Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

In recent years, the research focus on health-related behavior and chronic non-communicable diseases has shifted from the analysis on independent effects of multiple causes on a single outcome to the evaluation the complex relationships between multiple causes and multiple effects. Complex network theory, an important branch of system science, considers the relationships among factors in a network and can reveal how health-related behaviors interact with chronic diseases through a series of complex network models and indicators. This paper summarizes the definition and development of complex network theory and its commonly used models, indicators, and case studies in the field of health-related behavior and chronic disease to promote the application of complex network theory in the field of health and provide reference and tools for future research of the relationship between health-related behavior and chronic disease.

Objective:To analyze the efficacy and safety of the L-DEP regimen (asparaginase, liposome doxorubicin, etoposide and methylprednisolone) as a salvage therapy for the refractory primary hemophagocytic lymphohistocytosis triggered by Epstein-Barr virus infection (EBV-pHLH) in children.Methods:In this retrospective case study, clinical and laboratory data before and after L-DEP regimen of 4 children diagnosed with EBV-pHLH in Beijing Children′s hospital between January 2016 and June 2022 were collected, and the efficacy and safety of L-DEP regimen for the treatment of EBV-pHLH were analyzed.Results:Among 4 patients, there were 3 females and 1 male with the age ranged from 0.8 to 7.0 years. Two of them showed compound heterozygous mutations of PRF1, one with a heterozygous mutation of UNC13D, one homozygous mutation of ITK. Before the L-DEP therapy, all of them had anemia and a soaring level of soluble CD25, 3 patients had neutropenia and thrombopenia, 3 patients had a high level of ferritin, 3 patients had hypofibrinogenemia and 1 patient had hypertriglyceridemia. After receiving 1 or 2 cycles of L-DEP treatment, three achieved remission, including complete remission (1 case) and partial remission (2 cases), and the other one had no remission. The levels of blood cell counts, soluble CD25, triglyceride, fibrinogen and albumin were recovered gradually in 3 patients who got remission. All four patients underwent hematopoietic stem cell transplantation (HSCT) after L-DEP regimen, and three survived. All patients had no severe chemotherapy related complications. The main side effects were bone marrow suppression, infection and pancreatitis, which recovered after appropriate treatments, apart from one who died from severe infection after urgent HSCT.Conclusion:L-DEP regimen could be served as an effective and safe salvage treatment for refractory pediatric EBV-pHLH, and also provide an opportunity for patients to receive HSCT.

Objective:To analyze the clinical features,treatment and prognosis of drug induced hypersensitivity syndrome related hemophagocytic lymphohistiocytosis (DIHS-HLH).Methods:This was a retrospective case study. Clinical characteristics, laboratory results, treatment and prognosis of 9 patients diagnosed with DIHS-HLH in Beijing Children′s hospital between January 2020 and December 2022 were summarized. Kaplan-Meier survival analysis was used to calculate the overall survival rate.Results:Among all 9 cases, there were 6 males and 3 females, with the age ranged from 0.8 to 3.1 years. All patients had fever, rash, hepatomegaly and multiple lymph node enlargement. Other manifestations included splenomegaly (4 cases), pulmonary imaging abnormalities (6 cases), central nervous system symptoms (3 cases), and watery diarrhea (3 cases). Most patients showed high levels of soluble-CD25 (8 cases), hepatic dysfunction (7 cases) and hyperferritinemia (7 cases). Other laboratory abnormalities included hemophagocytosis in bone marrow (5 cases), hypofibrinogenemia (3 cases) and hypertriglyceridemia (2 cases). Ascending levels of interleukin (IL) 5, IL-8 and interferon-γ (IFN-γ) were detected in more than 6 patients. All patients received high dose intravenous immunoglobulin, corticosteroid and ruxolitinib, among which 4 patients were also treated with high dose methylprednisolone, 2 patients with etoposide and 2 patients with cyclosporin A. After following up for 0.2-38.6 months, 7 patients survived, and the 1-year overall survival rate was (78±14)%. Two patients who had no response to high dose immunoglobulin, methylprednisolone 2 mg/(kg·d) and ruxolitinib died. Watery diarrhea, increased levels of IL-5 and IL-8 and decreased IgM were more frequently in patients who did not survive.Conclusions:For children with fever, rash and a suspicious medication history, when complicated with hepatomegaly, impaired liver function and high levels of IL-5 and IL-8, DIHS-HLH should be considered. Once diagnosed with DIHS-HLH, suspicious drugs should be stopped immediately, and high dose intravenous immunoglobulin, corticosteroid and ruxolitinib could be used to control disease.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Objective:To investigate the influencing factors for lymph node metastasis and prognosis in stage T1 and T2 esophageal squamous cell carcinoma after radical surgery and construct nomogram prediction models.Methods:The retrospective cohort study was conducted. The clinico-pathological data of 672 patients with T1 and T2 esophageal squamous cell carcinoma who were admitted to the Affiliated Hospital of North Sichuan Medical College from January 2014 to December 2019 were collected. There were 464 males and 208 females, aged (65±8)years. All patients under-went radical esophagectomy+2 or 3 field lymph node dissection. Observation indicators: (1) lymph node dissection, metastasis and follow-up. (2) risk factors for lymph node metastasis of esophageal cancer after radical resection. (3) prognostic factors of esophageal cancer after radical resection. (4) construction and evaluation of the prediction models of lymph node metastasis and prognosis of esophageal cancer after radical resection. Follow-up was conducted using outpatient examination, telephone and internet consultations to detect survival of patients up to April 2021. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Kaplan-Meier method was used to calculate survival rate and draw survival curve. Log-Rank test was used for survival analysis. Logistic regression model was used for univariate and multivariate analyses of risk for lymph node metastasis, and COX regression model was used for univariate and multivariate analyses of prognosis. Based on the results of multi-variate analysis, the nomogram prediction models for lymph node metastasis and prognosis predic-tion were constructed. The prediction discrimination of the nomogram models were evaluated using the area under curve (AUC) of the receiver operating characteristic curve (ROC). The calibration curve was used to evaluate the prediction consistency of the models. Results:(1) Lymph node dissection, metastasis and follow-up. The number of lymph node dissected was 14±8 and the number of lymph node metastasis was 2(range, 1?19) in 672 patients. Of the 672 patients, there were 182 cases had lymph node metastasis, including 58 cases in T1 stage and 124 cases in T2 stage. All 672 patients were followed up for 38 (range, 1?85)months. The average overall survival time of 672 patients was 65 months, with the 1-, 3-, 5-year overall survival rate as 89.0%, 74.3%, 66.0%, respectively. The average overall survival time of 325 patients in T1 stage and 347 patients in T2 stage were 70 months and 61 months. The 1-, 3-, 5-year overall survival rate of 325 patients in T1 stage and 347 patients in T2 stage were 95.0%, 83.5%, 73.4% and 87.4%, 69.9%, 59.2%, respectively, showing a significant difference in survival between them ( χ2=14.51, P<0.05). (2) Risk factors for lymph node metastasis of esophageal cancer after radical resection. Results of univariate analysis showed that tumor location, tumor histological grade, tumor T staging were related factors affecting lymph node metastasis of esophageal cancer after radical resection ( odds ratio=1.40, 1.54, 2.56, 95% confidence interval as 1.07?1.85, 1.20?1.99, 1.79-3.67, P<0.05). Results of multivariate analysis showed that tumor location, tumor histological grade, tumor T staging were independent factors affecting lymph node metastasis ( odds ratio=1.42, 1.61, 2.63, 95% confidence interval as 1.07?1.89, 1.25?2.09, 1.82?3.78, P<0.05). (3) Prognostic factors of esophageal cancer after radical resection. Results of univariate analysis showed that preoperative comorbidities, postoperative complications, tumor histological grade (G3), tumor T staging, tumor N staging (N1 stage, N2 stage, N3 stage), tumor TNM staging (Ⅲ stage, Ⅳ stage) were related factors affecting prognosis of esophageal cancer after radical resection ( hazard ratio= 1.48, 1.64, 2.23, 1.85, 2.09, 4.48, 4.97, 3.54, 5.53, 95% confidence interval as 1.08?2.03, 1.20?2.23, 1.47?3.39, 1.34?2.54, 1.44?3.04, 2.89?6.95, 1.57?15.73, 2.48?5.05, 1.73?17.68, P<0.05). Results of multivariate analysis showed that preoperative comorbidities, G3 of tumor histological grade, T2 stage of tumor T staging, N1 stage, N2 stage, N3 stage of tumor N staging were independent risk factors affecting prognosis of esophageal cancer after radical resection ( hazard ratio=1.57, 1.89, 1.63, 1.71, 3.72, 3.90, 95% confidence interval as 1.14?2.16, 1.23?2.91, 1.17?2.26, 1.16?2.51, 2.37?5.83, 1.22?12.45, P<0.05). (4) Construction and evaluation of the prediction models of lymph node metastasis and prognosis of esophageal cancer after radical resection. Based on the results of multivariate analysis, tumor location, tumor histological grade, tumor T staging were applied to construct a nomo-gram model for lymph node metastasis prediction of esophageal cancer after radical resection, the score of tumor location, tumor histological grade, tumor T staging were 82, 100, 100, respectively, and the sum of the scores corresponding to the lymph node metastasis rate. Preoperative comor-bidity, tumor histological grade, tumor T staging, tumor N staging were applied to construct a nomo-gram model for 1-, 3-, 5-year overall survival rate prediction of esophageal cancer after radical resection, the score of preoperative comorbidity, tumor histological grade, tumor T staging, tumor N staging were 23, 38, 27, 100, respectively, and the sum of the scores corres-ponding to the 1-, 3-, 5-year overall survival rate. Results of ROC showed that the AUC of nomogram model for lymph node metastasis prediction after radical esophagectomy was 0.66 (95% confidence interval as 0.62?0.71, P<0.05). The AUC of nomogram model for 1-, 3-, 5-year overall survival rate prediction after radical esophagectomy were 0.73, 0.74, 0.71 (95% confidence intervals as 0.66?0.80, 0.68?0.79, 0.65?0.78, P<0.05). Results of calibration curve showed that the predicted lymph node metastasis rate and the predicted 1-, 3-, 5-year overall survival rate by nomogram models were consistent with the actual lymph node metastasis rate and 1-, 3-, 5-year overall survival rate. Conclusions:Tumor location, tumor histological grade, tumor T staging are independent factors affecting lymph node metastasis in T1 and T2 esophageal squamous cell carcinoma after radical surgery and nomogram model constructed by these indicators can predict the lymph node metas-tasis rate. Preoperative comor-bidities, G3 of tumor histological grade, T2 stage of tumor T staging, N1 stage, N2 stage, N3 stage of tumor N staging are independent risk factors affecting prognosis and nomogram model constructed by these indicators can predict the overall survival rate of patients after surgery.

Objective:To understand the clinical characteristics and prognosis of Langerhans cell histiocytosis (LCH) with skin-limited lesion.Methods:A retrospective analysis was performed on clinical characteristics and prognosis of 16 skin-limited LCH patients, out of 578 LCH patients who were hospitalized in Beijing Children′s Hospital during December 2013 to June 2018.Results:A total of 16 skin-limited LCH cases, accounted for 2.7% of all 578 cases, were included.Among which, sex ratio (male vs.female) was 1.28∶1.00.Median ages of skin eruption occurrence and of diagnosis of the disease were 3.5 months (3 days to 2 years and 5 months) and 6 months (2 months 14 days to 2 years and 8 months) in this group.Among the 16 cases, seborrheic dermatitis-like lesions(11 cases, 68.7%) was the most common, and the trunk was most frequently involved[75.0% (12 cases)]. Serine/threonine protein kinase gene V600E [ BRAF (p.V600E)] mutation was detected in pathological specimens from 10 skin-limi-ted cases, with 9 cases being positive.Plasma samples from 5 positive cases were further detected for BRAF (p.V600E) mutation, and 4 positive results were gained.Of all 16 patients, 11 cases (68.7%) were treated.Remission were achieved in 3-6 months from treatment start in patients treated whether according to the Histiocyte Society′s LCH-2009 protocol for 25 weeks(6 cases, 37.5%), or with topical mometasonefuroate for 3 months (3 cases, 18.8%). Two patients(12.5%) with solitary cutaneous lesions underwent excision biopsy (one face and one prepuce) and were considered to be in remission immediately after surgery.None of these patients suffered from the recurrence of the disease.The remaining 5 patients (31.3%) with skin-limited LCH were just evaluated regularly, and achieved remission in 3-6 months of commencing observation.Among these untreated patients, 1 with consistently positive BRAF (p.V600E) mutation in plasma had bone involvement in the 24 th month of assessment, and was then treated based on the Histiocyte Society′s LCH-2009 Protocol.No clinical or imageological evidence supporting disease progression was found on this patient.Median follow-up period was 32.8 months (2.9-63.9 months). Except one patient, none of the rest cases had active disease till follow-up ended.Two-year event free survival(EFS) of this research was (92.3± 7.4)%.There was no significant difference between EFS of treated group and that of observation group( χ2=1.250, P=0.264). Conclusions:Skin-limited LCH often occurs in infants and newborns, with strong heterogeneity in clinical manifestations, laboratory indicators, and pathogenesis.Seborrheic dermatitis-like lesions were the most common cutaneous type.The prognosis of the patients is excellent despite progressing into multisystem involvement can be seen in a few patients.

Objective:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2018 to December 2019. Antibiotic susceptibility tests were conducted with agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 14 778 bacterial strains were collected from 50 hospitals, of which 4 117 (27.9%) were Gram-positive bacteria and 10 661(72.1%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.2%), Klebsiella pneumoniae (17.0%), Staphylococcus aureus (9.7%), coagulase-negative Staphylococci (8.7%), Pseudomonas aeruginosa (3.7%), Enterococcus faecium (3.4%), Acinetobacter baumannii(3.4%), Enterobacter cloacae (2.9%), Streptococci(2.8%) and Enterococcus faecalis (2.3%). The the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus were 27.4% (394/1 438) and 70.4% (905/1 285), respectively. No glycopeptide-resistant Staphylococcus was detected. More than 95% of S. aureus were sensitive to amikacin, rifampicin and SMZco. The resistance rate of E. faecium to vancomycin was 0.4% (2/504), and no vancomycin-resistant E. faecalis was detected. The ESBLs-producing rates in no carbapenem-resistance E. coli, carbapenem sensitive K. pneumoniae and Proteus were 50.4% (2 731/5 415), 24.6% (493/2001) and 35.2% (31/88), respectively. The prevalence of carbapenem-resistance in E. coli and K. pneumoniae were 1.5% (85/5 500), 20.6% (518/2 519), respectively. 8.3% (27/325) of carbapenem-resistance K. pneumoniae was resistant to ceftazidime/avibactam combination. The resistance rates of A. baumannii to polymyxin and tigecycline were 2.8% (14/501) and 3.4% (17/501) respectively, and that of P. aeruginosa to carbapenem were 18.9% (103/546). Conclusions:The surveillance results from 2018 to 2019 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while E. coli was the most common pathogen, and ESBLs-producing strains were in majority; the MRSA incidence is getting lower in China; carbapenem-resistant E. coli keeps at a low level, while carbapenem-resistant K. pneumoniae is on the rise obviously.