1.National bloodstream infection bacterial resistance surveillance report 2023: Gram-positive bacteria
Chaoqun YING ; Jinru JI ; Zhiying LIU ; Qing YANG ; Haishen KONG ; Jiangqin SONG ; Hui DING ; Yanyan LI ; Yuanyuan DAI ; Haifeng MAO ; Pengpeng TIAN ; Lu WANG ; Yongyun LIU ; Yizheng ZHOU ; Jiliang WANG ; Yan JIN ; Donghong HUANG ; Hongyun XU ; Peng ZHANG ; Xinhua QIANG ; Hong HE ; Lin ZHENG ; Junmin CAO ; Zhou LIU ; Ying HUANG ; Yan GENG ; Haiquan KANG ; Dan LIU ; Guolin LIAO ; Lixia ZHANG ; Fenghong CHEN ; Yanhong LI ; Baohua ZHANG ; Haixin DONG ; Xiaoyan LI ; Donghua LIU ; Qiuying ZHANG ; Xuefei HU ; Liang GUO ; Sijin MAN ; Dijing SONG ; Rong XU ; Youdong YIN ; Kunpeng LIANG ; Aiyun LI ; Zhuo LI ; Hongxia HU ; Guoping LU ; Jinhua LIANG ; Qiang LIU ; Yinqiao DONG ; Jilu SHEN ; Shuyan HU ; Liang LUAN ; Jian LI ; Ling MENG ; Dengyan QIAO ; Xiusan XIA ; Bo QUAN ; Dahong WANG ; Chunhua HAN ; Xiaoping YAN ; Fei LI ; Shifu WANG ; Ping SHEN ; Yunbo CHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2025;18(2):118-132
Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System(BRICS)during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute(CLSI). Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus( n=1 544,35.2%),coagulase-negative Staphylococci( n=1 441,32.9%), Enterococcus faecium( n=574,13.1%), Enterococcus faecalis( n=385,8.8%),and α-hemolytic Streptococci( n=187,4.3%). The prevalence of methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-resistant coagulase-negative Staphylococci(MRCNS)was 26.2%(405/1 544)and 69.8%(1 006/1 441),respectively. Notably,all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility(>97.0%)to cephalobiol,rifampicin,trimethoprim-sulfamethoxazole,linezolid,minocycline,tigecycline,and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium(resistance to vancomycin and teicoplanin:both 1.7%)compared to Enterococcus faecalis(both 0.3%). The detection rates of MRSA and MRCNS exhibited significant regional variations across the country( χ2=17.674 and 148.650,respectively,both P<0.001). No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA( χ2=14.111, P<0.001)and MRCNS( χ2=4.828, P=0.028)in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA( χ2=18.986, P<0.001)and MRCNS( χ2=4.477, P=0.034)in less developed regions(per capita GDP
2.National bloodstream infection bacterial resistance surveillance report (2023) : Gram-negative bacteria
Jinru JI ; Zhiying LIU ; Chaoqun YING ; Qing YANG ; Haishen KONG ; Jiangqin SONG ; Hui DING ; Yanyan LI ; Yuanyuan DAI ; Haifeng MAO ; Pengpeng TIAN ; Lu WANG ; Yongyun LIU ; Yizheng ZHOU ; Jiliang WANG ; Yan JIN ; Donghong HUANG ; Hongyun XU ; Peng ZHANG ; Xinhua QIANG ; Hong HE ; Lin ZHENG ; Junmin CAO ; Zhou LIU ; Ying HUANG ; Yan GENG ; Haiquan KANG ; Dan LIU ; Guolin LIAO ; Lixia ZHANG ; Fenghong CHEN ; Yanhong LI ; Baohua ZHANG ; Haixin DONG ; Xiaoyan LI ; Donghua LIU ; Qiuying ZHANG ; Xuefei HU ; Liang GUO ; Sijin MAN ; Dijing SONG ; Rong XU ; Youdong YIN ; Kunpeng LIANG ; Aiyun LI ; Zhuo LI ; Hongxia HU ; Guoping LU ; Jinhua LIANG ; Qiang LIU ; Yinqiao DONG ; Jilu SHEN ; Shuyan HU ; Liang LUAN ; Jian LI ; Ling MENG ; Dengyan QIAO ; Xiusan XIA ; Bo QUAN ; Dahong WANG ; Chunhua HAN ; Xiaoping YAN ; Fei LI ; Shifu WANG ; Ping SHEN ; Yunbo CHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2025;18(1):47-62
Objective:To report the results of bacterial resistant investigation collaborative system(BRICS)on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023,and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period,11 492 strains of Gram-negative bacteria were collected from 60 hospitals,of which 10 098(87.9%)were Enterobacterales and 1 394(12.1%)were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli(50.0%), Klebsiella pneumoniae(26.1%), Pseudomonas aeruginosa(5.1%), Acinetobacter baumannii complex(5.0%)and Enterobacter cloacae complex(4.1%). The ESBL-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus mirablilis were 46.8%(2 685/5 741),18.3%(549/2 999)and 44.0%(77/175),respectively. The prevalence of carbapenem-resistant Escherichia coli(CREC)and carbapenem-resistant Klebsiella pneumoniae(CRKP)were 1.3%(76/5 741)and 15.0%(450/2 999);32.9%(25/76)and 78.0%(351/450)of CREC and CRKP were sensitive to ceftazidime/avibactam combination,respectively. 94.7%(72/76)and 90.2%(406/450)of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore,57.9%(44/76)and 79.1%(356/450)were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)complex was 64.6%(370/573),while more than 80.0% of CRAB complex was sensitive to tigecycline,eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa(CRPA)was 17.0%(99/581). There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China,with statistically significant differences in the prevalence of CREC,CRKP,CRPA and CRAB complex( χ2=10.6,28.6,10.8 and 19.3, P<0.05). The prevalence of ESBL-producing Escherichia coli, CREC,CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals( χ2=12.5,9.8,12.7 and 57.8,all P<0.01). Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China,and Escherichia coli is ranked in the top,while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend,CREC infecton maintains a low prevalence level,and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.
3.A study on community healthcare workers preferences for providing Traditional Chinese Medicine health management services based on Discrete Choice Experiment
Xiao-jing MA ; Hang XU ; Yu-na PAN ; Jian-ping REN
Chinese Journal of Health Policy 2025;18(3):48-56
Objective:To investigate the preferences and influencing factors of Traditional Chinese Medicine(TCM)health management services among community healthcare workers,providing a reference for promoting and spreading TCM health management services in communities.Methods:Based on a discrete choice experiment,a questionnaire survey was conducted among 596 community healthcare workers across 9 administrative districts in Beijing.A mixed logit model was used to analyze their preferences.Results:Changes in post-tax monthly income,expected efficacy,single-service duration,technical difficulty,patient compliance,and insurance coverage significantly influenced community doctors'service preferences.Changes in post-tax monthly income had the highest relative importance(35.11%),followed by insurance coverage(34.87%).Preferences varied among healthcare workers with different professional titles,backgrounds,weekly working hours,and whether the service was included in performance evaluations.Conclusion:Both economic and non-economic factors influence community healthcare workers'service preferences to varying degrees.Optimizing the combination of TCM health management service attributes can enhance community healthcare workers'willingness to provide such services.It is recommended to use a combination of economic and non-economic incentive measures and develop differentiated strategies for healthcare workers with different characteristics to meet their service preferences and promote the development of TCM health management services in communities.
4.Study on the effectiveness and safety of a novel intravascular shock wave balloon for pre-treatment of severe coronary artery calcification lesions
Rui-tao ZHANG ; Zhen-yu TIAN ; Yong ZENG ; Guo-sheng FU ; Li XU ; Jian LIU ; Jian-ping LI ; Zhi-hui ZHANG ; Xin-qun HU ; Xiang CHENG ; Wen LU ; Ming CUI ; Yi-da TANG
Chinese Journal of Interventional Cardiology 2025;33(2):61-70
Objective To evaluate the efficacy and safety of a novel intravascular lithotripsy(IVL)balloon—Vesscrack shockwave balloon—for vascular preparation before stent implantation in patients with severe coronary artery calcification(CAC).Methods This was a prospective,single-arm,multicenter study conducted in China from June 2022 to October 2022.Patients with severe CAC were treated with the Vesscrack shockwave balloon for lesion preparation,followed by drug-eluting stent(DES)implantation.Of these,33 patients underwent optical coherence tomography(OCT).The primary endpoint was procedural success,defined as successful stent implantation with residual stenosis≤30%and the absence of in-hospital major adverse events,including cardiac death,target vessel-related myocardial infarction,or target lesion revascularization.Results A total of 170 patients[mean age:(65.9±7.9)years,116 males]were enrolled.After treatment with IVL and DES,the minimum lumen diameter increased significantly compared to baseline[(2.34±0.40)mm vs.(0.95±0.33)mm,P<0.001],the degree of stenosis was significantly reduced[(13.24±6.60)%vs.(65.18±10.59)%,P<0.001].Procedural success was achieved in 100%of cases,and device success was 98.8%.The 30-day patient-related cardiovascular clinical composite endpoint(POCE)rate was 0.0,with no target lesion failure,no confirmed or potential thrombotic events were observed.The shockwave energy generator demonstrated excellent stability and ease of use.Among the 33 patients assessed with OCT,after IVL intervention,the maximum calcified area of the lumen[(3.51±1.51)mm2 vs.(2.85±1.80)mm2,P<0.001],and the minimum lumen area within the target lesion[(3.08±1.04)mm2 vs.(2.02±0.75)mm2,P<0.001],and after DES intervention,the luminal area of the largest calcified site[(6.59±1.64)mm2 vs.(2.85±1.80)mm2,P<0.001]and the minimum luminal area within the target lesion[(6.19±1.45)mm2 vs.(2.02±0.75)mm2,P<0.001]were significantly increased,and the differences were statistically significant.Conclusions The Vesscrack shockwave balloon is effective and safe for vascular preparation in patients with severe CAC prior to stent implantation.It achieves significant calcified plaque modification,high procedural success rates,and minimal complications.
5.The value of total volume response and total mass response in the therapeutic evaluation of lung metastasis of hepatocarcinoma
Jun-cheng WAN ; Cai-hong YU ; Chang-yu LI ; Yong-jie ZHOU ; Wei ZHANG ; Jian-hua WANG ; Zhi-ping YAN ; Guo-wei YANG ; Zhuo-yang FAN ; Xu-dong QU
Fudan University Journal of Medical Sciences 2025;52(2):201-208,231
Objective To analyze the correlation between lesion volume,lesion mass,and maximum lesion diameter in the assessment of advanced hepatocarcinoma with lung metastasis,and to evaluate the application value of total volume response and total mass response of lung metastatic lesions in efficacy assessment.Methods A retrospective analysis was conducted on the CT imaging data of 20 patients clinically confirmed with hepatocarcinoma and lung metastases,followed by subsequent follow-up to monitor their survival outcomes.Volume measurement software was used to measure the volume of lesions before and after treatment.We recored lesion diameter,volume measurements and CT values,calculated the mass of the lesions.The correlation between lesion volume,mass and diameter was analyzed,as well as the correlation between the change rates of volume,mass and lesion diameter.Additionally,the total volume and total mass of all lesions were calculated.The correlation between the change rates of total volume/total mass and the change rate of pulmonary lesion diameter under the RECIST 1.1 criteria,as well as the correlation with changes in patients'tumor markers,were analyzed.Furthermore,the overall volume response and overall mass response of lesions were evaluated based on changes in total volume and total mass,and their consistencies with the RECIST 1.1 criteria for efficacy evaluation were analyzed.Finally,univariate Cox regression analysis was performed to explore the association between these variables and patient survival outcomes.Results There was strong correlation between lesion volume,mass and tumor diameter(r=0.771,0.775),between the rate of change in mass and the rate of change in lesion diameter(r=0.846),and between the rates of change in total volume/total mass and the rate of change in pulmonary lesion diameter under the RECIST 1.1 criteria(r=0.800,0.896).The correlation between the rates of change in total volume/total mass and patients'tumor markers was not statistically significant.There was moderate correlation between the rate of change in volume and the rate of change in lesion diameter(r=0.692).The evaluation results of total volume response and total mass response for pulmonary lesions in advanced hepatocarcinoma with lung metastasis were generally consistent with the RECIST 1.1 criteria(Kappa=0.486,0.426).Univariate Cox regression analysis revealed that total lesion volume(P=0.047)and total lesion mass(P=0.049)were independent prognostic factors for survival outcomes.Conclusion Lesion volume,mass,and diameter,as well as their respective change rates,were found to be interrelated.Furthermore,total lesion volume and total lesion mass were identified as independent prognostic factors for survival outcomes.The total volume response and total mass response are promising evaluation methods in evaluating the efficacy of lung metastasis of hepatocarcinoma,which are different from the RECIST 1.1 evaluation criteria.
6.Development of Bismuth Iodide Oxide/Nitrogen-doped Graphene Quantum Dots-based Photoelectrochemical Sensor for Determination of Chlorpyrifos
Ya-Fei CHEN ; Xu-Hui ZHANG ; Guang-Wei YANG ; Xiao-Ping WEI ; Jian-Ping LI
Chinese Journal of Analytical Chemistry 2025;53(3):364-374
Bismuth iodide(BiOI)with different crystal plane ratios of(110)to(001)was synthesized,and typeⅡheterojunction formed between(001)and(110)crystal planes of BiOI was used to improve the separation efficiency of photogenerated electrons and holes.Then the BiOI(001)/(110)was composited with nitrogen-doped graphene quantum dots(N-GQDs)to prepare a ternary composites,which could enhance the range and intensity of light absorption,and prolonged the lifetime of photogenerated electrons due to the formation of Z-scheme heterojunctions between BiOI and N-GQDs,thereby leading to the excellent photoelectric performance of the BiOI/N-GQDs for generating sensitive photoelectric response signals.A photoelectrochemical sensor for sensitive detection of chlorpyrifos(CPF)was designed with BiOI/N-GQDs-modified FTO electrode as a photocathode.The S and N atoms contained in CPF were coordinated with Bi(Ⅲ)on the surface of BiOI,which reduced the photocurrent of BiOI/N-GQDs.The photocurrent change was linear with logarithm of concentration of CPF in the range of 1.5×10-12-5.0×10-9 mol/L,and the detection limit was 1.5×10-12 mol/L.The sensor was highly sensitive,selective and stable,and could be used for determination of trace CPF in environmental and food samples.
7.Study on Colorimetric Sensor Array Based on Enzymatic Method for Highly Selective Detection of Sarin
Lian-Bo JIANG ; Guo-Hong LIU ; Zhuang-Hu XU ; Jian LI ; Yong-Ling SHEN ; Cai-Xia XU ; Chuan-Qin ZANG ; Yan-Hua XIAO ; Dan-Ping LI ; Ting LIANG
Chinese Journal of Analytical Chemistry 2025;53(5):832-841,中插21-中插23
Sarin(GB)is a typical representative of nerve agents with high toxicity,and very low amount can cause death.GB can cause water and atmospheric environment poisoning,so the detection of GB in water and air is of great significance.In this work,a colorimetric sensor array(CSA)based on GB inhibition of cholinesterase activity was constructed to detect GB with high selectivity.A 4×4 colorimetric array was constructed using acetylcholinesterase(AChE),butyryl cholinesterase(BuChE)and the corresponding substrate acetylthiocholine iodide(S-ACh),butyryl thiocholine iodide(S-BCh),acetylcholine chloride(ACh),butyryl choline chloride(BCh)and 2,6-dichloroindophenol ethyl ester(DCIE).The linear curve of the sensor was Y=131.3×lgC+271.6(R2=0.997),where Y was the array response Euclidean distance,C was the concentration of GB(mg/L),the linear range was 0.03?0.32 mg/L,and the detection limit was 27.6 μg/L.The method could effectively distinguish chemical warfare agents(CWA)such as VX,Soman(GD),mustard gas(HD),Louie reagent(L),and had high anti-interference ability,sensitivity and good repeatability.It was successfully applied to the detection of GB in simulated water and simulated air samples,and the sample recovery rate was 97.2% ?100.9%.This method would be potentially applied to the field rapid detection of nerve agents.
8.Investigation of tumor-suppressive mechanism of Guiqi Yiyuan Extract combined with cisplatin in Lewis lung cancer mice via TXNIP/NLRP3/Caspase-1/GSDMD pathway
Qiong-qiong GUO ; Wen-jie LI ; Jin-tian LI ; Jian-qing LIANG ; Ping TIAN ; Rong HU ; Xu-chao DONG ; Mei-hao XUE ; Long-xin XU
Chinese Traditional Patent Medicine 2025;47(9):2894-2901
AIM To investigate the tumor-suppressive mechanism of Guiqi Yiyuan Extract combined with cisplatin in Lewis lung cancer mice.METHODS Ten intact C57BL/6J mice were assigned to the blank group.Sixty additional mice were developed into Lewis lung cancer models bearing transplanted tumor and subsequently allocated into the model group,the cisplatin group(5 mg/kg),the high-dose Guiqi Yiyuan Extract group(6.6 g/kg),and the low-dose,medium-dose and high-dose Guiqi Yiyuan Extract combined with cisplatin group(1.6,3.3,6.6 g/kg+5 mg/kg),with 10 mice in each group.Mice in the blank and model groups received saline via daily gavage,while treatment groups were administered Guiqi Yiyuan Extract orally(once daily),and cisplatin injection intraperitoneally(once every other day).After 14 days of drug administration,mice were euthanized for endpoint analysis.The following assessments were conducted:general health status and body weight changes monitored throughout the study period;tumor excision and weighing for inhibition rate calculation;histopathological examination of tumors via hematoxylin-eosin(HE)staining;serum quantification of IL-1 β,IL-18 and HMGB1 by ELISA;ultrastructural analysis of tumor cell death using transmission electron microscopy(TEM);spatial localization of TXNIP and GSDMD-N in tumor sections via immunofluorescence(IF);and Western blot detection of TXNIP,NLRP3,Caspase-1,cleaved Caspase-1,GSDMD,GSDMD-N protein expressions in tumor tissues.RESULTS Compared to the model group,the cisplatin group and all combination therapy groups exhibited significant reduction in tumor weight(P<0.05)and increased tumor suppression rate;enhanced tumor tissue necrosis with characteristic pyroptotic morphology;elevated serum levels of IL-1β,IL-18 and HMGB1(P<0.05);and upregulated expressions of pyroptosis-associated proteins TXNIP,NLRP3,Caspase-1,cleaved Caspase-1,GSDMD and GSDMD-N(P<0.05).The high dose combination group demonstrated optimal therapeutic efficacy(P<0.05).CONCLUSION Guiqi Yiyuan Extract enhances cisplatin sensitivity,demonstrating synergistic anti-tumor effects in Lewis lung carcinoma-bearing mice.This combinatorial therapeutic effect likely involves modulation of the TXNIP/NLRP3/Caspase-1/GSDMD pathway.
9.Effects of Hugan Tablets on autophagy,pyroptosis and PI3K/Akt/mTOR signaling pathway in a mouse model of non-alcoholic fatty liver disease
Rui-hua WANG ; Lan-wei HUANG ; Lie-ming XU ; Jian PING
Chinese Traditional Patent Medicine 2025;47(3):766-773
AIM To observe the effects of Hugan Tablets on high-fat diet induced non-alcoholic fatty liver disease(NAFLD)in a mouse model,and the autophagy,pyroptosis and the PI3K/Akt/mTOR signaling pathway as well.METHODS The C57BL/6 mice were randomly divided into the normal group,the model group,the Hugan Tablets group(0.7 g/kg)and the Yishanfu group(0.23 g/kg),with 10 mice in each group.The NAFLD mouse model was established by 16 weeks feeding of high-fat diet.From the 13th week,the mice started their corresponding dosing of the drug by gavage followed by killing of the mice at the end of 16th week and collection of their serum and liver tissue samples.The mice had their serum ALT,AST,TG,TC,LDL levels,liver TG,TC,NEFA,MDA levels and activities of SOD and GSH-Px detected;their serum levels of IL-1β,IL-6 and TNF-αdetected by ELISA;their hepatic pathological changes observed using HE staining and oil red O staining;and their hepatic protein expressions of ACC,CPT1A,FAS,p-PI3K,p-Akt,p-mTOR,P62,LC3,NLRP3,GSDMD and Caspase1 detected by Western blot.RESULTS Compared with the model group,the Hugan Tablets group displayed decreased body weight and hepatosmatic index level(P<0.01);decreased levels of serum ALT,AST,TG,TC,LDL,IL-6,IL-1β and TNF-α(P<0.05,P<0.01);increased hepatic levels of TG,TC,NEFA and MDA(P<0.05);decreased activities of SOD and GSH-Px(P<0.05);improved pathological changes of hepatic lipid deposition and hepatocytic ballooning and decreased NAS score and oil red O staining area(P<0.01);decreased hepatic protein expressions of ACC1,FAS,NLRP3,Caspase1,GSDMD,P62,p-PI3K,p-Akt and p-mTOR(P<0.05,P<0.01);and increased protein expressions of CPT1A and LC3(P<0.01).CONCLUSION Hugan Tablets can effectively prevent and control the development of high-fat diet induced NAFLD in mice,and the mechanism may be associated with the promotion of autophagy in hepatocytes and the inhibition of pyroptosis via the inhibition of PI3K/Akt/mTOR signaling pathway.
10.Epidemiological and genetic characteristics of school influenza outbreaks in Changzhou from 2021 to 2024
Qiong LI ; Jingyi JIANG ; Li GONG ; Jian XU ; Xujian MAO ; Fengming WANG ; Ping YAO
Chinese Journal of Experimental and Clinical Virology 2025;39(5):617-622
Objective:To characterize the etiological and genetic features of pediatric influenza outbreaks in Changzhou between 2021 and 2024,with the goal of informing evidence-based prevention strategies and guiding effective management of influenza outbreaks in school settings.Methods:During the period of 2021 to 2024,throat swabs of influenza-like cases from school outbreaks in Changzhou were collected. These samples underwent real-time reverse transcription-polymerase chain reaction(RT-PCR)testing and virus isolation. Epidemiological data were integrated to conduct pathogenetic analysis. The HA genes of isolated strains were amplified and sequenced to perform genetic characterization.Results:Between 2021 and 2024,a total of 256 influenza outbreaks were reported in schools in Changzhou. A total of 3 201 specimens were collected,of which 2 245 were tested positive for influenza viruses,resulting in a positivity rate of 70.13%. The outbreak season was primarily concentrated from December to February each year,with settings predominantly distributed in primary schools(accounting for 73.83%). The predominant epidemic strains were influenza A viruses,including 118 outbreaks caused by H1N1 and 104 by H3N2. A total of 74 influenza virus strains were successfully isolated from positive specimens,and sequencing of the hemagglutinin(HA)gene was completed. Phylogenetic analysis revealed that certain B/Victoria lineage strains(e.g.,B/Changzhou/01/2021)clustered closely with the vaccine strain B/Austria/3594/17(bootstrap support:99%). Among influenza H1N1 strains,multiple isolates from 2023—2024 clustered within the same major branch as A/Victoria/4897/2022(bootstrap support:100%). In contrast,the H3N2 strains exhibited a complex evolutionary pattern,showing variable genetic distances to vaccine strains from different years(e.g.,A/Massachusetts/18/2022,A/Darwin/6/2021);some isolates were closely related to vaccine strains,while others were more distantly related and scattered across the phylogenetic tree.Conclusions:The influenza outbreak situation in schools was severe and has significant public health implications. Continuous surveillance is essential,and preventive strategies should be promptly adjusted based on the epidemiological and genetic characteristics of circulating strains.

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