 (sample number: 3/JH-YN/2025, 5/JH-YN/2025, 6/JH YN/2025VP1), and the detection rate was CVA16 (8.33%). The results of sequence analysis showed that the three sequences obtained in this study were located in the same evolutionary branch with the epidemic B1a gene subtype CVA16 in Jiangxi Province of China in 2022 and 2023, with nucleotide homology of more than 89% and amino acid homology of more than 92%; while other subtypes of CVA16 were located in different evolutionary branches, with nucleotide homology less than 89% and amino acid homology less than 90%, suggesting that CVA16 B1a was the main subtype of HFMD virus in Jinghong in December; Amino acid analysis showed that the three positive strains in Jinghong city were in line with the current epidemic pattern of the novel B1a gene VP1-164K/251I, and there were 4 mutations in 16 mutation-prone sites. The 145th amino acids were not mutated, which was consistent with E145V, that is, the virulence of local epidemic strains might be enhanced. There were site-specific mutations of individual strains in 252, 261 positions, and 266 site-specific mutations in all three strains, which might be related to adaptive transmission or specific mutations produced by local strains to enhance epidemic of the virus in the population. Conclusions In December 2024, there was a CVA16-B1a subtype epidemic in Jinghong, Xishuangbanna, which was closely related to the epidemic strains in other areas of Yunnan and Jiangxi in recent years, providing a scientific basis and guiding significance for the diagnosis and prevention of HFMD in this area.
Objective To investigate the relationship of the platelet-lymphocyte ratio (PLR), the red blood cell distribution width-to-albumin ratio (RAR), and the systemic immune-inflammation index (SII) with the risk of venous thromboembolism (VTE) in patients with pulmonary tuberculosis (PTB), and to provide early warning clues for clinical identification of VTE risk in PTB patients. Methods Between January 2022 and September 2024, 323 pulmonary tuberculosis (PTB) inpatients at the Third People's Hospital of Kunming were divided, according to the Padua score, into a high-risk group (116 cases) and a low-risk group (207 cases). First, the differences in baseline information, such as gender, ethnicity, hypertension, and diabetes, between the two groups of patients were compared using the chi-square (χ²) test. Subsequently, the differences in levels of platelet count (PLT), neutrophil count (NEU), lymphocyte count (LYM), red blood cell distribution width (RDW), albumin (ALB), SII, RAR, and PLR between the two groups were compared using the Mann-Whitney U test. Indicators showing significant differences were entered into multivariate logistic regression to identify independent risk factors. Receiver operating characteristic (ROC) curves were constructed separately to evaluate the predictive value of each indicator, and the area under the ROC curve (AUCs) was compared with the DeLong test. Results The NEU, RDW, PLR, SII and RAR levels in the high-risk group were significantly higher than those in the low-risk group, while the LYM and ALB levels were significantly lower (P<0.05). Multivariate logistic regression analysis showed that elevated RAR and PLR are independent risk factors for VTE in patients with tuberculosis, while elevated SII levels have only general risk predictive value. ROC curve analysis further suggests that the combined RAR and PLR detection has a high predictive effect on high-risk groups in VTE, with an AUC of 0.823 (95%CI: 0.778~0.868). Conclusion RAR and PLR can be used as independent predictors of VTE in patients with tuberculosis, and the combined detection of the two has good predictive value. Monitoring these indicators can help identify patients at high risk of VTE in the early stage and provide a reference for clinical intervention.
Objective To investigate the independent impact of hepatic steatosis (HS) on hepatitis B surface antigen (HBsAg) seroclearance among chronic hepatitis B virus (HBV) infected participants and to evaluate its interaction with antiviral therapy, thereby providing a basis for elucidating the underlying mechanism by which HS influences chronic HBV infection and guiding the optimization of individualized treatment strategies. Methods From the prospective Wuwei (Gansu Province) Chronic HBV Cohort (2018-2024), 2 251 regularly followed participants were included. HS was defined as a controlled attenuation parameter (CAP) ≥248 dB/m measured by transient elastography (FibroScan). The association between HS and HBsAg seroclearance was evaluated using multivariable Cox proportional hazards models, and stratified analyses were performed to assess the moderating effect of antiviral therapy. The models were adjusted for potential confounders such as age, sex, viral load, hepatitis B e antigen (HBeAg) status, and treatment status. Firth's correction was applied to correct small-sample bias. Results Among 2 251 HBV-infected participants, 762 cases (33.8%) were complicated by HS. Compared with non-HS participants, those with HS were older, had a significantly higher proportion of males, urban employees, smoking rate, alcohol consumption rate, and tea consumption rate, while the rate of nucleos(t)ide analogue (NA) treatment, prevalence of liver cirrhosis, proportion of family history of hepatitis B, and HBeAg positivity rate were significantly lower (all P<0.05). Biochemical profiling showed elevated ALT, ALB, and GGT levels in HS patients, alongside reduced TBIL and DBIL levels (all P<0.05). During a median follow-up of 2.9 years, the HS group demonstrated significantly higher HBsAg seroclearance rates compared to the non-HS group (adjusted HR=1.50, 95%CI: 1.06-2.12, P=0.021). Stratified analysis revealed that HS markedly increased the likelihood of HBsAg seroclearance in patients who never received antiviral therapy (HR=1.64, 95%CI: 1.02-2.66, P=0.044), whereas no significant association was observed in antiviral-treated HBV-infected participants (HR=1.18, P=0.530). Conclusion Hepatic steatosis may augment spontaneous HBsAg seroclearance in untreated chronic HBV patients through metabolic regulatory pathways. These findings suggest that metabolic interventions could serve as adjuncts to antiviral therapy and promote a transition from a single-target antiviral model to a multi-target, synergistic management strategy for chronic HBV infection.
Objective To analyze the epidemiological characteristics of tuberculosis and the delay in consultation among children aged 0-14 years in Guizhou Province from 2016 to 2022, and to provide a scientific basis for the formulation of tuberculosis prevention and treatment measures. Methods Through subsystem "Tuberculosis Management Information System" of "China Disease Control and Prevention Information System", the case data of 0-14-year-old children with pulmonary tuberculosis registered and managed in Guizhou Province from 2016 to 2022 were exported, and the descriptive epidemiology method was used to analyze the epidemic characteristics and delayed consultation of this population. Results A total of 3 688 cases of tuberculosis in children aged 0-14 years were registered and managed in Guizhou Province from 2016 to 2022, accounting for 1.39% (3 688/265 613) of tuberculosis cases in the whole population during the same period, showing an increasing trend (χ2trend=158.963, P<0.05), with an average annual reported incidence rate of 5.94/100 000. There was an increasing trend in the reported incidence rate in each year (χ2trend=34.593, P<0.05). Among them, there were 1 764 boys (47.83%) and 1 924 girls (52.17%), with a male-to-female ratio of 0.92∶1; the incidence rate in each year was the highest in the group of 12-14 years old. The main modes of patients discovery were referral (37.28%) and consultation due to symptoms (29.18%); the total delay in patient consultation was 50.68% (1 869/3 688), with a decreasing trend (χ2trend=11.238, P<0.05); cases were reported in every quarter of the year, with the highest number of cases reported in the third quarter; the region with the highest number of patients was Bijie, accounting for 38.18% (1 408/3 688); the results of multifactorial logistic regression analysis showed that patients with retreatment (OR=2.756, 95% CI:1.151-6.600) and pathogen-positive(OR=1.312, 95% CI:1.123-1.533) had a higher risk of delayed consultation, and patients with active screening(OR=0.550, 95% CI:0.346-0.873) and detected by health checkup (OR=0.578,95%CI:0.459-0.729) had a lower risk of delayed consultation. Conclusion There is a need to further strengthen proactive screening for childhood tuberculosis and health checkups for new students enrolled in school for early detection and treatment of pediatric tuberculosis patients.
Objective To address the insufficient control efficacy against cockroaches in food service establishments caused by frequent chemical control of pesticide resistance, this study investigated the short-term rapid elimination and long-term sustained suppression effects of different combined insecticide strategies on cockroach populations, aiming to provide a scientific basis for optimizing integrated pest management (IPM) strategies. Methods Shanghai will be selected in August and September 2024 five eligible food service establishments were selected and divided into five experimental groups: Group 1 (Fipronil gel bait), Group 2 (Hydramethylnon gel bait), Group 3 (α-Cypermethrin spray + Fipronil spray), Group 4 (α-Cypermethrin spray + Fipronil gel bait), and Group 5 (Fipronil spray + Hydramethylnon gel bait). Gel baits were applied to hidden crevices according to product instructions, while spray insecticides were administered based on repellent or toxicant properties. Cockroach density was monitored using sticky traps before and after treatment, with density reduction rates calculated on days 1, 3, 7, 15, 30, and 45. Intergroup differences were analyzed using repeated-measures Friedman rank-sum tests. Results Density reduction rates of single gel bait groups (Groups 1 and 2) achieved 74.50% and 74.36% on day 7, reaching 88.56% and 89.74% on day 45, respectively. Density reduction rates of the dual-spray group (Group 3) showed 86.13% on day 7 and 98.02% on day 45. Combined groups (Groups 4 and 5) demonstrated reductions of 70.00% and 98.04% on day 7, and 88.46% and 99.51% on day 45, respectively. All five strategies achieved satisfactory control efficacy of cockroach(density reduction rates>80%). Group 5 (Fipronil spray + Hydramethylnon gel bait) outperformed the other four groups,with statistically significant differences(P<0.05). Conclusion Combined insecticide strategies, particularly spray-gel bait combinations, rapidly reduce cockroach density and sustain long-term suppression. The Fipronil spray and Hydramethylnon gel bait combination (Group 5) exhibited optimal comprehensive efficacy, and is recommended as a high-efficiency cockroach management protocol for food service establishments. Practical applications should flexibly select strategies based on infestation severity and environmental characteristics.
Objective To understand the molecular transmission characteristics of newly reported HIV-1 infected individuals in Hebei Province from 2022 to 2023, analyze the transmission network, identify high-risk cases with a degree value ≥ 4, as well as the transmission of drug-resistant strains, so as to provide a reference for precise HIV intervention. Methods Plasma samples of newly reported HIV-1 infected individuals in Hebei Province from 2022 to 2023 were collected. The HIV-1 pol region gene was amplified through reverse transcription and nested polymerase chain reaction and drug resistance mutation analysis was used by the Stanford HIV Drug Resistance Database. The molecular transmission network was constructed using the TN93 model to analyze the high-risk transmission clusters. Logistic regression was used to analyze potential risk factors of the molecular transmission network (with the number of nodes ≥2). Arcgis analysis was carried out to display cross-city transmission intensity of HIV-1 infected individuals. Results Among the 555 HIV-1 infected individuals, the majority were male, Han ethnicity, and the transmission route was through homosexual. A total of 12 genotypes were identified. Among them, the main HIV-1 strains were CRF01_AE (46.7%) and CRF07_BC (38.7%). The drug resistance rate was 8.3%, and the most common drug resistance mutations were K103N (1.3%), followed by E138G (0.7%). Under the 1.5% gene threshold, a total of 182 sequences entered the molecular transmission network, forming 61 transmission clusters, with a network entry rate of 32.8%(182/555). The cases were mainly male (93.4%) and the transmission route was through homosexual (81.9%), It involved 11 cities and showed cross-regional transmission characteristics, and there were 13 cases with high transmission risk (degree ≥ 4 ). A total of 18 sequences carrying drug-resistant mutation sites were identified in 9 transmission clusters. Among them, the E138G drug-resistant mutation site was found to be spreading in a CRF07_BC transmission cluster (the number of nodes = 5). Multivariate logistic regression showed that clustering rate of student was higher than that of farmers (aOR=3.20, 95%CI:1.46-7.04); CRF01_AE (aOR=2.83, 95%CI:1.26-6.35) and CRF07_BC (aOR=3.60, 95%CI:1.60-8.12) had a higher clustering rate compared with the novel recombinant strains. In terms of regional transmission, the cross-city connections in the central and southern cities of Hebei Province were more frequent compared with northeastern cities. Conclusion We have identified high-risk populations and drug-resistant transmission clusters through the molecular transmission network. Strengthening precise intervention measures such as antiviral treatment and follow-up for high-risk populations is of great significance for controlling transmission of HIV and drug-resistant strains in Hebei Province.
Objective To analyze etiological characteristics, antimicrobial resistance genotypes, and genetic evolutionary patterns of Salmonella in Hainan Province in 2021, to provide a scientific basis for formulating prevention strategies and public health management of Salmonella infections. Methods Whole genome sequencing was performed on 208 Salmonella isolates (134 human-derived, 70 food-derived, and 4 of unknown origin) from Hainan Province, 2021. Sequences were assembled using SPAdes, serotyped by the SISTR database, and analyzed for resistance genes using ResFinder. Sequence types (STs) were determined by PubMLST. Core genome SNP phylogenetic trees were constructed with Parsnp, and epidemiological data were integrated to identify clustering events. Results In 2021, 31 serotypes were detected in 208 strains of Salmonella in Hainan Province. The main dominant serotypes were Salmonella enterica serovar 1,4,[5],12:i:- (monophasic S. Typhimurium, 28.37%), followed by S. Enteritidis (12.02%), and S. Weltevreden (12.02%). Human-derived strains were dominated by monophasic S. Typhimurium (35.82%), S. Enteritidis (14.18%), and S. Weltevreden (11.19%), while food-derived strains primarily included S. Weltevreden (14.29%), S. Derby (12.86%), and monophasic S. Typhimurium (10.00%). A total of 37 STs were identified, with predominant ST34 being 21.63% (all were monophasic S. Typhimurium), ST11 12.02% (all were S. Enteritidis), and ST365 12.02% (all were S. Weltevreden). Eleven isolates carried 3 to 13 multidrug resistance genes, primarily in human-derived monophasic S. Typhimurium and S. Typhimurium. Genomic analysis revealed 7 clusters: 2 confirmed foodborne outbreaks (S. Weltevreden and S. Enteritidis), 4 potential outbreaks (3 monophasic S. Typhimurium, and 1 S. Weltevreden), and 1 indicating widespread contamination of pork products by S. Newport. Conclusion The epidemiology of Salmonella in Hainan is dominated by monophasic S. Typhimurium, S. Enteritidis, and S. Weltevreden. Despite low prevalence of multidrug resistance genes, high-risk clonal transmission persists, pork may be an important source of outbreaks caused by Salmonella in Hainan. Genomic surveillance effectively identifies cross-regional outbreaks and contamination sources. We recommend enhanced hygiene management of high-risk foods, antimicrobial resistance monitoring, and prioritized prevention of S. Weltevreden.
Objective To retrospectively analyze the epidemiological characteristics and spatiotemporal clustering of hemorrhagic fever with renal syndrome (HFRS) in Jining City from 2014 to 2023, aiming to provide a data-driven basis for the precise prevention and control of HFRS. Methods HFRS case data for Jining City were retrieved from the China Disease Control and Prevention Information System. Descriptive statistical analysis, spatial autocorrelation analysis, and spatiotemporal scanning analysis were conducted. Results From 2014 to 2023, a total of 650 HFRS cases were reported in Jining, with an average annual incidence rate of 0.79 per 100 000 population. Cases exhibited significant seasonality, with peaks primarily in spring and winter. The male-to-female ratio was 2.08:1, and farmers accounted for the majority (86.92%), with most cases (62.46%) occurring in individuals aged 30 to <60 years. High-incidence areas were mainly Jinxiang County, Jiaxiang County, Sishui County, Zoucheng City, and Rencheng District, which together represented 85.85% of the cases. Global spatial autocorrelation analysis indicated clustering of HFRS cases across towns (subdistricts) from 2014 to 2019, with high-value clustering from 2016 to 2018. Local spatial autocorrelation analysis identified high-high clustering areas annually from 2014 to 2022; these were primarily in the southwestern region, concentrated in Jinxiang County and Jiaxiang County from 2014 to 2018, while from 2019 to 2022, the number of such clusters decreased and became more scattered. Spatiotemporal scan analysis identified two clusters: the TypeⅠclustering group was located in Jinxiang County, Yutai County, and Jiaxiang County, spanning from January 2014 to May 2018; the Type Ⅱ clustering group was located in Sishui County, spanning from January 2014 to December 2018. Conclusion From 2014 to 2023, the incidence of HFRS in Jining City showed an overall downward trend, with peaks mainly in spring/summer and winter, exhibiting clear seasonality and spatiotemporal clustering. The southwestern and eastern regions were high-risk areas, and farmers were the most affected population.
Helsmoortel-Van der Aa syndrome (HVDAS) is a rare neurodevelopmental disorder primarily caused by mutations in the active-dependent neuroprotective protein (ADNP) gene, representing one of the most common monogenic causes of autism spectrum disorder (ASD). This retrospective analysis describes a 3-year-and-10-month-old boy with HVDAS who presented at Haikou Maternal and Child Health Hospital in 2024 with autism spectrum disorder, global developmental delay, distinctive facial features, short stature, and hydrocephalus. Genetic testing revealed a heterozygous mutation in the ADNP gene [NM_001282531.3(ADNP): c.2189 (exon 6) delG [p.(Arg730Glnfs3)]], with no family history of this mutation among his parents or sister. Summarizing the clinical data alongside a literature review, the ADNP gene plays a crucial role in chromatin remodeling and neurodevelopmental disorders, with mutations capable of affecting multiple systems. This case exemplifies the typical clinical manifestations of HVDAS while broadening the phenotypic spectrum of hydrocephalus, providing valuable insights for genetic counseling and early clinical identification of such genetic variants.
