BACKGROUND:Spleen has the functions of blood storage,hematopoiesis,and immunity.With the increase of age,the structural degeneration and functional decline of spleen lead to the impairment of immune system function,thus accelerating the aging process of the body.The treatment of spleen aging in tree shrews with highly active umbilical cord mesenchymal stem cells has not been reported. OBJECTIVE:To explore the intervention effect and mechanism of highly active umbilical cord mesenchymal stem cells on spleen aging in tree shrews. METHODS:Highly active umbilical cord mesenchymal stem cells were isolated,cultured,and obtained from the umbilical cord tissue of newborn tree shrews by caesarean section.The differentiation abilities of adipogenesis,osteogenesis,and chondrogenesis were detected by three-line differentiation kit.Cell cycle and surface markers were detected by flow cytometry.The second generation of highly active umbilical cord mesenchymal stem cells were transfected with Genechem Green Fluorescent Protein with infection complex values of 100,120,140,160,180,and 200,respectively,to screen the best transfection conditions.After transfection,the fourth generation of highly active umbilical cord mesenchymal stem cells was injected into the tail vein of tree shrews in the elderly treatment group.The young control group and the aged model group were not given special treatment.After 4 months of treatment,the spleen tissue was taken and the structure of the spleen was observed by hematoxylin-eosin staining.β-Galactosidase staining was used to detect the activity of aging-related galactosidase.Immunohistochemical staining was used to detect the expression levels of p21 and p53 proteins.Ki67 and PCNA immunofluorescence staining was used to detect cell proliferation activity.Immunofluorescence staining was used to detect the expression levels of spleen autophagy protein molecules Beclin 1 and APG5L/ATG5.Reactive oxygen species fluorescence staining was used to detect the content of reactive oxygen species in spleen tissue.CD3 immunofluorescence staining was used to detect the change of the proportion of total T lymphocytes.The secretion levels of interleukin 1β and transforming growth factor β1 in spleen were detected by enzyme linked immunosorbent assay.The distribution of highly active umbilical cord mesenchymal stem cells labeled with green fluorescent protein in spleen tissue was observed by DAPI double staining of nucleus. RESULTS AND CONCLUSION:(1)Highly active umbilical cord mesenchymal stem cells grew in a short spindle shape with fish-like growth,with a large proportion of G0/G1 phase,and had the potential to differentiate into adipogenesis,osteogenesis,and chondrogenesis.(2)Multiplicity of infection=140 and transfection for 72 hours were the best conditions for labeling tree shrews highly active umbilical cord mesenchymal stem cells with Genechem Green Fluorescent Protein.(3)Compared with the aged model group,in the aged treatment group,the spleen tissue cells of tree shrews were arranged closely,and the area of white pulp was increased(P<0.01);the boundary between red pulp and white pulp was clear;the proportion of germinal centers did not show statistically significant difference(P>0.05).The activity level of galactosidase related to spleen tissue aging was decreased(P<0.001),and the expression levels of aging protein molecules p21 and p53 were down-regulated(P<0.001).The expression levels of proliferation-related molecules Ki67 and PCNA were up-regulated(P<0.001,P<0.05);expression levels of autophagy-related molecules Beclin 1 and APG5L/ATG5 were up-regulated(P<0.001),and the content of reactive oxygen species decreased(P<0.001),and the proportion of CD3+T cells increased(P<0.05).The secretion level of interleukin 1β in the aging-related secretion phenotype decreased(P<0.001);no significant difference was found in transforming growth factor β1 level(P>0.05).Compared with the young control group,the above indexes were significantly different in the elderly treatment group(P<0.05).(4)Green fluorescent cells labeled with green fluorescent protein were observed in spleen tissue of tree shrews the elderly treatment group by frozen tissue section observation.The results show that intravenous infusion of highly active umbilical cord mesenchymal stem cells can migrate to spleen tissue,inhibit the production of reactive oxygen species,down-regulate the expression of aging-related proteins,induce autophagy,promote cell proliferation,reduce chronic inflammation,and then improve the structure and function of spleen tissue.

ObjectiveTo investigate the variation of drug resistance genes in human immunodeficiency virus (HIV)-1 strains in Huzhou City, Zhejiang Province, so as to provide a basis for guiding the adjustment of treatment plans for ADIS patients or patients infected with HIV. MethodsA total of 555 samples were collected from 396 newly diagnosed HIV/AIDS patients who did not receive antiviral treatment from 2021 to 2023, in addition to 159 HIV/AIDS patients who received antiviral treatment for at least twelve months but failed during the same period.Reverse transcription polymerase chain reaction (RT-PCR) and nested polymerase chain reaction (nested PCR) were used to amplify the pol region gene of HIV-1. Lastly, the sequenced data were submitted to the HIV resistance database of Stanford University in the United States for resistance gene mutation analysis. ResultsDrug resistance mutations were detected in samples from 97 newly diagnosed HIV/AIDS patients and 77 patients with failed treatment, with the main subtypes being CRF01AE and CRF07-BC. The mutation rates of drug resistance genes in the patients untreated and patients with failed treatment were 24.49% (97/396) and 48.43% (77/159), respectively. Drug resistance gene mutations against protease inhibitor (PI), nucleotide reverse transcriptase inhibitor (NRTI), and non-nucleoside reverse transcriptase inhibitor (NNRTI) were detected both in the untreated and failed treatment group. The drug resistance rates of untreated and failed treatment patients were 10.61% (42/396) and 45.28% (72/159), respectively. ConclusionThe pre-treatment drug resistance rate of HIV-1 strains in Huzhou City is at a moderate level, and which is at a relatively low level nationwide after antiviral treatment. The resistance genes in the region exhibit diverse and complex characteristics, and the prevalence of drug resistance is in the process of upward and evolution compared to the monitoring results in the previous years. It is necessary to continue to monitor the occurrence and development of drug resistant strains, and to adjust treatment plans in time to prevent the occurrence of transmissible drug resistance.

Objective To investigate the prevalence of Schistosoma japonicum infections in wild rodents in schistosomiasis-endemic areas of China, so as to provide insights into formulation of technical guidelines for monitoring of and the precise control strategy for S. japonicum infections in wild rodents during the elimination phase. Methods Two administrative villages where schistosomiasis was historically highly prevalent were selected each from Dongzhi County, Anhui Province, and Duchang County, Jiangxi Province as study villages. Wild rodents were captured from study villages with baited traps or cages at night in June and September, 2021. The number of rodents captured was recorded, and the rodent species was characterized based on morphologi-cal characteristics. Liver tissues were sampled from captured rodents for macroscopical observation of the presence of egg granu- lomas, and S. japonicum infection was detected simultaneously using liver tissue homogenate microscopy, examinations of mesenteric tissues for parasites, and modified Kato-Katz thick smear technique (Kato-Katz technique). A positive S. japonicum infection was defined as detection of S. japonicum eggs or adult worms by any of these methods. The rate of wild rodent capture and prevalence of S. japonicum infections in wild rodents were compared in different study villages and at different time periods, and the detection of S. japonicum infections in wild rodents was compared by different assays. Results The overall rate of wild ro- dent capture was 8.28% (237/2 861) in Dongzhi County, and the wild rodent capture rates were 9.24% (133/1 439) and 7.31% (104/1 422) in two study villages (χ² = 3.503, P = 0.061), and were 8.59% (121/1 409) and 7.99% (116/1 452) in June and September, 2021, respectively (χ² = 0.337, P = 0.561). The overall rate of wild rodent capture was 3.72% (77/2 072) in Duchang County, and the wild rodent capture rates were 6.91% (67/970) and 0.91% (10/1 102) in two study villages (χ² = 51.901, P < 0.001), and were 4.13% (39/945) and 3.37% (38/1 127) in June and September, 2021, respectively (χ² = 0.815, P = 0.365). Rattus norvegicus was the predominant rodent species captured in both counties, accounting for 70.04% (166/237) of all captured wild rodents in Dongzhi County and 88.31% (68/77) in Duchang County. No S. japonicum infection was detected in wild rodents captured in Duchang County. Nevertheless, the overall prevalence of S. japonicum infections was 51.05% (121/237) in wild rodents captured in Dongzhi County, with prevalence rates of 50.38% (67/133) and 51.92% (54/104) in two study villages (χ² = 0.098, P = 0.755), and 54.31% (63/116) and 47.93% (58/121) in September and June, 2021, respectively (χ² = 0.964, P = 0.326). Of 237 wild rodents captured in Dongzhi County, there were 140 (59.07%) rodents with visible hepatic egg granulomas, 117 (49.47%) tested positive for S. japonicum eggs by liver tissue homogenate microscopy, 34 (14.35%) tested positive for S. japonicum eggs with Kato-Katz technique; however, no adult S. japonicum worms were detected in mesenteric tissues. In addition, hepatic egg granulomas were found in all wild rodents tested positive for S. japonicum eggs with liver tissue homogenate microscopy. Conclusions The rate of wild rodent capture and prevalence of S. japonicum infection in wild rodents vary greatly in schistosomiasis-endemic areas of China, and the prevalence of S. japonicum infection is slightly higher in wild rodents captured in autumn than in summer. Liver tissue is recommended as the preferred sample for surveillance of S. japonicum infection in wild rodents, and a combination of macroscopical observation of hepatic egg granulomas and liver tissue homogenate microscopy may be a standard method for surveillance of S. japonicum infection in wild rodents.

Objective To investigate the influencing factors of pulmonary and extrapulmonary acute re-spiratory distress syndrome(ARDS)caused by sepsis.Methods A total of 126 patients with ARDS admitted to the Department of Critical Care Medicine,General Hospital of Ningxia Medical University,from January 2022 to June 2024 were selected.Patients were divided into pulmonary ARDS and extrapulmonary ARDS groups based on the etiology of ARDS.General data,inflammatory indicators,and prognostic outcomes were compared between the two groups.COX regression analysis was used to identify prognostic factors.Results A-mong the 126 patients,72 were diagnosed with pulmonary ARDS and 54 with extrapulmonary ARDS.The pulmonary ARDS group had significantly lower SOFA scores,fewer organ dysfunctions,a lower incidence of arrhythmia,shorter mechanical ventilation duration,higher Murray scores,and higher Charlson Comorbidity Index(CCI)compared to the extrapulmonary ARDS group(P<0.05).Inflammatory markers,including pro-calcitonin(PCT),C-reactive protein(CRP),interleukin(IL)-4,IL-6,IL-10,and tumor necrosis factor-α(TNF-α),were significantly lower in the pulmonary ARDS group,while interferon-γ(INF-γ)levels were higher(P<0.05).For pulmonary ARDS,CCI and TNF-α were identified as independent risk factors for prog-nosis(P<0.05),with the combination of CCI and TNF-α yielding the highest predictive accuracy(AUC=0.81,95%CI:0.71-0.91).For extrapulmonary ARDS,CCI and CRP were independent risk factors(P<0.05),and their combination achieved the highest predictive performance(AUC=0.91,95%CI:0.84-0.98).Conclusion Inflammatory profiles between pulmonary and extrapulmonary ARDS caused by sepsis are different.CCI and TNF-α are independent risk factors for mortality in pulmonary ARDS,while CCI and CRP are independent risk factors in extrapulmonary ARDS.

BACKGROUND:Previous literature reported that the fusion cage moved more than 2 mm from its original position,which means that the fusion cage moved backward.At present,clinical observation has found that the factors leading to the displacement of the fusion cage are complex,and the relationship between these factors and the cage retropulsion is not clear. OBJECTIVE:To explore the risk factors related to cage retropulsion after lumbar interbody fusion. METHODS:Retrospective analysis was conducted in 200 patients who underwent transforaminal lumbar interbody fusion surgery with a polyetheretherketone interbody fusion from February 2020 to February 2022.According to the distance from the posterior edge of the vertebral fusion cage to the posterior edge of the vertebral body after the operation(the second day after the removal of the drainage tube)and 1,3,6 and 12 months after the operation,patients were divided into cage retropulsion group(≥2 mm)and cage non-retropulsion group(<2 mm).The factors that may affect cage retropulsion,such as age,gender,body mass index,bone mineral density,operation time,bleeding,endplate injury,preoperative and postoperative interbody height,cage implantation depth,cage size,and segmental anterior convexity angle,were analyzed by univariate and logistic regression analysis. RESULTS AND CONCLUSION:(1)Posterior displacement of the fusion cage occurred in 15 cases(15/200).The differences in basic information such as age and body mass index between the two groups were not statistically significant.(2)The results of the univariate analysis were that gap height difference,time to wear a brace,segmental anterior convexity angle difference,bone mineral density,and age were related to posterior migration of the cage.(3)The results of logistic regression analysis were that cage size,endplate injury condition,and depth of cage implantation were risk factors for cage retropulsion.(4)These findings suggest that cage retropulsion after lumbar interbody fusion is caused by multiple factors,including segmental anterior convexity angle difference,bone mineral density,cage size,endplate damage,time to wear a brace,and depth of cage implantation.

【Objective】 To establish a blood quality monitoring indicator system, in order to continuously improve blood quality and standardized management. 【Methods】 Based on the research of literature and standards, and guided by the key control points of blood collection and supply process, the blood quality monitoring indicator system was developed. Through two rounds of Delphi expert consultation, the indicator content was further revised and improved according to expert opinions after six months of trial implementation. The indicator weight was calculated by questionnaire and analytic hierarchy process. 【Results】 A blood quality monitoring indicator system covering the whole process of blood collection and supply was constructed, including five primary indicators, namely blood donation service, blood component preparation, blood testing, blood supply and quality control, as well as 72 secondary indicators, including definitions, calculation formulas, etc. Two rounds of expert consultation and two rounds of feasibility study meeting were held to revise 17 items and the weight of each indicator was obtained through the analytic hierarchy process. After partial adjustments, a blood quality monitoring indicator system was formed. 【Conclusion】 A blood quality monitoring indicator system covering the whole process of blood collection and supply has been established for the first time, which can effectively evaluate the quality management level of blood banks and coordinate blood quality control activities of blood banks in Shandong like pieces in a chess game, thus improving the standardized management level

【Objective】 To objectively evaluate the quality control level of blood testing process in blood banks through quantitative monitoring and trend analysis, and to promote the homogenization level and standardized management of blood testing laboratories in blood banks. 【Methods】 A quality monitoring indicator system covering the whole process of blood collection and supply, including blood donation service, blood component preparation, blood testing, blood supply and quality control was established. The questionnaire Quality Monitoring Indicators for Blood Collection and Supply Process with clear definition of indicators and calculation formulas was distributed to 17 blood banks in Shandong province. Quality monitoring indicators of each blood bank from January to December 2022 were collected, and 31 indicators in terms of blood testing were analyzed using SPSS25.0 software. 【Results】 The proportion of unqualified serological tests in 17 blood bank laboratories was 55.84% for ALT, 13.63% for HBsAg, 5.08% for anti HCV, 5.62% for anti HIV, 18.18% for anti TP, and 1.65% for other factors (mainly sample quality). The detection unqualified rate and median were (1.23±0.57)% and 1.11%, respectively. The ALT unqualified rate and median were (0.74±0.53)% and 0.60%, respectively. The detection unqualified rate was positively correlated with ALT unqualified rate (r=0.974, P<0.05). The unqualified rate of HBsAg, anti HCV, anti HIV and anti TP was (0.15±0.09)%, (0.05±0.04)%, (0.06±0.03)% and (0.20±0.05)% respectively. The average unqualified rate, average hemolysis rate, average insufficient volume rate and the abnormal hematocrit rate of samples in 17 blood bank laboratories was 0.21‰, 0.08‰, 0.01‰ and 0.02‰ respectively. There were differences in the retest concordance rates of four HBsAg, anti HCV and anti HIV reagents, and three anti TP reagents among 17 blood bank laboratories (P<0.05). The usage rate of ELISA reagents was (114.56±3.30)%, the outage rate of ELISA was (10.23±7.05) ‰, and the out of range rate of ELISA was (0.90±1.17) ‰. There was no correlation between the out of range rate, outrage rate and usage rate (all P>0.05), while the outrage rate was positively correlated with the usage rate (r=0.592, P<0.05). A total of 443 HBV DNA positive samples were detected in all blood banks, with an unqualified rate of 3.78/10 000; 15 HCV RNA positive samples were detected, with an unqualified rate of 0.13/10 000; 5 HIV RNA positive samples were detected, with an unqualified rate of 0.04/10 000. The unqualified rate of NAT was (0.72±0.04)‰, the single NAT reaction rate [(0.39±0.02)‰] was positively correlated with the single HBV DNA reaction rate [ (0.36±0.02) ‰] (r=0.886, P<0.05). There was a difference in the discriminated reactive rate by individual NAT among three blood bank laboratories (C, F, H) (P<0.05). The median resolution rate of 17 blood station laboratories by minipool test was 36.36%, the median rate of invalid batch of NAT was 0.67%, and the median rate of invalid result of NAT was 0.07‰. The consistency rate of ELISA dual reagent detection results was (99.63±0.24)%, and the median length of equipment failure was 14 days. The error rate of blood type testing in blood collection department was 0.14‰. 【Conclusion】 The quality monitoring indicator system for blood testing process in Shandong can monitor potential risks before, during and after the experiment, and has good applicability, feasibility, and effectiveness, and can facilitate the continuous improvement of laboratory quality control level. The application of blood testing quality monitoring indicators will promote the homogenization and standardization of blood quality management in Shandong, and lay the foundation for future comprehensive evaluations of blood banks.

【Objective】 To establish an effective quality monitoring indicator system for blood quality control in blood banks, in order to analyze the quality control indicators for blood collection and supply, and evaluate blood quality control process, thus promoting continuous improvement and standardizing management of blood quality control in blood banks. 【Methods】 A quality monitoring indicator system covering the whole process of blood collection and supply, including blood donation services, component preparation, blood testing, blood supply and quality control was established. The Questionnaire of Quality Monitoring Indicators for Blood Collection and Supply Process was distributed to 17 blood banks in Shandong, which clarified the definition and calculation formula of indicators. The quality monitoring indicator data from January to December 2022 in each blood bank were collected, and 20 quality control indicators data were analyzed by SPSS25.0 software. 【Results】 The average pass rate of key equipment monitoring, environment monitoring, key material monitoring, and blood testing item monitoring of 17 blood banks were 99.47%, 99.51%, 99.95% and 98.99%, respectively. Significant difference was noticed in the pass rate of environment monitoring among blood banks of varied scales(P<0.05), and the Pearson correlation coefficient (r) between the total number of blood quality testing items and the total amount of blood component preparation was 0.645 (P<0.05). The average discarding rates of blood testing or non-blood testing were 1.14% and 3.36% respectively, showing significant difference among blood banks of varied scales (P<0.05). The average discarding rate of lipemic blood was 3.07%, which had a positive correlation with the discarding rate of non testing (r=0.981 3, P<0.05). There was a statistically significant difference in the discarding rate of lipemic blood between blood banks with lipemic blood control measures and those without (P<0.05). The average discarding rate of abnormal color, non-standard volume, blood bag damage, hemolysis, blood protein precipitation and blood clotting were 0.20%, 0.14%, 0.06%, 0.06%, 0.02% and 0.02% respectively, showing statistically significant differences among large, medium and small blood banks(P<0.05).The average discarding rates of expired blood, other factors, confidential unit exclusion and unqualified samples were 0.02%, 0.05%, 0.003% and 0.004%, respectively. The discarding rate of blood with air bubbles was 0.015%, while that of blood with foreign body and unqualified label were 0. 【Conclusion】 The quality control indicator system of blood banks in Shandong can monitor weak points in process management, with good applicability, feasibility, and effectiveness. It is conducive to evaluate different blood banks, continuously improve the quality control level of blood collection and supply, promote the homogenization and standardization of blood quality management, and lay the foundation for comprehensive evaluation of blood banks in Shandong.

【Objective】 To establish an effective quality indicator monitoring system, scientifically and objectively evaluate the quality management level of blood banks, and achieve continuous improvement of quality management in blood bank. 【Methods】 A quality monitoring indicator system that covers the whole process of blood collection and supply was established, the questionnaire of Quality Monitoring Indicators for Blood Collection and Supply Process with clear definition of indicators and calculation formulas was distributed to 17 blood banks in Shandong. Statistical analysis of 21 quality monitoring indicators in terms of blood donation service (10 indicators), blood component preparation (7 indicators ), and blood supply (4 indicators) from each blood bank from January to December 2022 were conducted using SPSS25.0 software The differences in quality monitoring indicators of blood banks of different scales were analyzed. 【Results】 The average values of quality monitoring indicators for blood donation service process of 17 blood banks were as follows: 44.66% (2 233/5 000) of regular donors proportion, 0.22% (11/50) of adverse reactions incidence, 0.46% (23/5 000) of non-standard whole blood collection rate, 0.052% (13/25 000) of missed HBsAg screening rate, 99.42% (4 971/5 000) of first, puncture successful rate, 86.49% (173/200) of double platelet collection rate, 66.50% (133/200) of 400 mL whole blood collection rate, 99.25% (397/400) of donor satisfaction rate, 82.68% (2 067/2 500) of use rate of whole blood collection bags with bypass system with sample tube, and 1 case of occupational exposure in blood collection.There was a strong positive correlation between the proportion of regular blood donors and the collection rate of 400 mL whole blood (P<0.05). The platelet collection rate, incidence of adverse reactions to blood donation, and non-standard whole blood collection rate in large blood banks were significantly lower than those in medium and small blood banks (P<0.05). The average quality monitoring indicators for blood component preparation process of 17 blood banks were as follows: the leakage rate of blood component preparation bags was 0.03% (3/10 000), the discarding rate of lipemic blood was 3.05% (61/2 000), the discarding rate of hemolysis blood was 0.13%(13/10 000). 0.06 case had labeling errors, 8 bags had blood catheter leaks, 2.76 bags had blood puncture/connection leaks, and 0.59 cases had non-conforming consumables. The discarding rate of hemolysis blood of large blood banks was significantly lower than that of medium and small blood banks (P<0.05), and the discarding rate of lipemic blood of large and medium blood banks was significantly lower than that of small blood banks (P<0.05). The average values of quality monitoring indicators for blood supply process of 17 blood banks were as follows: the discarding rate of expired blood was 0.023% (23/100 000), the leakage rate during storage and distribution was of 0.009%(9/100 000), the discarding rate of returned blood was 0.106% (53/50 000), the service satisfaction of hospitals was 99.16% (2 479/2 500). The leakage rate of blood components during storage and distribution was statistically different with that of blood component preparation bags between different blood banks (P<0.05). There were statistically significant differences in the proportion of regular blood donors, incidence of adverse reactions, non-standard whole blood collection rate, 400 mL whole blood collection rate, double platelet collection rate, the blood bag leakage rate during preparation process, the blood components leakage rate during storage and distribution as well as the discarding rate of lipemic blood, hemolysis blood, expired blood and returned blood among large, medium and small blood banks (all P<0.05). 【Conclusion】 The establishment of a quality monitoring indicator system for blood donation services, blood component preparation and blood supply processes in Shandong has good applicability, feasibility and effectiveness. It can objectively evaluate the quality management level, facilitate the continuous improvement of the quality management system, promote the homogenization of blood management in the province and lay the foundation for future comprehensive evaluation of blood banks.

ObjectiveTo analyze the characteristics of HIV-1 molecular network and pretreatment drug resistance genes in the middle-aged and elderly people aged ≥50 years in Huzhou City, Zhejiang Province, and to provide an evidence for the prevention and control of AIDS epidemic. MethodsA total of 332 samples from the newly reported and untreated AIDS patients aged ≥50 years in Huzhou City from January 2020 to December 2023 were collected, pol genes were amplified by reverse transcription polymerase chain reaction (RT-PCR) and nested polymerase chain reaction (nest⁃PCR). Phylogenetic trees analyzing the subtypes were constructed, and a molecular network with a gene distance threshold of 1.0% were constructed at the same time. Mutation sites of drug resistance-related genes were identified through the Data Analysis and Detection System of HIV-1 Resistance Gene Detection of Stanford University, USA. ResultsSequence samples of 308 patients were obtained, and9 genotypes were identified, including CRF07_BC in 172 cases (55.8%), CRF01_AE in 61 cases (19.8%), CRF08_BC in 43 cases (14.0%), CRF85_BC in 9 cases (2.9%), and CRF55_01B in 8 cases (2.6%), subtype B in 5 cases (1.6%), subtype C in 4 cases (1.3%), CRF67_01B in3 cases (1.0%), and unique recombination URF01_AE/07_BC in 3 cases (1.0%). When the gene distance threshold was 1.0%, 28 molecular clusters were formed, and 139 cases were connected to the network, with an access rate of 45.0%. The largest transmission cluster C1 contained 44 cases infected with CRF07_BC subtype, all of whom were heterosexually transmitted, and predominantly by males. A total of 30 patients were found to have low-grade or higher drug resistance mutations, and the pretreatment drug resistance rate was 9.7% (30/308). Among them, there were 5 cases (16.7%) of protease inhibitor (PI) related drug resistance mutations, and 26 cases (86.7%) of non-nucleoside reverse transcriptase inhibitors (NNRTI) related drug resistance mutations. ConclusionCRF07_BC is the subtype with the most clusters among the middle-aged and elderly infected patients aged ≥50 years in Huzhou City. Middle-aged and elderly transmission clusters are formed within the three counties of WX, NX and CX through related activities. Molecular network monitoring on newly reported cases aged ≥50 years in Huzhou City should be strengthened so that the new characteristics of epidemic changes can be detected in time, providing a scientific basis for adjusting AIDS prevention and control measures for the elderly.