Objective To investigate the infection status and changing trend of hepatitis C virus(HCV)infection in hospitalized patients in medical institutions,and provide reference for formulating HCV infection prevention and control strategies.Methods HCV infection surveillance results from cross-sectional survey data reported to China Healthcare-associated Infection(HAI)Surveillance System in 2020 were summarized and analyzed,HCV positive was serum anti-HCV positive or HCV RNA positive,survey result was compared with the survey results from 2003.Results In 2020,1 071 368 inpatients in 1 573 hospitals were surveyed,738 535 of whom underwent HCV test,4 014 patients were infected with HCV,with a detection rate of 68.93％and a HCV positive rate of 0.54％.The positive rate of HCV in male and female patients were 0.60％and 0.48％,respectively,with a statistically sig-nificant difference(x2=47.18,P＜0.001).The HCV positive rate in the 50-＜60 age group was the highest(0.76％),followed by the 40-＜50 age group(0.71％).Difference among all age groups was statistically signifi-cant(x2=696.74,P＜0.001).In 2003,91 113 inpatients were surveyed.35 145 of whom underwent HCV test,resulting in a detection rate of 38.57％;775 patients were infected with HCV,with a positive rate of 2.21％.In 2020,HCV positive rates in hospitals of different scales were 0.46％-0.63％,with the highest in hospital with bed numbers ranging 600-899.Patients'HCV positive rates in hospitals of different scales was statistically signifi-cant(X2=35.34,P＜0.001).In 2020,12 provinces/municipalities had over 10 000 patients underwent HCV-rela-ted test,and HCV positive rates ranged 0.19％-0.81％,with the highest rate from Hainan Province.HCV posi-tive rates in different departments were 0.06％-0.82％,with the lowest positive rate in the department of pedia-trics and the highest in the department of internal medicine.In 2003 and 2020,HCV positive rates in the depart-ment of infectious diseases were the highest,being 7.95％and 3.48％,respectively.Followed by departments of orthopedics(7.72％),gastroenterology(3.77％),nephrology(3.57％)and general intensive care unit(ICU,3.10％)in 2003,as well as departments of gastroenterology(1.35％),nephrology(1.18％),endocrinology(0.91％),and general intensive care unit(ICU,0.79％)in 2020.Conclusion Compared with 2003,HCV positive rate decreased significantly in 2020.HCV infected patients were mainly from the department of infectious diseases,followed by departments of gastroenterology,nephrology and general ICU.HCV infection positive rate varies with gender,age,and region.

Objective To explore the value of droplet digital polymerase chain reaction(ddPCR)in the etiological diagnosis of severe acute pancreatitis(SAP)patients with suspected bloodstream infection(BSI).Methods SAP patients admitted to the department of critical care medicine in a hospital July to September 2022 were enrolled.When BSI was suspected,venous blood was collected for both ddPCR detection and blood culture(BC)with antimi-crobial susceptibility testing(AST)simultaneously.The time required for two detection methods was recorded,and the detection results of ddPCR and BC were compared.The etiological diagnostic efficacy of ddPCR was calculated,and the correlation between the value of pathogen load detected by ddPCR and the level of infection parameters was explored.Results A total of 22 patients were included in the analysis,and 52 venous blood specimens were collec-ted for detection.BC revealed 17 positive specimens(32.7％)and 29 pathogenic strains,while ddPCR showed 41 positive specimens(78.8％)and 73 pathogenic strains.Detection time required for ddPCR was significantly lower than that of BC([0.16±0.03]days vs[5.92±1.20]days,P＜0.001).Within the detection range of ddPCR and taking BC results as the gold standard,the sensitivity and specificity of ddPCR were 80.0％and 28.6％,respective-ly.With the combined assessment of BSI based on non-blood specimen microbial evidence within a week,the sensi-tivity and specificity of ddPCR detection increased to 91.9％and 76.9％,respectively.ddPCR detected resistance genes of blaKPC,blaNDM/IMP,VanA/VanM,and mecA from 19,9,6,and 5 specimens,respectively.Correlation analysis showed a positive correlation between pathogen load and levels of C-reactive protein as well as procalcitonin(r=0.347,0.414,P＜0.05).Conclusion As a supplementary detection method for BC in BSI diagnosis,ddPCR has the advantages of higher sensitivity and shorter detection time,and is worthy of further exploration in clinical application.

Objective To compare the differences in virulence-related factor aspartate protease,biofilm formation,and gene expression among clinical isolates of Candida parapsilosis(C.parapsilosis).Methods Gene sequencing and microsatellite typing(MT)method were adopted to identify C.parapsilosis isolated from patients with clinical fungal infection.The production of secreted aspartate protease and biofilm formation ability of each strain were de-tected,and the expression of biofilm formation related-genes BCR1,EFG1,and HWP1,as well as aspartate prote-ase virulence genes SAPP1,SAPP2,SAPP3 were compared among the strains.Results A total of 8 clinically iso-lated C.parapsilosis strains were collected,all of which were identified as genotype Ⅰ.Based on microsatellite ty-ping results,8 clinical strains were divided into 4 microsatellite types.G1,G2,and G3 strains isolated from the urine,peripherally inserted central catheters(PICC),and blood of patient A were of different subtypes.J1,J2,J3,J4,and J5 strains were of the same type,and isolated from blood specimens of patient B at different periods.All 8 clinical strains could form biofilm,and their biofilm formation ability was higher than that of the standard strain of C.parapsilosis(ATCC 22019).G1,G3 and J5 strains had strong biofilm formation ability,J1,J2,J3,and J4 strains had moderate biofilm formation ability,and G2 strain had weak biofilm formation ability.All of the eight clinical isolates secreted aspartate protease,and their in vitro expression levels of the enzyme were higher than that of the standard strain(ATCC 22019).G3,G1,and G2 strains showed low,moderate,and high in vitro enzyme expression respectively,with statistical differences(all P＜0.05).Enzyme expressed moderately in J1 and J5 strains,and highly in J2,J3,and J4 strains.Difference between moderate and high expressions was statistically significant(P＜0.05).The expression levels of biofilm formation genes BCR1,EFG1,and HWP1 in various strains isolated from patients A and B increased.In strains isolated from patient A,the expression level of EFG1 gene in G1 strain was higher than that in G2 strain(P＜0.05).There was no statistically significant difference in BCR1,EFG1,and HWP1 gene expression levels among strains isolated from patient B.The expression levels of as-partate protein genes(SAPP1,SAPP2,and SAPP3)in various strains isolated from patients A and B increased.The expression levels of SAPP1 and SAPP2 in strain G1 were higher than those in G2 and G3(both P＜0.05).There was no statistically significant difference in the expression levels of SAPP1,SAPP2,and SAPP3 genes in strains from patient B.Conclusion Clinical isolates of C.parapsilosis have higher biofilm formation and aspartate protease production abilities than standard strain.The expression of virulence factors varies among strains isolated from different specimens,while there is no significant difference in the expression of virulence factors among strains isolated at different periods.Patients may have been infected with different MT types of C.parapsilosis in multiple sites during the same period.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Objective To evaluate the efficacy of vitamin C intravenous injection in the treatment of patients with sepsis.Methods PubMed,Embase,Scopus,Cochrane Library,and Clinical Trial databases were retrieved,with a retrieval period from database establishment to December 2022.English literatures on randomized controlled trial(RCT)of vitamin C intravenous injection for the treatment of sepsis or septic shock were collected.Meta-analysis was conducted using RevMan 5.3 software and Stata 15.0 software after literature screening,extraction,and evalua-tion of the bias risk included in the studies by two researchers independently.Results A total of 16 RCT studies involving 3 301 patients were included in the analysis.In terms of main outcomes,the 28-day mortality of patients in the vitamin C treatment group was slightly lower than that of the control group,but the difference was not statis-tically significant(RR=0.86,95％CI[0.72-1.03],P=0.10;I2=44％,P=0.10).In terms of secondary out-comes,vitamin C intravenous injection can reduce the duration of vasoactive drug usage time(MD=-23.44,95％CI[-30.53--16.35],P＜0.01;I2=0,P=0.97),but has no significant effect on the 90-day mortality,inten-sive care unit mortality,hospital mortality,duration of mechanical ventilation,difference in estimated sequential organ failure assessment score at 72 hour,length of stay in ICU,and total length of hospital stay of patients(P＞0.05).Conclusion Intravenous vitamin C injection can significantly reduce vasoactive drug usage time,but the available evidence is insufficient to support that intravenous vitamin C can improve the prognosis of patients with sepsis or septic shock.More high-quality,multicenter randomized controlled trial is needed to provide more substantial evidence about the efficacy of vitamin C in treating sepsis or septic shock.

Objective To investigate the attributable risk(AR)of Acinetobacter baumannii(AB)infection in criti-cally ill patients.Methods A multicenter retrospective cohort study was conducted among adult patients in inten-sive care unit(ICU).Patients with AB isolated from sterile body fluid and confirmed with AB infection in each cen-ter were selected as the infected group.According to the matching criteria that patients should be from the same pe-riod,in the same ICU,as well as with similar APACHE Ⅱ score(±5 points)and primary diagnosis,patients who did not infect with AB were selected as the non-infected group in a 1:2 ratio.The AR was calculated.Results The in-hospital mortality of patients with AB infection in sterile body fluid was 33.3％,and that of non-infected group was 23.1％,with no statistically significant difference between the two groups(P=0.069).The AR was 10.2％(95％CI:-2.3％-22.8％).There is no statistically significant difference in mortality between non-infected pa-tients and infected patients from whose blood,cerebrospinal fluid and other specimen sources AB were isolated(P＞0.05).After infected with AB,critically ill patients with the major diagnosis of pulmonary infection had the high-est AR.There was no statistically significant difference in mortality between patients in the infected and non-infec-ted groups(P＞0.05),or between other diagnostic classifications.Conclusion The prognosis of AB infection in critically ill patients is highly overestimated,but active healthcare-associated infection control for AB in the ICU should still be carried out.

Objective To explore the antimicrobial resistance of carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from blood and the related risk factors for infection in patients.Methods Clinical data of 383 KP-infected patients from whose blood Klebsiella pneumoniae(KP)were isolated during hospitalization period in a hos-pital from January 2018 to December 2021 were retrospectively analyzed.Patients were divided into CRKP group(n=114)and non-CRKP group(n=269)based on antimicrobial resistance.According to the prognosis,114 patients in the CRKP group were subdivided into the death group(n=30)and the survival group(n=84).General informa-tion,underlying diseases,antimicrobial use,and infection outcomes of two groups of patients were compared,and risk factors for infection and death after infection were analyzed.Results The resistance rates of KP to tigecycline and compound sulfamethoxazole showed upward trends,with statistically significant differences(both P=0.008).The CRKP group had higher resistance rates to amikacin,aztreonam,compound sulfamethoxazole,ciprofloxacin,cefepime,cefoperazone/sulbactam,piperacillin/tazobactam,tigecycline,ceftazidime,tobramycin,and levofloxacin,as well as higher in-hospital mortality than the non-CRKP group,with statistically significant differences(all P＜0.05).Acute pancreatitis prior to infection(OR=16.564,P＜0.001),hypoalbuminemia(OR=8.588,P＜0.001),stay in in-tensive care unit prior to infection(OR=2.733,P=0.017),blood transfusion(OR=3.968,P=0.001),broncho-scopy(OR=5.194,P=0.014),surgery within 30 days prior to infection(OR=2.603,P=0.010),and treatment with carbapenems(OR=2.663,P=0.011)were independent risk factors for the development of CRKP blood-stream infection(BSI).Cardiac insufficiency before infection(OR=11.094,P=0.001),combined with pulmonary infection(OR=20.801,P=0.010),septic shock(OR=9.783,P=0.002),disturbance of consciousness(OR=11.648,P=0.001),and receiving glucocorticoid treatment(OR=5.333,P=0.018)were independent risk factors for mortality in patients with CRKP BSI.Conclusion The resistance rate of KP from BSI to tigecycline and com-pound sulfamethoxazole presents upward trend.Underlying diseases,invasive procedures,and carbapenem treat-ment are closely related to CRKP BSI.Cardiac insufficiency,pulmonary infection,septic shock,disturbance of con-sciousness,and glucocorticoid treatment can lead to death of patients with CRKP BSI.

Objective To understand the infection status of patients with maintenance hemodialysis(MHD)in Guizhou Province,and provide basis for the prevention and control of hemodialysis-related infection.Methods MHD patients in hemodialysis centers of 124 secondary and or higher grade medical institutions in Guizhou Province from July to December 2022 were surveyed.Survey content included the general conditions of patients,hemodialysis-related conditions,infection of pathogens of blood-borne diseases,and other infection-related conditions.Results A total of 15 114 MHD patients were surveyed,with age mainly ranging from 36 to＜60 years old(55.83％).Hemodialysis history ranged mainly from 1 year to＜5 years(59.37％),and the frequency of hemodi-alysis was mainly 3 times per week(73.91％).Autologous arteriovenous fistula(AVF)was the major vascular access for dialysis,with a total of 12 948 cases(85.77％).The main primary disease was chronic renal failure(99.89％).The infection rates of hepatitis B virus(HBV),hepatitis C virus(HCV),human immunodeficiency vi-rus(HIV),and Treponema pallidum in MHD patients were 5.29％,0.64％,0.24％,and 1.70％,respectively.HBV infection rates among MHD patients of different ages,different numbers of dialysis hospitals,and dialysis in-stitutions of different scales showed statistically significant differences(all P＜0.05).HCV infection rates among MHD patients of different ages,with different dialysis times and from institutions of different scales were signifi-cantly different(all P＜0.05).TP infection rates among MHD patients of different ages and different numbers of dialysis hospitals were all significantly different(all P＜0.05).Infection rates of HBV and HCV in MHD patients aged from 36 to 60 years old(not included)were relatively higher(6.10％and 0.84％,respectively).Patients with dialysis time ≥10 years had a higher HCV infection rate(1.64％).Infection rates of HCV,HIV,and TP in pa-tients dialyzed in medical institutions with ≥90 dialysis beds were relatively higher(0.74％,0.28％,and 1.94％,respectively).Medical institutions with＜30 dialysis beds had the highest HBV infection rate(18.64％).There were 9 cases(0.06％)of vascular puncture infection,12 cases(0.08％)of bloodstream infection,7 cases(0.05％)of vascular access-related bloodstream infection,and 30 cases(0.20％)of pulmonary infection.Vascular access-re-lated bloodstream infection rate and pulmonary infection rate among MHD patients with different types of vascular access showed statistically significant difference(all P＜0.05).Vascular access-related bloodstream infection rate(0.37％)and pulmonary infection rate(1.10％)of patients with non-cuffed catheters vascular access were higher than those of other types.Conclusion MHD patients in Guizhou Province are mainly middle-aged and young peo-ple,with more males than females.The dialysis frequency is mostly 3 times per week,and AVF is the major vascu-lar access.MHD patients are prone to complications such as infections of HBV,HCV,HIV,and TP,as well as bloodstream infection and pulmonary infection.

Objective To understand the changing trend of healthcare-associated infection(HAI)monitoring inde-xes in 50 secondary and higher grade hospitals in a city for 6 consecutive years from 2017 to 2022.Methods Infec-tion monitoring indexes from 50 secondary or higher grade hospitals in the city for 6 consecutive years were collec-ted,and changing trend of HAI monitoring indexes were compared.Results The number of full-time HAI manage-ment professionals increased from 91 in 2017 to 165 in 2022.The utilization rate of HAI information system in-creased from 17.00％in 2017 to 54.00％in 2022.In 6 consecutive years from 2017 to 2022,the incidence of HAI(0.91％vs 0.59％),prevalence rate of HAI(2.36％vs 1.08％),infection rate of class I incision surgical site in-fection(0.33％vs 0.16％)in 50 secondary or higher grade hospitals all showed downward trends,while health care workers'hand hygiene compliance rate showed an upward trend(61.03％vs 85.04％).Incidences of vascular cathe-ter-related bloodstream infection,ventilator-associated pneumonia,and catheter-associated urinary tract infection all showed downward trends.Incidence of HAI,prevalence rate of HAI,health care workers'hand hygiene compli-ance rate,and incidence of ventilator-associated pneumonia in tertiary hospitals were all higher than those in secon-dary hospitals,while surgical site infection rate of class Ⅰ incision in secondary hospitals was higher than that in tertiary hospitals,with statistically significant differences(all P＜0.001).Conclusion Standardizing the monitoring of HAI,as well as improving the prevention and control system and measures of HAI according to the monitoring results can reduce the incidence of HAI.

Objective To investigate the microbial contamination and management of refrigerators in the ward treatment rooms of a tertiary first-class hospital,and provide reference for strengthening the cleaning and disinfec-tion of medical refrigerators in the ward treatment rooms.Methods A total of 40 refrigerators in use from the treatment rooms of different wards in the hospital were randomly selected for microbial sampling,culture,and bac-terial identification.Forty nurses were randomly chosen from the corresponding wards for a questionnaire survey on the daily management of refrigerators.Results A total of 223 specimens were collected,with 142 microbial positive specimens and a positive rate of 63.68％.A total of 247 bacterial strains were detected,including 41.30％(n=102)Gram-positive bacteria,10.93％(n=27)Gram-negative bacteria,and 47.77％(n=118)fungi.Two strains of multidrug-resistant Pseudomonas aeruginosa from the bottom and drainage tank of the same refrigerator from class-Ⅲ environment were detected,with a detection of multidrug-resistant organisms being 0.90％(2/223).The fre-quency and methods of routine cleaning and disinfection of refrigerators varied among different wards.Conclusion There are deficiencies in the cleaning and disinfection management of refrigerators in ward treatment rooms of medi-cal institutions.More attention should be paid to the cleaning and disinfection of refrigerators in wards.The health-care-associated infection management departments should strengthen corresponding supervision and management.