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 of respiratory syncytial virus infection among children hospitalized with acute lower respiratory tract infections in Southern India

BACKGROUND Respiratory syncytial virus(RSV) is a leading cause of lower respiratory infections among children.AIM To investigate the proportion of RSV and non-RSV respiratory viral infections among hospitalized children ≤ 5 years.METHODS Hospitalized children aged < 5 years, with a diagnosis of acute lower respiratory infections(ALRI), admitted between August 2011-August 2013, were included.Cases were defined as laboratory-confirmed RSV and non-RSV respiratory viruses by direct fluorescence assay from the nasopharyngeal wash.RESULTS Of 383 1-59 mo old children hospitalized with an acute lower respiratory infection, 33.9%(130/383) had evidence of viral infection, and RSV was detected in 24.5%(94/383). Co-infections with RSV and other respiratory viruses(influenza A or B, adenovirus, para influenza 1, 2 or 3) were seen in children 5.5%(21/383). Over 90% of the RSV-positive children were under 2 years of age. RSV was detected throughout the year with peaks seen after the monsoon season.Children hospitalized with RSV infection were more likely to have been exposed to a shorter duration of breastfeeding of less than 3 mo. RSV positive children had a shorter hospital stay, although there were significant complications requiring intensive care. Use of antibiotics was high among those with RSV and non-RSV viral infections.CONCLUSION Our study provides evidence of a high proportion of RSV and other virusassociated ALRI among hospitalized children in India. RSV infection was associated with fewer days of hospital stay compared to other causes of lower respiratory infections. A high level of antibiotic use was seen among all respiratory virus-associated hospitalizations. These results suggest the need for implementing routine diagnostics for respiratory pathogens in order to minimize the use of unnecessary antibiotics and plan prevention strategies among pediatric populations.

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.

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.

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.

Effectiveness and Safety of Jinye Baidu Granules(金叶败毒颗粒)for Acute Upper Respiratory Tract Infection:A Systematic Review and Meta-analysis

To evaluate the effectiveness and safety of Jinye Baidu Granules(金叶败毒颗粒)for acute upper respiratory tract infection(AURTI).Database such as CNKI,Wan-fang,VIP,Sino Med,Web of science,Clinical Trials gov,Medline、EMBASE,CENTRAL,Cochrane Library were retrieved to collect randomized controlled trials(RCTs)on Jinye Baidu Granules(金叶败毒颗粒)in treating AURTI from the estabslishment of the database to March 2019.A total of 2 reviewers independently screened the literature according to the inclusion and exclusion criteria,and extracted material and the quality evaluation of the included studies.Quality evaluation adopted Cochrane Handbook 5.1 evaluation standards and tools.Rev Man5.3 was used to perform Meta-analysis for the adopted study.Finally a total of 4 RCTs involving 636 patients were included.Meta-analysis results showed that:compared with conventional Western medicine alone,Jinye Baidu Granules(金叶败毒颗粒)combined with Western medicine in the treatment of acute upper respiratory tract infection can improve the total effective rate of clinical efficacy[RR=0.13,95%CI(0.06,0.29),P<0.00001],shorten the time of antipyretic time for acute upper respiratory tract infection[MD=–1.22,95%CI(–1.43,–1.00),P<0.00001],shorten the time of pharyngeal pain[MD=–1.97,95%CI(–2.97,–0.96),P<0.0001]and shorten the cough disappear time[MD=–1.97,95%CI(–2.97,–0.96),P<0.0001].There were 2 papers reporting adverse reactions during the study period,and one of them specifically reported diarrhea,nausea,vomiting and stomachache in the experimental group.In the control group:diarrhea,nausea and adverse reactions disappeared after drug withdrawal;the incidence of adverse reactions was 3.92%in the control group and 5.88%in the observation group.There was no significant difference between the 2 groups(P>0.05).Based on existing data and methods,the systematic evaluation showed that,compared with Western medicine alone,Jinye Baidu Granules(金叶败毒颗粒)combined with Western medicine alone could improve the total effective rate of clinical efficacy,reduce the time of fever,sore throat,and the disappearance of cough with less adverse reactions.However,due to the low quality of the included study,large samples,multicenter,randomized,double-blind trials and trials are still needed to randomized controlled trials with reference to the CONSORT standard and the STRICTA statement.

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

Impact of Training of Dispensers on Case Management of Acute Respiratory Tract Infections at Community Pharmacies in Pakistan

Purpose: To evaluate the impact of training of dispensers on the process of case management of ARI at community pharmacies in context to history taking and provision of advice working at community pharmacies in Islamabad, Pakistan. Method: A randomized, controlled, blinded intervention study was designed and implemented. Before the implementation of intervention, a baseline study was performed to assess the process of case management for ARI at community pharmacies. The study population included all community pharmacy outlets in Islamabad. After data collection, data was analyzed. The result of the study revealed that the overall process of disease management of ARI at community pharmacies in Pakistan is not satisfactory. Pharmacies of Islamabad which were visited in pre intervention phase (118) were divided into two geographical regions A (intervention) and B (control). From which thirty pharmacies were selected randomly from each region. The targeted group of the interventions was drug sellers. Keeping in view the results of the base line study an educational intervention was designed to improve the case management of ARI at community pharmacies in Pakistan. Results: No significant difference (p ≤ 0.05) was seen in the process of history taking and advice provision in case of ARI management at community pharmacies between pre and post control groups. On the other hand significant difference in the process of history taking and provision of advice for ARI was observed in the intervention group before and after training. Conclusion: The study has highlighted that improvements in the current dispensing practices at community pharmacies are possible through appropriate educational interventions. The dispensers have the potential to provide fast and low cost healthcare to the masses in the country where the presence of doctors and qualified pharmacist is low;to date they are an untapped and underutilized source in the country.

Meta-analysis of the comparison between reduning injection and ribavirin injection for acute upper respiratory tract infection in children

Objective:To systematically evaluate the effectiveness and safety of reduning injection in acute upper respiratory tract infection of children.Methods:Use computer to search PubMed,the Cochrane Library,EMBASE,Web of Science,China National Knowledge Infrastructure(CNKI),Wanfang Database,Weipu database(VIP)and China Biomedical studies Service System(CBM)for randomized controlled trials(RCT)of acute upper respiratory tract infection in children,and the retrieval time is from their establishment to May,2022.After two researchers independently screened the studies,extracted data and evaluated the risk bias of studies,RevMan5.3 software was used to perform meta-analysis.Results:10 studies in total were included,involving 1466 patients.Results of the meta-analysis:total effective rate[RR=1.12,95%CI(1.07,1.16),P<0.00001],cure time[MD=-1.51,95%CI(-1.71,-1.32),P<0.00001],antipyretic time[MD=-1.32,95%CI(-1.72,-0.92),P<0.00001],disappearing time of nasal obstruction and nose running[MD=-1.04,95%CI(-1.45,-0.62),P<0.00001],disappearing time of cough[MD=-1.35,95%CI(-1.58,-1.13),P<0.00001],disappearing time of throat congestion[MD=-1.36,95%CI(-1.68,-1.03),P<0.00001],disappearing time of sore throat[MD=-1.55,95%CI(-1.74,-1.35),P<0.00001],the incidence of adverse reactions[RR=0.34,95%CI(0.20,0.57),P<0.0001].The differences between two groups in total effective rate,cure time,antipyretic time,disappearing time of nasal obstruction and nose running,disappearing time of cough,disappearing time of throat congestion,disappearing time of sore throat and the incidence of adverse reactions are all statistically significant(P<0.05).The sensitivity analysis demonstrates that three outcomes(total effective rate,cure time and disappearing time of sore throat)have unstable results,while others having stable results.Conclusion:Reduning injection is more effective than ribavirin injection in clinical,and it is better than ribavirin injection at relieving fever,nasal obstruction and nose running,cough and throat congestion.In addition,it’s safer in clinical than ribavirin injection.

ACUPUNCTURE TREATMENT OF 42 CASES OF ACUTE UPPER RESPIRATORY TRACT INFECTION

We made clinical observations on the therapeutic effect of acupuncture on acute upper respiratory tract infection and compared with the effect of paracetamol and Antondine, The result showed that acupuncture therapy could allay fever more rapidly than drugs, so long as the differentiation of syndromes is correct and the acupoint is selected properly.

The Effect of Comfort Nursing on the Compliance and Efficacy of Treatment for Children with Acute Otitis Media Caused by Upper Respiratory Tract Infection

Objective:To explore and analyze the clinical effect of comfort nursing on children with acute otitis media.Methods:62 children with acute otitis media caused by upper respiratory tract infection who visited the outpatient clinic of our hospital from June 2022 to June 2023 were selected for this study.They were divided into a study group(n=31)and a control group(n=31).Children in the control group received basic care,while children in the study group received comfort nursing along with basic care.The hearing thresholds,body temperature,treatment compliance,and nursing satisfaction of the two groups of children were compared.Results:After the nursing intervention,the hearing threshold and average body temperature of the children in the study group were lower than those in the control group(P<0.05);the treatment compliance of the children in the study group was higher than that in the control group(P<0.05);the nursing satisfaction of the study group was higher than that of the control group(P<0.05).Conclusion:Comfort nursing can improve the treatment effect,treatment compliance,and nursing satisfaction of children with children with acute otitis media caused by upper respiratory tract infection.

Association Between Diurnal Temperature Range and Respiratory Tract Infections

Objective This study aimed to assess the association between emergency-room visits for respiratory tract infection （RTI） with diurnal temperature range （DTR）, a weather parameter closely associated with urbanization and global climate change. Methods We conducted a semiparametric time-series analysis to estimate the percentage increase in emergency-room visits for RTI associated with changes in DTR after adjustment for daily weather conditions （temperature and relative humidity） and outdoor air pollution. Results DTR was significantly associated with daily emergency-room visits for RTI. An increase of 1 ~C in the current-day （LO） and in the 2-day moving average （L01） DTR corresponded to a 0.94% [95% confidence interval （CI）, 0.34%-1.55%] and 2.08% （95% CI, 1.24%-2.93%） increase in emergency-room visits for RTI, respectively. Conclusion DTR was associated with increased risk of RTI. More studies are needed to understand the impact of DTR on respiratory health.

Clinical Diagnosis and Treatment Characteristics of Acute Respiratory Infections in Children and New Developments in Laboratory Testing

Acute respiratory tract infection (ARTI) in children is the most common infectious disease in childhood, and its pathogens include viruses, bacteria and fungi, mycoplasma, chlamydia and rickettsia. In recent years, with the continuous development of pathogen detection methods, the diagnosis and treatment of acute respiratory infections has received more and more clinical attention. The clinical diagnosis and treatment characteristics of acute respiratory infections in children and the research of clinical laboratory detection methods have also been continuously developed. The author collected references to review the clinical features and new developments in laboratory testing of acute respiratory tract infection in children.

Influence of pidotimod combined with conventional drug therapy on the infection status and immune function of children with recurrent respiratory tract infection

Objective: To study the influence of pidotimod combined with conventional drug therapy on the infection status and immune function of children with recurrent respiratory tract infection. Methods: A total of 118 children with recurrent respiratory tract infection who were treated in the hospital between January 2015 and January 2017 were collected and divided into control group and observation group by random number table method, 59 cases in each group. Control group received conventional therapy, and observation group received pidotimod combined with conventional therapy. The differences in serum levels of inflammatory mediators, acute phase proteins and Th1/Th2 cytokines were compared between the two groups before and after treatment. Results: Before treatment, the differences in serum levels of inflammatory mediators, acute phase proteins and Th1/Th2 cytokines were not statistically significant between the two groups. after 1 week of treatment, serum TNF-α, PCT, CRP, PAB, TRF and IL-4 contents of both groups of children were lower than those before treatment while IFN-γ contents as well as IFN-γ/ IL-4 levels were higher than those before treatment, and serum TNF-α, PCT, CRP, PAB, TRF and IL-4 contents of observation group were lower than those of control group while IFN-γ content as well as IFN-γ/ IL-4 level was higher than those of control group. Conclusion: Pidotimod combined with conventional drug therapy can effectively inhibit the infection status and optimize the Th1/Th2 cellular immune function of children with recurrent respiratory tract infection.

SARS-CoV-2 viral load in the upper respiratory tract and disease severity in COVID-19 patients

Due to the disease's broad clinical spectrum,it is currently unclear how to predict the future prognosis of patients at the time of diagnosis of coronavirus disease 2019(COVID-19).Real-time reverse transcription-polymerase chain reaction(RTPCR)is the gold standard molecular technique for diagnosing COVID-19.The number of amplification cycles necessary for the target genes to surpass a threshold level is represented by the RT-PCR cycle threshold(Ct)values.Ct values were thought to be an adequate proxy for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)viral load.A body of evidence suggests that SARS-CoV-2 viral load is a possible predictor of COVID-19 severity.The link between SARS-CoV-2 viral load and the likelihood of severe disease development in COVID-19 patients is not clearly elucidated.In this review,we describe the scientific data as well as the important findings from many clinical studies globally,emphasizing how viral load may be related to disease severity in COVID-19 patients.Most of the evidence points to the association of SARS-CoV-2 viral load and disease severity in these patients,and early anti-viral treatment will reduce the severe clinical outcomes.

Lung Function in Wheezing Infants after Acute Lower Respiratory Tract Infection and Its Association with Respiratory Outcome

Background： Wheezing is common in early childhood and remains an important health concern. The aim of this study was to assess the lung function of wheezing infants and to investigate the relationship between lung function and respiratory outcome. Methods： Infants 〈2 years of age with acute lower respiratory tract infection （ALRTI） who had undergone lung function tests were included in the study. They were assigned to wheeze or no wheeze group based on physical examination. Infants without any respiratory diseases were enrolled as controls. Lung function was measured during the acute phase and 3 months after ALRTI. One-year follow-up for infants with ALRTI was achieved. Results： A total of 252 infants with ALRTI who had acceptable data regarding tidal breathing were included in the final analysis. Compared with the control and the no wheeze groups, infants in the wheeze group had significantly decreased time to peak tidal expiratory flow as a percentage of total expiratory time （TPTEF/TE） （20.1 1 6.4% vs. 34.4 ± 6.2% and 26.4 ±8.3%, respectively, P 〈 0.0001） and significantly increased peak tidal expiratory flow （PTEF） （90.7 ± 26.3 ml/s vs. 79.3 ± 18.4 ml/s and 86.1 ± 28.0 ml/s, respectively, P 〈 0.01）, sReff and Reff. The infants in the wheeze group still had lower TPTEF/TE and volume to peak tidal expiratory flow as a percentage of total expiratory volume （VPTEF/VE） than the no wheeze infants 3 months after the ALRT1. Moreover, there was a significant inverse relationship between TPTEF/TE, VPTEF/VE, and the recurrence of wheezing and pneumonia. Conclusions： Impaired lung function was present in wheezing infants with ALRTI and the deficits persisted. In addition, the lower level of TPTEF/TE and VPTEF/VE was a risk factor for poor respiratory outcome.

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.