Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

ObjectiveTo investigate the incidence rate of primary liver cancer （PLC） and the progression of liver fibrosis in chronic hepatitis B （CHB） patients with low-level viremia （LLV） （HBV DNA<2 000 IU/mL but ≥20 IU/mL） after treatment adjustment， and to provide more robust evidence for clinical practice. MethodsA retrospective analysis was performed for the clinical data of LLV patients who initially received nucleos（t）ide analogue （NAs） for at least 48 weeks at the Fifth Medical Center of PLA General Hospital from August 2007 to April 2017 and subsequently underwent NAs adjustment due to LLV， and according to the virologic response after 48 weeks of treatment adjustment， the patients were divided into LLV group and complete virological response （CVR） group （HBV DNA<20 IU/mL）. The patients were followed up once every 3‍ ‍—‍ ‍6 months till the primary endpoint event of PLC or October 2024. The incidence rate of PLC and the progression of liver fibrosis were observed， and the progression of liver fibrosis was defined as an increase of ≥1 grade in fibrosis-4 （FIB-4） index. The independent-samples t test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of continuous data with skewed distribution between two groups； the chi-square test was used for comparison of categorical data between groups. The Kaplan-Meier method was used to calculate the cumulative incidence rate of PLC， and the Log-rank test was used for comparison between groups； the Cox regression analysis was used to investigate the risk factors for PLC， and the Logistic regression analysis was used to investigate the influencing factors for the progression of liver fibrosis. ResultsA total of 307 patients were enrolled， with a mean age of 50.0 years， and the male patients accounted for 80.5%. After 48 weeks of treatment with the adjusted NAs regimen， 254 patients （82.7%） achieved CVR， and 53 patients （17.3%） still had LLV. For the LLV group， the incidence rate of PLC was 30.2% and the rate of liver fibrosis progression was 22.6%， while for the CVR group， the incidence rate of PLC was only 13.4%， and the rate of liver fibrosis progression was 7.5%. The multivariate regression analyses showed that LLV was an independent risk factor for the onset of PLC （hazard ratio=2.623， 95% confidence interval ［CI］： 1.315‍ ‍—‍ ‍5.234， P=0.006） and the progression of liver fibrosis （odds ratio=3.213， 95%CI： 1.385‍ ‍—‍ ‍7.455， P=0.007）. ConclusionActive adjustment of treatment is needed immediately after the diagnosis of LLV to improve CVR， and if LLV persists after treatment adjustment， it is necessary to enhance the monitoring of liver fibrosis progression and PLC， so as to facilitate early diagnosis and treatment.

Objective:To investigate the current status of occupational stress among electronic manufacturing workers in Qingdao and analyze its effect on depressive symptoms and anxiety symptoms.Methods:From July to September 2022, a cluster random sampling method was employed to select frontline workers from 14 electronic manufacturing enterprises in Qingdao as the study subjects. A total of 1134 questionnaires were distributed, with 1000 valid questionnaires collected, yielding an effective response rate of 88.18%. The Core Occupational Stress Scale (COSS), the Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder-7 (GAD-7) were adopted to assess occupational stress, depressive symptoms, and anxiety symptoms, respectively. Binary logistic regression was employed to analyze influencing factors of occupational stress and its effects on depressive and anxiety symptoms.Results:The detection rates of occupational stress, depressive symptoms, and anxiety symptoms were 15.1% (15/1000), 7.9% (79/1000), and 13.8% (138/1000), respectively. The influencing factor analysis of occupational stress revealed that female gender ( OR=0.621, 95% CI: 0.434-0.890) and weekly working hours of 45-48 hours ( OR=0.537, 95% CI: 0.309-0.935) were protective factors ( P<0.05), while weekly working hours ≥55 hours ( OR=2.176, 95% CI: 1.290-3.670) and shift work ( OR=2.038, 95% CI: 1.412-2.940) were risk factors ( P<0.05). Spearman correlation analysis showed that the COSS score was positively related with the PHQ-9 score and the GAD-7 score ( rs=0.438, 0.289, P<0.01). Workers judged with occupational stress had 3.596 times (95% CI: 2.181-5.931, P<0.001) and 3.121 times (95% CI: 2.046-4.761, P<0.001) higher risks of detecting depressive and anxiety symptoms compared to those without occupational stress. Conclusion:Electronic manufacturing workers in Qingdao experience a certain level of occupational stress, which may increase the risk of developing depressive and anxiety symptoms. Enterprises should implement appropriate interventions to promote workers' mental health.

Objective To explore the physical function indicators of elderly women with fall experiences,so as to provide more data reference for fall prevention,risk assessment,and solving of aging-related health problems in elderly women.Methods The fall history of 167 elderly women in communities in Tianjin was investigated by a questionnaire.The participants were assigned into a fall group(more than 2 falls in the last 1 year)and a non-fall group according to the number of falls.Body composition was tested by an Inbody 770 Body Composition Analyzer,and the calcaneus bone mineral density was measured by a UBD2002A Ultrasound Bone Densitometer.The muscle strength and proprioception of knee and ankle joints of lower limbs were measured by a PRIMUS BTE Isokinetic Tester.The muscle strength of lower limbs was evaluated by the number of 30-second sitting-rising.The visual sensitivity was examined by two-contrast near point reading cards(with a small number of strokes).The dynamic and static balance abilities were determined by a Korebalance Tester,and the static balance ability was tested by one-leg standing with eyes closed.The dynamic and static balance was assessed based on the Berg balance scale,and walking gait characteristics were studied by a BTS three-dimensional motion capture system.Results The skeletal muscle content(P<0.001),strength of non-dominant knee flexor muscle(P=0.002),number of 30-second sitting-rising(P=0.006),and average walking speed(P=0.013)in the fall group were lower than those in the non-fall group.The visual acuity at 10% grayscale(P=0.001),active knee joint position sense(P<0.001),strength of non-dominant ankle flexor muscle(P<0.001),and one-leg standing time with eyes closed(P<0.001)in the fall group were lower than those in the non-fall group.The fall group outperformed the non-fall group in right-left balance rate(P=0.031)and forward-backward balance rate(P=0.028)during static and dynamic balance tests.Conclusion The ankle angle,proprioception,muscle strength,and skeletal muscle content of lower limbs,visual sensitivity,dynamic and static balance abilities,and walking ability of elderly women with fall experiences were lower than those without fall experiences.
Humans ; Accidental Falls ; Aged ; Female ; Postural Balance ; Muscle Strength ; Body Composition ; Bone Density ; Surveys and Questionnaires ; Gait

ObjectiveTo investigate the features of liver histopathological damage in patients with indeterminate phase of chronic HBV infection， as well as the timing for initiating antiviral therapy in such patients. MethodsA retrospective screening was performed for the patients with chronic HBV infection who were hospitalized in The Fifth Medical Center of Chinese PLA General Hospital and underwent liver biopsy from March 2018 to April 2022， among whom the patients who met the criteria for indeterminate phase defined in Chinese guidelines for chronic hepatitis B prevention and treatment （2022 edition） were enrolled， and their clinical data were collected. Liver histopathological stage was determined using the Scheuer scoring system， with stages 0 — 4 for inflammation grade （G） and stages 0 — 4 for fibrosis degree （S）， and the patients were divided into groups based on the presence of significant necroinflammation （≥G2） and significant liver fibrosis （≥S2）. The independent samples t-test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. A Spearman’s rank correlation analysis was used to investigate the correlation between liver histopathology and clinical factors， and the Logistic regression model was used to identify the independent influencing factors for significant necroinflammation and liver fibrosis. ResultsA total of 271 patients with indeterminate phase of chronic HBV infection were enrolled， among whom 61 （22.5%） had significant necroinflammation （≥G2） and 124 （45.8%） had significant liver fibrosis （≥S2）. The Logistic regression analysis showed that alanine aminotransferase ≥30 U/L （for male patients） or ≥19 U/L （for female patients） （odds ratio ［OR］=2.69， 95% confidence interval ［CI］： 1.39 — 5.21， P=0.003）， HBV DNA ≥2 000 IU/mL （OR=2.75， 95%CI： 1.38 — 5.48， P=0.004）， and liver stiffness measurement （LSM） ≥6.0 kPa （OR=4.57， 95%CI： 2.17 — 9.62， P<0.001） were independent risk factors for significant inflammation. HBV DNA ≥2 000 IU/mL （OR=1.82， 95%CI： 1.01 — 3.32， P=0.049） and LSM ≥6.0 kPa （OR=2.06， 95%CI： 1.23 — 3.43， P=0.006） were independent influencing factors for significant liver fibrosis. ConclusionAmong the patients with indeterminate phase of chronic HBV infection， a substantial proportion of patients have significant liver histopathological damage. Antiviral therapy should be initiated in a timely manner for patients with high-risk factors.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.