Analysis of the Current Situation and Risk Factors of Lower Respiratory Tract Infection among ICU Patients in Guizhou,China During 2019-2022

Objective:This study aims to explore the prevalence,features,and risk factors of lower respiratory tract infections(LRTIs)in the intensive care unit(ICU)of a newly established hospital in Zunyi City.The goal is to devise strategies for preventing LRTIs in the ICU of new hospitals,thereby mitigating the incidence of nosocomial LRTIs in ICU patients.Methods:A case-control study was conducted from March 2019 to December 2022 to investigate the incidence rate of LRTIs in the ICU of a newly constructed hospital in Zunyi City.Patients with LRTIs constituted the case group,while those without LRTIs constituted the control group,where a 1:1 matching principle was adhered to.A single-factor chi-square(χ2)test was employed to analyze the risk factors,with independent risk factors being explored using a multivariate logistic regression analysis.Results:A total of 169 strains of pathogenic bacteria were isolated,comprising 66.28%gram-negative bacteria,17.75%gram-positive bacteria,and 15.97%fungi.The most prevalent pathogens included Acinetobacter baumannii(43.20%),Candida albicans(10.65%),and Pseudomonas aeruginosa(8.88%).Of the 82 strains infected by multidrug-resistant bacteria in patients with LRTIs,81.7%were carbapenem-resistant Acinetobacter baumannii,9.8%were multidrug-resistant Pseudomonas aeruginosa,and 6.1%were carbapenem-resistant Escherichia coli.Identified risk factors included smoking history,total hospitalization days,ICU stay length,hypoproteinemia,indwelling gastric tube,intubation type,duration of mechanical ventilation,usage of antibacterial drugs,and administration of protein drugs(P<0.05).Multivariate logistic regression analysis demonstrated that these factors were independent risk factors for nosocomial LRTIs in ICU patients(P<0.05).Conclusion:ICU patients in our hospital were mainly infected by carbapenem-resistant Acinetobacter baumannii.To prevent LRTIs in patients,tailored preventive measures should be developed and the rational use of antibacterial drugs should be promoted.

Prevalence and antimicrobial susceptibility patterns of bacteria in ICU patients with lower respiratory tract infection: A cross-sectional study

Objective: To investigate the prevalence of isolated organisms in patients with lower respiratory tract infections and the antibiotic susceptibilities at a tertiary care center. Methods: In this observational and cross-sectional analysis, 114 patients admitted in the intensive care unit were enrolled. The endotracheal aspirates and bronchoalveolar lavage were collected. The bacteria were isolated and identified, and finally, antimicrobial sensitive pattern of the isolated bacteria was examined. Results: The prevalence of infection was 72.72% in male patients and 27.28% in females. The predominant bacteria were Klebsiella pneumoniae (37.50%) followed by Acinetobacter spp. (36.36%), Pseudomonas aeruginosa (7.95%),Escherichia coli (6.81%), Proteus mirabilis (2.27%), atypical Escherichia coli (1.13%), Enterococcus spp. (1.13%),Elizabethkingia meningoseptica (1.13%),Staphylococcus aureus (1.13%),Proteus vulgaris (1.13%), Citrobacter freundii (1.13%), and Citrobacter koseri (1.13%). High resistance to cephalosporins (82.18%) was demonstrated in all Gram-negative bacteria. Bacteria showed susceptibility to colistin (88.75%) followed by tigecycline (83.11%), gentamycin (36.18%), and amikacin (49.23%). Conclusions: As the most frequent respiratory organisms, Klebsiella pneumoniae and Acinetobacter spp. have increased resistance to cephalosporins and susceptibility to colistin followed by tigecycline.

Validation of a Risk-Based Biomarker-Enhanced Scoring System for Lower Respiratory Tract Infections (OPTIMA I Basel)—An Observational Survey

Background: Despiteits recommendation in management guide lines for community acquired pneumonia (CAP), the CURB65 score is frequently not followed for disposition decisions in clinical routine. We therefore proposed an improved CURB65 A score, supplemented by proadre nome dull in (ProADM) levels for patients with CAP and other lower respiratory tract infections (LRTIs). In this study, we vali dated this risk based biomarker enhanced disposition in patients with LRTIs presenting to the emergency department of the University Hospital of Basel. Methods: In this prospective observational cohort study of 85 patients presenting with LRTIs, site of care was decided by the physicians in charge according to their judgement. Retro spectively the CURB65 A score was calculated and a virtual disposition assigned. This was compared with the existing disposition in order to identify efficacy of the novel risk based biomarker enhanced disposition. Results: The novel disposition criteria considered 14 patients suitable for outpatient treatment compared to 11 in the current disposition (p = 0.5). It detected 7 patients to be best treated outside the hospital for nursing reasons, while the current disposition detected only 1 patient requiring geriatric care (p = 0.09). Further, it decreased regular hospitalizations considerably (32 vs. 64, p 0.001). Conclusions: The novel risk based biomarker enhanced disposition is an objective, safe and probably more efficient disposition system to identify outpatient treatment options than the current practice at the University Hospital of Basel.

Assessing the quality of the management skills required for lower respiratory tract infections in Kilimanjaro, Tanzania

Background: Lower respiratory tract infections (LRTI) are among the leading causes of morbidity and mortality. A severe form of atypical pneumonia, Q fever, has been found in Northern Tanzania. Assessment of the quality of health care for lower respiratory tract infection from the clinicians’ performance has rarely been performed. Methods: A cross sectional descriptive study using the qualitative and quantitative approaches for assessing clinicians and patient files from 11 health facilities of Kilimanjaro region. The facilities were of 4 different levels of public health care delivery and 1 private independent hospital. Results: Medications for LRTI were highly variable in 346 files and from attempts of treatment reported in 53 clinician’s interviews. No file showed attempts for assessing the severity of Pneumonia. Only 6 (11.1%) clinicians could mention causes of atypical pneumonia. Only 7 clinicians (13.0%) were aware of Q-fever and could mention the cause. The quality of clinical records for monitoring the progress was not the same in all levels of care and the difference in availability was statistically significant as level of mental state χ2 (4) = 139.4;P

Respiratory Virus Multiplex RT-PCR Assay Sensitivities and Influence Factors in Hospitalized Children with Lower Respiratory Tract Infections

Multiplex RT-PCR assays have been widely used tools for detection and differentiation of a panel of respiratory viral pathogens. In this study, we evaluated the Qiagen ResPlex lI V2.0 kit and explored factors influencing its sensitivity. Nasopharyngeal swab （NPS） specimens were prospectively collected from pediatric inpatients with lower respiratory tract infections at the time of admission in the Shenzhen Children＇s Hospital from May 2009 to April 2010. Total nucleic acids were extracted using the EZ1 system （Qiagen, Germany） and 17 respiratory viruses and genotypes including influenza A virus （FluA）, FluB, parainfluenza virus 1 （PIV1）, PIV2, PIV3, PIV4, respiratory syncytial virus （RSV）, human metapneumovirus （hMPV）, rhinoviruses （RhV）, enteroviruses （EnV）, human bocaviruses （hBoV）, adenoviruses （AdV）, four coronaviruses （229E, OC43, NL63 and HKU1）, and FluA 2009 pandemic H1NI（H1NI-p） were detected and identified by the ResPlex II kit. In parallel, 16 real-time TaqMan quantitative RT-PCR assays were used to quantitatively detect each virus except for RhV. Influenza and parainfluenza viral cultures were also performed. Among the total 438 NPS specimens collected during the study period, one or more viral pathogens were detected in 274 （62.6%） and 201（45.9%） specimens by monoplex TaqMan RT-PCR and multiplex ResPlex, respectively. When results from monoplex PCR or cell culture were used as the reference standard, the multiplex PCR possessed specificities of 92.9-100.0%. The sensitivity of multiplex PCR for PIV3, hMPV, PIV1 and BoV were 73.1%, 70%, 66.7% and 55.6%, respectively, while low sensitivities （11.1%-40.0%） were observed for FluA, EnV, OC43, RSV and H1N1. Among the seven viruses/genotypes detected with higher frequencies, multiplex PCR sensitivities were correlated significantly with viral loads determined by the TaqMan RT-PCR in FluA, H 1N 1-p and RSV （p=0.011-0.000） The Qiagen ResPlex II multiplex RT-PCR kit possesses excellent specificity for simultaneous detection of 17 viral pathogens in NPS specimens in pediatric inpatients at the time of admission. The sensitivity of multiplex RT-PCR was influenced by viral loads, specimen process methods, primer and probe design and amplification condition.

Human bocavirus infection in children hospitalized with lower respiratory tract infections:Does viral load affect disease course?

Objective:To examine the effects of human bocavirus type 1(HBoV1)on the course of lower respiratory tract infections in cases of monoinfection and coinfection,and the effects of HBoV1 viral load on the disease in children under six years old hospitalized with a diagnosis of HBoV1-associated lower respiratory tract infections.Methods:Children under six years of age,who were hospitalized with the diagnosis of lower respiratory tract infection due to HBoV1 between 1 January 2021 and 1 January 2022 were included in the study.Laboratory confirmation of the respiratory pathogens was performed using polymerase chain reaction(PCR).Results:Fifty-four(16.4%)children with HBoV1 among 329 children whose PCR was positive with bacterial/viral agent in nasopharyngeal swab samples were included in the study.There were 28(51.9%)males and 26(48.1%)females with a median age 23.4 months[interquartile range(IQR):13.2,30.0 months](min-max:1 month-68 months).HBoV1 was detected as a monoinfecton in 26(48.1%)children,and as a coinfection with other respiratory agents in 28 children(51.9%).In multiple regression analysis,coinfection(P=0.032)was associated with the length of hospitalization(P<0.001;R^(2)=0.166).There was a negative correlation(r=−0.281,P=0.040)between cough and cycle threshold.Fever was found to be positively correlated with C-reactive protein(r=0.568,P<0.001)and procalcitonin(r=0.472;P=0.001).Conclusions:Although we found a higher HBoV1 viral load in children with more cough symptoms in our study,it had no effect on the severity of the disease,such as length of hospital stay and need for intensive care.Coinfection was found to affect the length of hospitalization.

Association between early viral lower respiratory tract infections and subsequent asthma development

BACKGROUND The association between hospitalization for human respiratory syncytial virus(HRSV)bronchiolitis in early childhood and subsequent asthma is well established.The long-term prognosis for non-bronchiolitis lower respiratory tract infections(LRTI)caused by viruses different from HRSV and rhinovirus,on the other hand,has received less interest.AIM To investigate the relationship between infant LRTI and later asthma and examine the influence of confounding factors.METHODS The PubMed and Global Index Medicus bibliographic databases were used to search for articles published up to October 2021 for this systematic review.We included cohort studies comparing the incidence of asthma between patients with and without LRTI at≤2 years regardless of the virus responsible.The meta-analysis was performed using the random effects model.Sources of heterogeneity were assessed by stratified analyses.RESULTS This review included 15 articles(18 unique studies)that met the inclusion criteria.LRTIs at≤2 years were associated with an increased risk of subsequent asthma up to 20 years[odds ratio(OR)=5.0,95%CI:3.3-7.5],with doctor-diagnosed asthma(OR=5.3,95%CI:3.3-8.6),current asthma(OR=5.4,95%CI:2.7-10.6),and current medication for asthma(OR=1.2,95%CI:0.7-3.9).Our overall estimates were not affected by publication bias(P=0.671),but there was significant heterogeneity[I 2=58.8%(30.6-75.5)].Compared to studies with hospitalized controls without LRTI,those with ambulatory controls had a significantly higher strength of association between LRTIs and subsequent asthma.The strength of the association between LRTIs and later asthma varied significantly by country and age at the time of the interview.The sensitivity analyses including only studies with similar proportions of confounding factors(gender,age at LRTI development,age at interview,gestational age,birth weight,weight,height,smoking exposure,crowding,family history of atopy,and family history of asthma)between cases and controls did not alter the overall estimates.CONCLUSION Regardless of the causative virus and confounding factors,viral LRTIs in children<2 years are associated with an increased risk of developing a subsequent asthma.Parents and pediatricians should be informed of this risk.

Simultaneous Detection of 13 Key Bacterial Respiratory Pathogens by Combination of Multiplex PCR and Capillary Electrophoresis

Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction （PCR） and capillary electrophoresis （MPCE） assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catorrholis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebactefium diphthefiae, and Streptococcus pyogenes. Methods Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. Results The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10-7 to 10-2 ng/μL. Furthermore, analysis of the 252 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. Conclusion This study revealed that the MPCE with high specificity and sensitivity. This assay survey of respiratory pathogens. assay is a rapid, reliable, and high-throughput method has great potential in the molecular epidemiological.

肺泡灌洗液mNGS检测神经外科重症下呼吸道感染病原的应用

目的分析宏基因二代测序(mNGS)技术对神经外科重症下呼吸道感染患者肺泡灌洗液中病原体和肺炎克雷伯菌耐药基因检测。方法选取2020年6月至2022年6月河南省人民医院收治的196例神经外科重症下呼吸道感染患者作为研究对象。采集患者的肺泡灌洗液标本进行常规病原学与mNGS技术检测,对病原体进行分离鉴定,并计算2种检测方法的差异性;并检测肺炎克雷伯菌的耐药基因与药敏试验结果。结果常规病原学检测的阳性率为62.42%(122/196),mNGS技术检测阳性率为88.27%(173/196),mNGS技术检测高于常规病原学检测(χ^(2)=35.631,P<0.05);肺炎克雷伯菌经mNGS技术检出耐药基因包括超广谱β-内酰胺酶基因(SHV、TEM)与碳青霉烯酶基因(KPC);药敏试验结果显示,肺炎克雷伯菌对头孢唑林、头孢呋辛及头孢曲松的耐药率较高,分别为75.00%、66.67%及54.17%,对比阿培南及美罗培南的耐药率较低,分别为16.67%及12.50%。结论mNGS技术能够有效提高神经外科重症下呼吸道感染阳性检出率,可辅助评估肺炎克雷伯菌抗菌药物耐药性基因。

呼出气一氧化氮、肺泡一氧化氮和嗜酸性粒细胞对3~6岁儿童呼吸系统疾病的鉴别诊断价值

目的探讨呼出气一氧化氮(FeNO)、肺泡一氧化氮(CaNO)和嗜酸性粒细胞(EOS)在甘肃省兰州市3~6岁儿童呼吸系统疾病鉴别诊断中的应用价值。方法选取确诊哮喘或过敏性鼻炎或下呼吸道感染的360例3~6岁儿童作为研究对象,采用斯皮尔曼秩相关系数评估FeNO、CaNO、EOS的相关性,通过随机森林模型、受试者工作特征(ROC)曲线、多因素逻辑回归分析评估FeNO、CaNO和EOS对3种疾病的鉴别诊断价值。结果哮喘患儿的FeNO、CaNO中位数高于其他疾病患儿,过敏性鼻炎患儿的EOS中位数最低,下呼吸道感染患儿的FeNO、CaNO中位数最低。相关性分析结果显示,FeNO与CaNO呈正相关(r=0.59,P<0.05),FeNO与EOS呈负相关(r=-0.61,P<0.05),CaNO与EOS呈负相关(r=-0.63,P<0.05)。随机森林模型显示,FeNO在疾病分类中的重要性最高。ROC曲线分析结果显示,3种疾病中,FeNO、CaNO、EOS对下呼吸道感染的诊断效能均最高(曲线下面积分别为0.86、0.91、1.00)。多因素逻辑回归模型诊断哮喘的曲线下面积为0.96,灵敏度为0.902,特异度为0.881。结论FeNO、CaNO和EOS在鉴别诊断兰州地区3~6岁儿童哮喘、过敏性鼻炎、下呼吸道感染方面展现出较好的潜力,且基于三者构建的多因素逻辑回归模型可有效提升对哮喘的诊断准确性。

急性下呼吸道感染患儿支气管肺泡灌洗液病原菌特征分析

目的研究急性下呼吸道感染患儿病原菌特点,探讨支气管肺泡灌洗液荧光PCR检测对儿童急性呼吸道感染病原学的诊断价值。方法选择2018年6月至2019年5月吉林大学第一医院收治的急性呼吸道感染住院患儿172例为研究对象,收集其支气管肺泡灌洗液,通过多重实时荧光定量PCR检测其病原体。结果本研究中172例支气管肺泡灌洗液样本致病菌检出有106例,阳性率为61.63%(106/172);排在前三位的病原菌检出率依次为肺炎链球菌26.74%(46/172),流感嗜血杆菌17.44%(30/172),百日咳鲍特菌8.14%(14/172),且不同年龄组的病原菌检出率存在差异,P<0.01。结论急性下呼吸道感染患儿支气管肺泡灌洗液中肺炎链球菌检出率最高,依次为流感嗜血杆菌、百日咳鲍特菌、卡他莫兰汉菌、金黄色葡萄球菌。急性下呼吸道感染患儿的病原菌检出率在不同年龄段分组中存在差异。

红细胞分布宽度与血小板分布宽度可以辅助预测流感合并下呼吸道感染患者预后

目的探讨血细胞计数及相关参数是否可以预测流感合并下呼吸道感染患者的预后。方法回顾性研究2013年至2023年首都医科大学附属北京朝阳医院经急诊医学科、发热门诊或呼吸科收治入院或留观的流感合并下呼吸道感染患者,以28天死亡为研究终点,分为生存组和死亡组,比较分析两组间血细胞计数及相关参数的差异,回归分析死亡的独立预测因素,建模并对模型进行评价。结果此项研究最终纳入417例患者,28天生存组361例(86.6%),死亡组56例(13.4%)。死亡组淋巴细胞计数和血小板计数显著低于生存组,红细胞分布宽度、血小板分布宽度、血小板平均体积及大血小板比率显著高于生存组(P<0.05)。多变量Logistic回归分析筛选独立相关变量,当淋巴细胞计数≤0.68×10^(9)/L,或血小板计数≤147×10^(9)/L,或红细胞分布宽度>12.7%,或血小板分布宽度>13.9 fL时,患者28天死亡风险增加,四个指标建立预测模型的AUC为0.734(95%CI 0.664~0.804),敏感度58.9%,特异度80.4%,阳性预测值32.0%,阴性预测值92.7%,阳性似然比3.01,阴性似然比0.51。模型的一致性指数为0.735,拟合优度Hosmer-Lemeshow检验显示拟合效果较好(P=0.406)。结论淋巴细胞计数、血小板计数、红细胞分布宽度、血小板分布宽度可作为早期预测流感合并下呼吸道感染患者28天死亡风险的指标,以这些指标构建的列线图模型可计算临床实测值所对应的死亡风险概率。

肺炎克雷伯菌致下呼吸道感染患者常用抗菌药物的耐药性分析

目的分析肺炎克雷伯菌(Klebsiella pneumoniae,KPN)致下呼吸道感染(lower respiratory tract infection,LRI)患者对常用抗菌药物的耐药性。方法选取2022年10月至2023年9月我院KPN致LRI患者514例,采集痰标本,统计KPN、超广谱β-内酰胺酶(EBLS)+菌株、EBLS菌株、耐碳青霉烯类肺炎克雷伯菌(CRKP)检出情况,行药敏试验,分析KPN、EBLS+菌株、EBLS菌株及CRKP菌株对常用抗菌药物的耐药性。结果分离出514株KPN,其中EBLS+菌株94株(18.3%)、EBLS菌株310株(60.3%)、CRKP菌株110株(21.4%);KPN对替加环素最为敏感,达99.8%;EBLS+菌株对大部分常用抗菌药物的耐药率较EBLS菌株高;除替加环素外,CRKP菌株对其他常用抗菌药物的耐药率均较高,>80.0%。结论KPN致LRI患者中分离出EBLS+菌株、EBLS菌株及CRKP菌株,不同菌株对不同抗菌药物耐药率不同,需进行细菌培养与鉴定,了解其耐药率,帮助临床医师合理选择抗菌药物进行治疗。

Diagnostic Value of Nasopharyngeal Aspirates in Children with Lower Respiratory Tract Infections

Background： The accuracy of nasopharyngeal aspirate （NPA） specimens in detecting lower respiratory pathogens remains controversial. The objective of this study was to evaluate the diagnostic accuracy of aspirates （NPAs） specimen in lower respiratory tract infections （LRTIs） in children. Methods： The prospective study was designed to collect the data of paired NPAs and bronchoalveolar lavage fluids from children with acute LRTIs from January 2013 to December 2015. All specimens were subjected to pathogen detection： bacterial detection by culture, Mvcoplasma pneumoniae （Mp） detection by polymerase chain reaction assay and virus （influenza A and B viruses, parainfluenza virus [PIV] Types 1 and 3, respiratory syncytial virus, and adenovirus） detection by immunofluorescence assay. The diagnostic accuracy analysis of NPAs was stratified by age ≤3 years （n = 194） and 〉3 years （n = 294）. Results： We collected paired specimens from 488 children. The positive rate of pathogen was 61.6%. For Streptococcus pneumoniae, NPA culture had the specificity of 89.9% and negative predictive value of 100% in age ≤3 years, the specificity of 97.2% and negative predictive value of 98.9% in age 〉3 years. For Mp, the positive predictive values of NPA was 77.4% in children ≤3 years, and 89.1% in children 〉3 years. For PIV III, NPA specimen had the specificity of 99.8% and negative predictive value of 96.5% in children ≤3 years. For adenovirus, NPA had the specificity of 97.8% and negative predictive value of 98.4% in age ≤3 years, the specificity of 98.9% and negative predictive value of 99.3% in age 〉3 years. Conclusions： NPAs are less invasive diagnostic respiratory specimens, a negative NPA result is helpful in ＂rule out＂ lower airway infection; however, a positive result does not reliably ＂rule in＂ the presence of pathogens.

清金化痰汤治疗糖尿病合并下呼吸道感染临床观察

目的分析清金化痰汤加减治疗糖尿病合并下呼吸道感染的可行性。方法拟选取宜丰县人民医院2021年1月—2022年12月收治的糖尿病合并下呼吸道感染患者60例,分为对照组、观察组,各30例。统计分析两组临床症状恢复时间(发热、咳嗽、全身症状、局部症状)、血糖情况、炎症因子水平[白细胞、C反应蛋白(CRP)]、并发症发生情况(消化道反应、皮疹、心动过缓等)、临床疗效。结果治疗后,观察组患者的发热、咳嗽、局部症状、全身症状恢复时间均短于对照组(P<0.05);观察组空腹血糖水平、餐后2 h血糖水平、白细胞计数、CRP水平均低于对照组(P<0.05);观察组并发症总发生率3.33%(1/30)低于对照组的26.67%(8/30)(P<0.05);观察组治疗总有效率96.67%(29/30)高于对照组的73.33%(22/30)(P<0.05)。结论清金化痰汤加减治疗糖尿病合并下呼吸道感染的可行性高。

体积描记法联合血清单核细胞趋化蛋白-1水平预测急性下呼吸道感染患者合并哮喘的效能分析

目的探究体积描记法联合血清单核细胞趋化蛋白-1(MCP-1)对急性下呼吸道感染患者合并哮喘的预测价值。方法回顾性分析2019年6月—2022年12月青海省人民医院收治的188例急性下呼吸道感染患者的病历资料。根据患者住院期间是否并发哮喘分为合并组(48例)和非合并组(140例)。收集并整理所有受试者的人口学资料和实验室检测指标(体积描记法相关参数:肺总量、残气量、残气率,血清MCP-1水平)。比较两组患者临床资料的差异,分析肺总量、残气量与功能残气量(FRC)、MCP-1的相关性,分析影响急性下呼吸道感染患者并发哮喘的相关因素,以及FRC、MCP-1对急性下呼吸道感染患者并发哮喘的预测价值。结果合并组FRC、肺总量、残气量、残气率、MCP-1水平均高于非合并组(P<0.05)。FRC与肺总量、残气量水平均呈正相关(r=0.681和0.671,均P=0.001);MCP-1与肺总量、残气量水平均呈正相关(r=0.669和0.654,均P=0.001)。多因素逐步Logistic回归分析结果显示:FRC[O^R=2.450(95%CI:1.239,4.840)]、MCP-1[O^R=2.995(95%CI:1.516,5.918)]是急性下呼吸道感染患者并发哮喘的危险因素(P<0.05)。受试者工作特征曲线结果分析显示,FRC、MCP-1及联合预测急性下呼吸道感染患者并发哮喘的敏感性分别为72.92%(95%CI:0.579,0.842)、83.33%(95%CI:0.692,0.920)、79.17%(95%CI:0.645,0.890),特异性分别为81.43%(95%CI:0.737,0.873)、70.71%(95%CI:0.623,0.779)、81.43%(95%CI:0.737,0.873)。结论体积描记法和血清MCP-1水平可用于评估急性下呼吸道感染患者肺功能,且血清MCP-1与体积描记法检测的FRC对急性下呼吸道感染患者并发哮喘的预测效能良好。

Pharmacokinetic-pharmacodynamic analysis of ciprofloxacin in elderly Chinese patients with lower respiratory tract infections caused by Gram-negative bacteria

Background: Ciprofloxacin is usually used in the treatment of lower respiratory tract infections (LRTIs). Recent studies abroad shown ciprofloxacin is inadequately dosed and might lead to worse outcomes. The aim of this study was to perform pharmacokinetic and pharmacodynamic analyses of ciprofloxacin in elderly Chinese patients with severe LRTIs caused by Gramnegative bacteria. Methods: From September 2012 to June 2014, as many as 33 patients were empirically administered beta-lactam and ciprofloxacin combination therapy. Patients were infused with 200 or 400 mg of ciprofloxacin every 12 h, which was determined empirically by the attending physician based on the severity of the LRTI and the patienfs renal condition. Ciprofloxacin serum concentrations were determined by high-performance liquid chromatography. Bacterial culture was performed from sputum samples and/or endotracheal aspirates, and the minimum inhibitory concentrations (MICs) of ciprofloxacin were determined. The ratios of the area under the serum concentration-time curve to the MIC (AUC/MIC) and of the maximum serum concentration of the drug to the MIC (Cmax/MIC) were calculated. The baseline data and pharmacokinetic parameters were compared between clinical success group and clinical failure group, bacteriologic success group and bacteriologic failure group. Results: Among the 33 patients enrolled in the study, 17 were infected with Pseudomonas aeruginosa, 14 were infected with Acinetobacter baumannii^ and two were infected with Klebsiella pneumoniae. The mean age of the patients was 76.9 土 6.7 years. Thirty-one patients (93.4%) did not reach the target AUC/MIC value of >125, and 29 patients (87.9%) did not reach the target Cmax/MIC value of >8. The AUC/MIC and Cniax/MIC ratios in the clinical success group were significantly higher than those in the clinical failure group (61.1 [31.7-214.9] vs. 10.4 [3.8-66.1], Z =-4.157;9.6 [4.2-17.8] vs, 1.3 [0.4-4.7], Z =-4.018;both P< 0.001). The AUC/MIC and Cmax/MIC ratios in the patients for whom the pathogens were eradicated were significantly higher than those in the patients without the pathogens eradicated (75.3 [31.7-214.9] vs. 10.5 [3.8-66.1], Z =—3.938;11.4 [4.2-17.8] vs. 1.4 [0.4-5.4], Z =—3.793;P < 0.001 for both). Receiver operating characteristic curve analysis showed that the AUC/MIC and Cmax/ MIC values were closely associated with clinical and bacteriologic efficacies (P<0.001 in both). Conclusions: Ciprofloxacin is inadequately dosed against Gram-negative bacteria, especially for those with relatively high MIC values. Consequently, the target values, AUC/MIC > 125 and Cmax/MIC> 8, cannot be reached.

Clinical characteristics and molecular epidemiology of human metapneumovirus in children with acute lower respiratory tract infections in China, 2017 to 2019: A multicentre prospective observational study

Human metapneumovirus(HMPV) infection is one of the leading causes of hospitalization in young children with acute respiratory illness. In this study, we prospectively collected respiratory tract samples from children who were hospitalized with acute lower respiratory tract infection in six hospitals in China from 2017 to 2019. HMPV was detected in 145 out of 2733 samples(5.3%) from the hospitalized children. The majority of HMPV-positive children were under the age of two(67.6%), with a median age of one year. HMPV can independently cause acute lower respiratory tract infection in young children, while all patients showed mild clinical symptoms. Of all the co-infected patients, HMPV was most commonly detected with enterovirus(EV) or rhinovirus(RhV)(38.0%),followed by respiratory syncytial virus(RSV)(32.0%). The highest detection rate occurred from March to May in both northern and southern China. Out of 145 HMPV positive samples, 48 were successfully typed, of which 36strains were subgrouped into subtypes A2c(75%), eight strains were included in subtype B1(16.7%), and four strains were included in subtype B2(8.3%). Moreover, 16 A2c strains contained 111-nucleotide duplications in the G gene. Twenty-seven complete HMPV genomes were successfully obtained, and 25(92.6%) strains belonged to subtype A2c, whereas one strain was included in subgroup B1 and another was included in subgroup B2. A total of 277 mutations were observed in the complete genomes of 25 A2c strains. All results presented here improve our understanding of clinical characteristics and molecular epidemiology of HMPV infection in children.

A multi-center study on Molecular Epidemiology of Human Respiratory Syncytial Virus from Children with Acute Lower Respiratory Tract Infections in the Mainland of China between 2015 and 2019

Human respiratory syncytial virus(RSV) is a major pathogen of acute lower respiratory tract infection among young children. To investigate the prevalence and genetic characteristics of RSV in China, we performed a molecular epidemiological study during 2015–2019. A total of 964 RSV-positive specimens were identified from 5529 enrolled patients during a multi-center study. RSV subgroup A(RSV-A) was the predominant subgroup during this research period except in2016. Totally, 535 sequences of the second hypervariable region(HVR-2) of the G gene were obtained. Combined with182 Chinese sequences from GenBank, phylogenetic trees showed that 521 RSV-A sequences fell in genotypes ON1(512),NA1(6) and GA5(3), respectively;while 196 RSV-B sequences fell in BA9(193) and SAB4(3). ON1 and BA9 were the only genotypes after December 2015. Genotypes ON1 and BA9 can be separated into 10 and 7 lineages, respectively. The HVR-2 of genotype ON1 had six amino acid changes with a frequency more than 10%, while two substitutions H258 Q and H266 L were co-occurrences. The HVR-2 of genotype BA9 had nine amino acid substitutions with a frequency more than10%, while the sequences with T290 I and T312 I were all from 2018 to 2019. One N-glycosylation site at 237 was identified among ON1 sequences, while two N-glycosylation sites(296 and 310) were identified in the 60-nucleotide duplication region of BA9. To conclusion, ON1 and BA9 were the predominant genotypes in China during 2015–2019. For the genotypes ON1 and BA9, the G gene exhibited relatively high diversity and evolved continuously.

山东省聊城市某医院老年患者下呼吸道鲍曼不动杆菌感染菌株的药敏特点及预后危险因素分析

目的:分析山东省聊城市某医院老年患者下呼吸道鲍曼不动杆菌感染菌株的药敏特征,探讨预后影响因素,为临床早期干预及合理用药提供理论依据。方法:回顾性分析2020年7月-2022年12月聊城某医院182例鲍曼不动杆菌下呼吸道感染老年患者的临床资料,药敏试验采用自动化仪器检测法及纸片扩散法(Kirby-Bauer,K-B)检测,根据临床和实验室标准协会,(Clinical&Laboratory Standards Institute,CLSD)标准判读结果,采用WHONET5.6和SPSS23.0统计软件进行数据分析。结果:药敏试验结果显示鲍曼不动杆菌对常用抗生素耐药率高于40%,其中对喹诺酮类、三代头孢菌素、哌拉西林/他唑巴坦、头孢哌酮/舒巴坦、碳青霉烯类(美罗培南、亚胺培南)呈高度耐药,耐药率在67%~77%之间;对庆大霉素、复方磺胺甲唑的耐药率>60%;对头孢吡耐药率46.7%。未见对粘菌素耐药菌株。对四环素类耐药率低,其中对替加环素耐药率0.6%,对米诺环素耐药率29.1%。多重耐药菌占比73.6%。共有54名患者死亡(29.7%),单因素分析显示,住院时间≥15天、昏迷、气管插管≥5d、多重耐药菌感染及使用广谱抗生素有统计学意义(P<0.05)。多因素Logistic回归分析显示,气管插管≥5d、住院时间≥15天、使用广谱抗生素是患者死亡的独立危险因素(P<0.05)。结论:老年患者下呼吸道鲍曼不动杆菌感染菌株对喹诺酮类、三代头孢菌素、酶抑制剂、碳青霉烯等抗生素耐药率较高,临床需加强细菌耐药监测,合理使用抗生素,及时评估并早期干预,可改善预后,降低死亡率。