Abstract:On December 7, 2022, the Notice on Further Optimizing the Implementation of COVID- 19 Prevention and Control Measures (referred to as "Ten new guidelines") proposed that all levels of medical institutions should ensure normal medical services and provide medical convenience for special patients. As the main force of medical treatment and control of epidemic spread, health care workers (HCWs) are at high risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. After HCWs are infected with SARS-CoV-2, correct treatment and isolation measures can fundamentally ensure their healthy and safety, which is also a strong guarantee for the treatment of patients. After soliciting relevant experts' opinions, according to current epidemic situation and virus mutation of COVID-19, on the basis of referring national documents, guidelines and authoritative literatures, as well as in combination with practical experience in COVID-19 epidemic prevention and control management, the National Healthcare-associated Infection Monitoring and Management Training Center as well as Editorial Board of Chinese Journal of Infection Control proposed suggestions and corresponding specific measures for COVID-19 infection management, home treatment and return to work of HCWs, for the reference of relevant medical institutions and HCWs.

Abstract:In view of the high incidence, high drug resistance, high transmission and high mortality of infection in critically ill patients in intensive care unit (ICU), how to conduct scientific prevention and control as well as treatment for drug-resistant bacterial infection has become the focus of global public health and major clinical problem that needs to be solved. Effective prevention of cross transmission and infection of drug-resistant bacteria at common sites of ICU patients is crucial. Focusing on the key issues of infection prevention and control, the standardized infection prevention and control mode for drug-resistant bacteria in ICU was formed through the implementation of key prevention and control measures, including active screening, quarantine, disinfection, patient transport, compliance assessment, etc., so as to effectively reduce the incidence of carbapenem-resistant Gram-negative organism colonization/infection in critically ill patients.

Abstract:Objective To construct a grey prediction model based on bacterial drug resistance data of methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Pseudomonas aeruginosa (CRPA), carbapenem-resistant Acinetobacter baumannii (CRAB), third-generation cephalosporin-resistant Escherichia coli (3GCR-E. coli), and third-generation cephalosporin-resistant Klebsiella pneumoniae (3GCR-KP), analyze the trends in bacterial drug resistance characteristics, and explore the application value of grey prediction model in the field of bacterial drug resistance. Methods A grey prediction model GM(1, 1) was constructed based on drug resistance rate data of MRSA, CRPA, CRAB, 3GCR-E. coli, and 3GCR-KP from the national bacterial drug resistance surveillance reports in 2014-2018. The precision of the model was assessed with posterior error ratio (C) and the small error probability (P). The fitting effectiveness of the model was evaluated with relative error and grade ratio deviation. The prediction effectiveness of the model was verified with the data from 2019 to 2020. Final prediction of drug resistance rates from 2021 to 2023 was made based on the constructed model. Results The GM (1, 1) model constructed in this study has good prediction effectiveness on drug resistance rates of MRSA, CRPA, CRAB, 3GCR-E. coli and 3GCR-KP. According to this model, resistance rates of the above bacteria were predicted to be reduced to 23.9%, 15.2%, 50.2%, 43.8%, and 26.1% respectively by 2023. Conclusion The control measures taken against bacterial drug resistance in China have achieved remarkable results. GM (1, 1) model is effective in predicting bacterial drug resistance rate and can be promoted for the application in the field of bacterial drug resistance management.

Abstract:Objective To understand the outbreak of healthcare-associated infection (HAI) caused by Pseudomonas aeruginosa (P. aeruginosa) and provide reference for targeted prevention and control of the outbreak. Methods P. aeruginosa HAI outbreak events from January 1, 2005 to July 18, 2022 were retrieved from Worldwide Database for Nosocomial Outbreaks and PubMed. The surveyed contents and relevant data were collected in Excel and analyzed. Risk factors for the acquisition and transmission of P. aeruginosa in case-control and cohort studies were evaluated systematically with Meta-analysis. Results From January 1, 2005 to July 18, 2022, 149 HAI outbreaks of P. aeruginosa occurred in 27 countries. Sources of 78 outbreaks were identified, mainly hospital water system (35.90%) and medical equipments (43.59%). P. aeruginosa was mostly transmitted through contaminated medical equipments (34.82%) and water system (32.14%), followed by contaminated hands (16.96%) and environmental object surfaces (16.07%). By taking specific measures to different outbreak sources and strengthening the implementation of basic measures, 79.8% P. aeruginosa HAI outbreaks terminated. Pulsed-field gel electrophoresis, polymerase chain reaction and whole genome sequencing were the most widely used molecular typing methods in outbreak investigation (adopted 86, 21 and 8 times respectively). Meta-analysis results of 15 case-con trol studies showed that length of hospital stay (OR=30.87, 95%CI: 11.89-80.16), carbapenem-resistant antibiotics (OR=7.95, 95%CI: 3.25-19.45) and utilization of medical equipments (OR=6.07, 95%CI: 1.79-23.49) were the main risk factors for P. aeruginosa acquisition and transmission. Conclusion According to the epidemic characteristics and risk factors of the P. aeruginosa outbreak, it is important to focus on monitoring and detecting the contamination of water system and medical equipments in the early stage, and formulate specific intervention measures, thus effectively prevent and control the outbreak of P. aeruginosa infection.

Abstract:Objective To study the homologous relationship between the carbapenem-resistant Klebsiella pneumoniae (CRKP) in burn patients and the environmental bacterial strains, and provide scientific basis for the prevention and treatment of CRKP infection in burn patients. Methods Patients with CRKP infection from June to December 2020 in burn intensive care unit of a hospital were prospectively monitored. Clinical and environmental specimens were collected. Strains were identified and tested for antimicrobial susceptibility through Compact VITEK 2 automatic microbial analyzer. Homology of the strains were analyzed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Carrying Status of virulence genes and capsular serotype genes were detected. Results A total of 4 burn patients developed CRKP infection, 2 strains were isolated from wound secretion and 2 from blood. 152 environmental specimens were collected, 15 CRKP strains were obtained after bacterial identification and antimicrobial susceptibility test. Cluster analysis through PFGE showed 7 cluster groups A-G. Blood specimens of patient 1, blood and environmental specimens of patient 2, as well as wound secretion and environmental specimens of patient 3 were homologous(all type A). Type A-G strains were analyzed by MLST, and showed that type A-G were ST11, ST35, ST1, ST37, ST2929, ST23, and ST17. Virulence genes of 15 CRKP strains were tested, out of which 5 strains were K57, with ST types of ST35, ST37 and ST17. Conclusion Detection rate of CRKP in the environment of burn patients is high. Strains isolated from environmental specimens were found homologous to that from clinical specimens, indicating that effective control of environmental contamination is conducive to the prevention and control of infection spread. In addition, CRKP exhibits prevalence of clone strains, which may combine with high virulence. More extensive monitoring should be carried out.

Abstract:Objective To understand the drug resistance, virulence and epidemiological characteristics of clinically isolated carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP). Methods Clinically isolated carbapenem-resistant Klebsiella pneumoniae (CRKP) from a teaching hospital in Anhui Province from January 2018 to December 2020 were collected, their clinical characteristics were analyzed. Bacterial trains were identified by time-of-flight mass spectrometry, CR-hvKP was screened out by string test and virulence gene detection, carbapenem-resistant non-hypervirulent Klebsiella pneumoniae (CR-non-hvKP)isolated in the same ward or at a similar time with CR-hvKP was as control group according to 1:1 ratio. The whole genome sequencing was used to analyze the capsule serotype, drug resistance, virulence gene and ST typing of CR-hvKP and CR-non-hvKP in control group, difference between two groups of strains was compared. Results A total of 512 CRKP strains were isolated, including 30 CR-hvKP strains and 482 CR-non-hvKP strains. Most patients with CR-hvKP infection were the elderly (n=20, 66.67%), with respiratory diseases (n=29, 96.67%), digestive system diseases (n=12, 40.00%), septic shock (n=10, 33.33%), invasive treatment (n=23, 76.67%) and high mortality (n=20, 66.67%). Resistant rates of CR-hvKP to most commonly used antimicrobial agents were>90%, to tegacyclin was 3.33%, and all were sensitive to polymyxin B. There was no statistically significant difference in resistance between CR-hvKP and CR-non-hvKP (P>0.05). Sequencing results showed that the major carbapenem-resistance gene carried by CR-hvKP was bla_KPC-2 (n=28, 93.33%). Detection rate of resistant genes SHV-11, mph(A) and armA were lower than those of CR-non-hvKP strains. Detection rates of virulence genes iucA, iutA, fimF, fimH and mrkD carried by 30 CR-hvKP strains were all 100%, which was higher than those of CR-non-hvKP strains, with statistically significant difference (all P < 0.05). Detection rate of ST11-K64 in CR-hvKP strains was higher than that in CR-non-hvKP strains (76.67% vs 40.00%, P < 0.05). Conclusion KPC-2-producing ST11-K64 CR-hvKP is the main prevalent strain in the hospital, which carries more virulence and drug resistance genes and has a high mortality. The elderly and intensive care unit patients should be paid more attention in clinic.

Abstract:Objective To investigate the clinical distribution, drug resistance and clonal transmission of Haemophilus influenzae (H. influenzae) isolated from children with pneumonia in Haikou City, and provide a theoretical basis for the prevention and treatment of H. influenzae pneumonia in children. Methods Clinical data of 5 342 hospitalized children with pneumonia in Haikou Hospital of the Maternal and Child Health in 2021 were collected. Positive rate of H. influenzae from children's respiratory tract specimens was calculated, and drug resistance and homology of multilocus sequence typing (MLST) of strains were analyzed. Results 352 H. influenzae strains were isolated from 5 342 children with pneumonia, with an isolation rate of 6.59%. Isolation rates of H. influenzae of male and female children were 7.10% and 5.82% respectively; isolation rates of H. influenzae of children at the age of < 30 days, 30 days-, 2 years-, 4 years-, and ≥ 6 years were 0.30%, 8.45%, 11.62%, 12.88% and 2.56% respectively, with a statistically significant difference among all age groups(P < 0.05). Isolation rates in spring, summer, autumn, and winter were 14.04%, 4.48%, 4.62%, and 4.40% respectively, seasonal difference was statistically significant (P < 0.001). Positive rate of H. influenzae β-lactamase was 42.60% (141/331). Resistance rates of H. influenzae to compound sulfamethoxazole, ampicillin, and cefuroxime were 76.43%, 69.19%, and 51.36% respectively, to azithromycin, amoxicillin/clavulanic acid, ceftazidime, and ceftriaxone were all < 30%, to meropenem and levofloxacin were < 1%. 51 H. influenzae strains were divided into 15 ST types by MLST sequencing, including 11 strains (21.57%) of ST107, which mainly distributed among children aged 4 months-1 year (9 strains) and 3 years (2 strains). Conclusion H. influenzae isolated from children with pneumonia in Haikou City is genetically diverse and transmitted through community cloning. Most children with pneumonia were aged 2-3 years old. Spring is the peak season of high infection incidence. ST107 is dominant in spring. Empiric treatment with compound sulfamethoxazole, ampicillin and cefuroxime should be cautious. Resistance to amoxicillin/clavulanic acid and resistance of β-lactamase negative strains to ampicillin increased, which should be paid attention in clinic.

Abstract:Objective To explore the application of autoregressive integrated moving average (ARIMA) model in the prediction of carbapenem-resistant Klebsiella pneumoniae (CRKP) healthcare-associated infection (HAI). Methods The monthly incidence of CRKP HAI in a hospital from January 2018 to June 2022 was selected. ARIMA model was established by SPSS19.0, and the fitting of the model were analyzed. CRKP HAI data from July 2021 to June 2022 was used to verify the model and evaluate its predictive value. Results Monthly CRKP HAI incidence of hospitalized patients from January 2018 to June 2022 was used to establish the model and conduct fitting process, finally acquired the optimal model ARIMA (0, 1, 9). With an average relative error of 7.76%, the model-predicted value for CRKP HAI incidence was consistent with the actual value, thus fitting well with actual data. Conclusion ARIMA model can effectively fit and predict the incidence of CRKP HAI, and provide scientific guidance for CRKP HAI prevention and control.

Abstract:Objective To explore the distribution characteristics and drug resistance of pathogens in patients with acquired immunodeficiency syndrome (AIDS). Methods Clinical data of AIDS patients in a hospital from 2017 to 2021 were collected retrospectively, distribution and drug resistance of infectious pathogens as well as distributional difference between healthcare-associated infection (HAI) and community-associated infection (CAI) were analyzed. Results A total of 1 711 pathogenic strains were isolated from 3 677 AIDS patients, out of which CAI-, HAI- and colonized strain numbers were 1 523, 77, and 111. Pathogenic constituents of 3 groups were significantly different (P < 0.001), with Fungi as the major pathogens, accounting for 64.35%, 36.36%, and 50.45% respectively. Respiratory tract infection (RTI) was the major CAI (40.97%), and bloodstream infection (BSI) was the major HAI (28.57%), with a statistically significant difference in the constituent ratio of infection sites between CAI and HAI (P < 0.001). In RTI, BSI and urinary tract infection of AIDS patients, difference in constituent ratio of pathogens between CAI and HAI was statistically different (P < 0.05).Isolation rate of multidrug-resistant organisms among different strains was statistically different (P < 0.001). Isolation rate was the highest in methicillin-resistant Staphy-lococcus epidermidis (58.33%), followed by carbapenem-resistant Acinetobacter baumannii (44.44%), methicillin-resistant Staphylococcus haemolyticus (33.33%) and methicillin-resistant Staphylococcus aureus (33.33%). Conclusion There are obvious differences in the pathogenic constitutions in CAI, HAI and colonization of AIDS patients, as well as in the distribution of infection sites between HAI and CAI. Detection rates of multidrug-resistant organisms of different strains are varied, resistance rate to commonly used antimicrobial agents is high. To prevent the spread of MDROs in community, emphasis should be put on monitoring the dynamics of pathogen drug resis-tance in AIDS patients and rational usage of antimicrobial agents.

Abstract:Objective To understand the serotype distribution and drug resistance genes of Streptococcus agalactis (group B streptococcus, GBS) isolated from the reproductive tract of pregnant women, and provide reference for the clinical prevention and treatment of GBS infection and rational use of antimicrobial agents. Methods Hospitalized women in late pregnancy with GBS detected in reproductive tract secretion from January 2020 to June 2021 were selected as research objects. Genotypes and drug resistance genes of isolated and cultured GBS were analyzed by polymerase chain reaction (PCR) and gene sequencing. Results A total of 62 GBS strains were isolated, serotypes of which were types Ⅲ (n=30, 48.4%), Ⅰa (n=16, 25.8%), Ⅰb (n=8, 12.9%), Ⅴ (n=6, 9.7%), and Ⅵ (n=2, 3.2%) respectively. GBS drug susceptibility test showed high resistance to tetracycline, erythromycin and clindamycin, with drug resistance rates of 77.4%, 71.0% and 67.7% respectively. There was no resistance to ampicillin, penicillin G, quinupristin/dalfopristin, linezolid, and vancomycin. The carrying rates of tetracycline resistance genes tetM, tetO and tetL in tetracycline resistant GBS strains were 75.0% (36/48), 33.3% (16/48) and 8.3% (4/48) respectively; carrying rates of erythromycin resistance genes ermB, mefA/E, ermA and ermTR were 72.7% (32/44), 22.7% (10/44), 18.2% (8/44) and 13.6% (6/44) respectively; carrying rate of clindamycin resistance gene linB was 42.9% (18/42). Erythromycin and clindamycin resistance phenotypes of GBS were mainly cMLSB (75.0%, 36/48), mostly mediated by ermB (44.4%, 16/36) and ermB+linB (27.8%, 10/36) genes. Conclusion Serotype Ⅲ is the most common GBS serotype in the reproductive tract of pregnant women. GBS is highly resistant to tetracycline, erythromycin and clindamycin. Tetracycline resistance is mainly mediated by tetM and tetO genes. Erythromycin resistance is mainly type cMLSB mediated by ermB gene, and clindamycin resistance is mainly mediated by linB gene.

Abstract:Objective To systematically evaluate the safety of fecal microbiota transplantation (FMT) for the treatment of recurrent Clostridium difficile infection (RCDI). Methods China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), WanFang Data, PubMed, EMbase, Web of Science, The Cochrane Library Database were searched by computer, randomized controlled trials on FMT treatment for RCDI were searched, the search time limit was from the establishment of database to January 16, 2022. Meta-analysis was conducted after two researchers independently screened the literatures, extracted the data and evaluated the bias risk included in the study. Results A total of 11 studies were included, involving 756 patients. All 11 studies reported the occurrence of adverse reactions after FMT treatment for RCDI. Descriptive analysis was conducted on the specific values of 7 studies without adverse reactions. Meta-analysis results of the other four studies showed that: compared with treatment for RCDI with vancomycin or fidaxomicin, freeze-dried fecal microbiota, and fresh fecal microbiota, as well as comparison between fresh fecal microbiota and autogenous fecal microbiota, incidence of adverse reactions in patients receiving frozen fecal microbiota was no significantly different (all P>0.05). Conclusion The available evidence shows that FMT is safe and effective for the treatment of RCDI, and there is no direct correlation between the adverse reactions of patients and FMT.

Abstract:Objective To establish an index system evaluating nursing staffs ability in the prevention and control of healthcare-associated infection (HAI), and provide objective standards for their relevant training and evaluation. Methods Evaluation index draft for the ability of nursing staff in preventing and controlling HAI was drawn up based on literature review and semi-structured interview. After screening and inviting 20 experts in the fields of infection prevention and control, nursing management and infectious diseases, draft was revised using Delphi method, and the final index weight was determined with analytic hierarchy process. Results Consultant positive coefficients from two rounds were both 100%, and authoritative coefficients were 0.874 and 0.882 respectively; Kendall's coefficients of concordance fell in the range of 0.139-0.545. Two rounds of expert consultation finally determined the evaluation index system of nursing staff's ability in preventing and controlling HAI, including three first-level indexes, 10 second-level indexes and 28 third-level indexes. Conclusion Establishment of the evaluation index system of nursing staff's ability in preventing and controlling HAI can provide basis for their training and evaluation.

Abstract:Objective To study the occurrence characteristics, emergency response, follow-up information as well as prevention and control cost of occupational exposure to blood-borne pathogens, and provide reference to formulating prevention and control strategies of occupational exposure in hospital. Methods Occupational exposure events of blood-borne pathogens reported from January 1, 2016 to December 31, 2020 in a tertiary first-class maternal and child health hospital were collected and analyzed retrospectively. Exposed persons who didn't complete the whole process of inspection and tracing were with telephone follow-up. Results There were 149 cases of occupational exposure to blood-borne pathogens. Incidence density of cleaning staff was the highest (0.036 cases/person/year), followed by nurses (0.031 cases/person/year), both were higher than that of doctors (0.018 cases/person/year) and medical technicians (0.005 cases/person/year) (P < 0.001). Incidence density of occupational exposure of nurses and doctors with junior and lower professional titles were higher than those with intermediate and senior professional titles (P < 0.001). Operating room was the location with the highest incidence (25.50%). Sharp instrument injury was the main exposure type (85.23%). Occupational exposure occurred most frequently during the disposal process of medical waste (34.90%). Hepatitis B virus is the most frequently exposed pathogen (20.81%). 10am-12am was the peak time of occupational exposure (28.86%). Hand was the most exposed site (82.55%), and injuries occurred more often in non-dominant hand (46.98%) than in dominant hand (35.57%). Index finger was the most common site of hand injury (42.28%). The top three causes of occupational exposure were careless operation (48.99%), accident or emergency (20.80%), and improper handling of sharp instruments by others (15.44%). 6.04% exposed persons had nonstandard emergency response, and 20.13% cases delayed reporting. The implementation rate of full tracing after occupational exposure was 41.89%, and the top three reasons for it were forgetting, not paying enough attention and wrong cognition. The total cost of the prevention and control after occupational exposure was 20 926.10 Yuan, with an average cost of 140.44 Yuan per case. The average cost of unknown exposure sources was the highest (273.70 Yuan per case). Conclusion Considering the characteristics of high-risk groups, locations, links, time and sites, as well as the high rate of delayed reporting and low implementation rate of full tracing of occupational exposure to blood-borne pathogens, it is necessary to take effective measures to reduce the occurrence of occupational exposure and decrease the risk of infection after exposure, thus ensure the occupational safety of hospital staff.

Abstract:Actinotignum schaalii (A. shaalii) is an emerging pathogen that may cause urinary tract infection and invasive infection. In 2022, pathogen in a blood culture specimen from a patient with acute urinary retention admitted to Guiqian International General Hospital was identified as A. schaalii by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), which is a facultative anaerobic Gram-positive coccobacillus. This case reported the first time that A. schaalii was detected in blood culture in China. After using ceftazidime for 5 days, infection symptoms of patient were significantly reduced, infection indicators returned to normal. Patient did not complain of fever and other discomfort and was discharged. This article discusses the clinical characteristics, identification and treatment of A. schaalii in combination with relevant literatures at home and abroad.

Abstract:Heteroresistance is a special type of drug resistance of bacteria, which is often characterized by diffe-rent bacterial subpopulations from the same clone presenting inconsistent drug resistance to certain antimicrobial agents. Most subpopulations are sensitive to a certain type of antimicrobial agent, while a small number of the subpopulations are resistant or highly resistant to it. Heteroresistance isolates often lead to the failure of anti-infection treatment of specific antimicrobial agents. Studies on heteroresistant bacteria are mainly focused on Gram-negative bacteria, while reports on Gram-positive cocci are rare. In recent years, studies have reported the emergence of Staphylococcus aureus isolates with heteroresistance to vancomycin, linezolid, oxacillin and other types of antimicrobial drugs, but its practical clinical significance remains to be further evaluated. In this paper, the latest advances in the mechanisms and detection technologies of Staphylococcus aureus heteroresistance were reviewed to provide new ideas for the research of bacterial heteroresistance mechanism and the development of noval detection technologies.

Abstract:Carbapenem-resistant Enterobacteriaceae (CRE) spreads widely in medical institutions. CRE infection is difficult to cure with high mortality, thus brings severe challenges to the clinic and society. Active screening on CRE from patients and environment as well as taking corresponding prevention and control strategies in medical institutions according to the screening results can reduce the spread of CRE in medical institutions. This article reviews the significance of active screening on CRE, the screening strategies for patients and hospital environment, as well as the prevention and control strategies for CRE, so as to provide theoretical support for the prevention and control of CRE in medical institutions.

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Abstract:美国感染病学会（IDSA）致力于为抗微生物药物耐药性感染的治疗提供最新指引。两份指引文件分别针对产超广谱β-内酰胺酶肠杆菌目细菌（ESBL-E）、耐碳青霉烯类肠杆菌目细菌（CRE）、难治性耐药铜绿假单胞菌（DTR-PA）和产AmpC β-内酰胺酶肠杆菌目细菌（AmpC-E）、耐碳青霉烯类鲍曼不动杆菌（CRAB）和嗜麦芽窄食单胞菌感染的治疗提供指导建议。与之前的指南比，已发表的关于AmpC-E、CRAB和嗜麦芽窄食单胞菌感染最佳治疗的数据相对较少，因此指引文件是基于临床经验、专家意见和对现有文献的回顾而提供的"指引"。在全球范围内，由于耐药菌的流行病学和特定抗感染药物的可获得性存在地区差异，指引文件主要侧重于美国的抗感染治疗，适用于成人和儿童。对于抗微生物药物耐药性感染的治疗，建议咨询感染病专家。此指引将每年更新。最新版本于2022年3月7日发布于https://www.idsociety.org/practice-guideline/amr-guidance/和2022年3月31日发布于https://www.idsociety.org/practice-guideline/amr-guidance-2.0/。