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Objective: We developed an in-house bioinformatics pipeline to improve the detection of respiratory pathogens in metagenomic sequencing data. This pipeline addresses the need for short-time analysis, high accuracy, scalability, and reproducibility in a high-performance computing environment., Results: We evaluated our pipeline using ninety synthetic metagenomes designed to simulate nasopharyngeal swab samples. The pipeline successfully identified 177 out of 204 respiratory pathogens present in the compositions, with an average processing time of approximately 4 min per sample (processing 1 million paired-end reads of 150 base pairs). For the estimation of all the 470 taxa included in the compositions, the pipeline demonstrated high accuracy, identifying 420 and achieving a correlation of 0.9 between their actual and predicted relative abundances. Among the identified taxa, 27 were significantly underestimated or overestimated, including only three clinically relevant pathogens. We also validated the pipeline by applying it to a clinical dataset from a study on metagenomic pathogen characterization in patients with acute respiratory infections and successfully identified all pathogens responsible for the diagnosed infections. These findings underscore the pipeline's effectiveness in pathogen detection and highlight its potential utility in respiratory pathogen surveillance., (© 2024. The Author(s).)

Respiratory pathogens infecting the human respiratory system are characterized by their diversity, high infectivity, rapid transmission, and acute onset. Traditional detection methods are time-consuming, have low sensitivity, and lack specificity, failing to meet the needs of rapid clinical diagnosis. Nucleic acid aptamers, as an emerging and innovative detection technology, offer novel solutions with high specificity, affinity, and broad target applicability, making them particularly promising for respiratory pathogen detection. This review highlights the progress in the research and application of nucleic acid aptamers for detecting respiratory pathogens, discussing their selection, application, potential in clinical diagnosis, and future development. Notably, these aptamers can significantly enhance the sensitivity and specificity of detection when combined with detection techniques such as fluorescence, colorimetry and electrochemistry. This review offers new insights into how aptamers can address the limitations of traditional diagnostic methods and advance clinical diagnostics. It also highlights key challenges and future research directions for the clinical application of nucleic acid aptamers., (© 2024. The Author(s).)

Background: Accurate identification of the etiology of lower respiratory tract infections (LRTI) is crucial, particularly for immunocompromised patients with more complex etiologies. The advent of next-generation sequencing (NGS) has enhanced the effectiveness of pathogen detection. However, assessments of the clinical diagnostic value of targeted NGS (tNGS) in immunocompromised patients with LRTI are limited., Methods: To evaluate the diagnostic value of tNGS in immunocompromised patients with LRTI, a total of 88 patients, of whom 54 were immunocompromised, were enrolled. These patients underwent tNGS testing of bronchoalveolar lavage fluid (BALF). Results from both metagenomic next-generation sequencing (mNGS) and conventional microbiological tests (CMT) were also available for all participants. The performance of tNGS was assessed by comparing its findings against mNGS, CMT, and the clinical composite diagnosis., Results: In the cohort of 88 patients, tNGS showed comparable diagnostic value to mNGS and was significantly superior to CMT. Compared to CMT and composite reference standard, tNGS showed sensitivity of 94.55% and 90.48%, respectively. In immunocompromised patients, despite a more diverse pathogen variety, tNGS maintained similar sensitivity to mNGS and outperformed CMT. tNGS positively influenced etiologic diagnosis and antibiotic decision-making in 72.72% of cases, leading to a change in antibiotic regimen in 17.05% of cases. We also compared the detection of microbial nucleic acids by tNGS with mNGS and found that tNGS could identify 87.99% of the microbial nucleic acids identified by mNGS., Conclusion: In summary, our study demonstrated that tNGS offers promising clinical diagnostic accuracy in immunocompromised patients, as evidenced by its favorable comparison with CMT, the composite reference standard, and mNGS., (© 2024. The Author(s).)

Objective: Pulmonary infection is one of the leading causes of death in patients with ANCA-associated vasculitis (AAV). It is sometimes difficult to differentiate pulmonary infection from pulmonary involvement of vasculitis in AAV patients. Fiberoptic bronchoscopy and bronchoalveolar lavage fluid (BALF) assays are useful diagnostic methods. In addition to conventional microbiological tests (CMTs), metagenomic next-generation sequencing (mNGS) facilitates rapid and sensitive detection of various pathogens. The current study aimed to evaluate the advantages of additional BALF mNGS in the management of pulmonary infection in AAV patients., Methods: 27 patients with active AAV and suspected pulmonary infection whose BALF samples were tested by mNGS and CMTs and 17 active AAV patients whose BALF were tested by CMTs alone were retrospectively recruited. The results of microbiological tests, and adjustments of treatment following BALF mNGS, were described. The durations of antimicrobial treatment and in-hospital mortality in patients were compared., Results: Among the 27 patients whose BALF samples were tested by mNGS, 25.9% of patients did not have evidence of pathogenic microorganism in their BALF samples, 55.6% had polymicrobial infections, including bacteria, fungi and viruses. Of these 27 patients, 40.7% did not have evidence of pathogenic microorganism in their BALF or serum samples according to CMTs. Patients in the BALF mNGS/CMT group received a significantly shorter duration of antibacterial and total antimicrobial treatment than patients in the CMT alone group (17.3 ± 14.7 vs. 27.9 ± 19.0 days, P = 0.044; 18.9 ± 15.0 vs. 29.5 ± 17.7 days, P = 0.040, respectively). Fewer patients in the BALF mNGS/CMT group died than in the CMT alone group (4/27 vs. 7/17, P = 0.049)., Conclusion: Compared with CMT alone, additional mNGS tests may shorten the duration of antimicrobial treatment and possibly decrease death from severe infection by providing precise and quick diagnosis of infection., (© 2024. The Author(s).)

Background: Pentraxin 3 (PTX3) is an acute-phase reactant that is elevated in the plasma during inflammatory responses. We aimed to evaluate the utility of PTX3 as a clinical marker in children with lower respiratory tract infections (LRTIs) and the association between PTX3 and LRTIs severity., Methods: We included 60 patients admitted to Fayoum University Hospital with LRTIs fulfilling the WHO criteria for diagnosing LRTIs. We collected data on peak temperature, respiratory rate, heart rate, oxygen saturation upon admission, and length of hospital stay. The complete blood count (CBC), C-reactive protein (CRP) level, and PTX3 were measured upon admission., Results: PTX3 levels were significantly correlated with peak temperature, duration of hospital stay, the Pediatric Respiratory Severity Score (PRESS), total leucocytic count (TLC), CRP, and blood cultures., Conclusion: PTX-3 represented the severity of the disease and predicted the prognosis. Pentraxin levels demonstrate a statistically significant sensitivity of (93.3%) and a specificity of (70%) at the cut-off value (of 8.84) with an area under the curve (90.7%) in the diagnosis of LRTIs., (© 2024. The Author(s).)

Influenza-like illness (ILI) patients co-detected with respiratory pathogens exhibit poorer health outcomes than those with single infections. To address the paucity of knowledge concerning the incidence of concurrent respiratory pathogens, their relationships, and the clinical differences between patients detected with single and multiple pathogens, we performed an in-depth characterization of the oropharyngeal samples of primary care patients collected in Genoa (Northwest Italy), during winter seasons 2018/19-2019/20.The apriori algorithm was employed to evaluate the incidence of viral, bacterial, and viral-bacterial pairs during the study period. The grade of correlation between pathogens was investigated using the Phi coefficient. Factors associated with viral, bacterial or viral-bacterial co-detection were assessed using logistic regression.The most frequently identified pathogens included influenza A, rhinovirus, Haemophilus influenzae and Streptococcus pneumoniae. The highest correlations were found between bacterial-bacterial and viral-bacterial pairs, such as Haemophilus influenzae-Streptococcus pneumoniae, adenovirus-Haemophilus influenzae, adenovirus-Streptococcus pneumoniae, RSV-A-Bordetella pertussis, and influenza B Victoria-Bordetella parapertussis. Viruses were detected together at significantly lower rates. Notably, rhinovirus, influenza, and RSV exhibited significant negative correlations with each other. Co-detection was more prevalent in children aged < 4, and cough was shown to be a reliable indicator of viral co-detection.Given the evolving epidemiological landscape following the COVID-19 pandemic, future research utilizing the methodology described here, while considering the circulation of SARS-CoV-2, could further enrich the understanding of concurrent respiratory pathogens., (© 2024. The Author(s).)

Background: In this study, we aimed to evaluate the clinical utility of Metagenomic Next-Generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) in diagnosis of Lower Respiratory Tract Infections (LRTIs)., Methods: In this study, we retrospectively analyzed 186 hospitalized patients who were suspected with LRTIs and performed mNGS (DNA) test of BALF simultaneously at The Fifth Affiliated Hospital of Sun Yat-Sen University from March 2023 to August 2023. Suspected LRTI was based on LRTI related clinical manifestations or imaging examination. Among them, 155 patients had undergone conventional culture and mNGS (DNA) testing simultaneously. Finally, 138 cases (89.03%,138/155) were diagnosed as LRTI and 17 cases (10.97%,17/155) were diagnosed as non-LRTI. Both detecting rate and diagnostic efficacy of mNGS and conventional culture were compared., Results: The positive detection rates of pathogens between mNGS and conventional culture were significant different (81.29% VS 39.35%, P < 0.05). Compared with paired conventional culture result, the sensitivity of mNGS in diagnosis of LRTIs was more superior (88.41% VS 43.48%; P < 0.05), the specificity was opposite (76.47% VS 94.12%; P > 0.05). Furthermore, 77.54% and 35.51% of LRTI cases were being etiologically diagnosed by mNGS and culture respectively. Importantly, mNGS directly led to a change of treatment regimen in 58 (37.42%) cases, including antibiotic adjustment (29.68%) and ruling out active infection (7.74%). Moreover, treatment regimen remained unchanged in 97 (62.58%) cases, considering the current antibiotic therapy already covered the detected pathogens (36.13%) or empirical treatment was effective (11.61%)., Conclusions: mNGS can identify a wide range of pathogens in LRTIs, with improved sensitivity and being more superior at diagnosing LRTIs etiologically. mNGS has the potential to enhance clinical outcomes by optimizing the treatment regimens., (© 2024. The Author(s).)

Background: The rapid transmission and high pathogenicity of respiratory viruses significantly impact the health of both children and adults. Extracting and detecting their nucleic acid is crucial for disease prevention and treatment strategies. However, current extraction methods are laborious and time-consuming and show significant variations in nucleic acid content and purity among different kits, affecting detection sensitivity and efficiency. Our aim is to develop a novel method that reduces extraction time, simplifies operational steps, and ensures high-quality acquisition of respiratory viral nucleic acid., Methods: We extracted respiratory syncytial virus (RSV) nucleic acid using reagents with different components and analyzed cycle threshold (Ct) values via quantitative real-time polymerase chain reaction (qRT-PCR) to optimize and validate the novel lysis and washing solution. The performance of this method was compared against magnetic bead, spin column, and precipitation methods for extracting nucleic acid from various respiratory viruses. The clinical utility of this method was confirmed by comparing it to the standard magnetic bead method for extracting clinical specimens of influenza A virus (IAV)., Results: The solution, composed of equal parts glycerin and ethanol (50% each), offers an innovative washing approach that achieved comparable efficacy to conventional methods in a single abbreviated cycle. When combined with our A Plus lysis solution, our novel five-minute nucleic acid extraction (FME) method for respiratory viruses yielded superior RNA concentrations and purity compared to traditional methods. FME, when used with a universal automatic nucleic acid extractor, demonstrated similar efficiency as various conventional methods in analyzing diverse concentrations of respiratory viruses. In detecting respiratory specimens from 525 patients suspected of IAV infection, the FME method showed an equivalent detection rate to the standard magnetic bead method, with a total coincidence rate of 95.43% and a kappa statistic of 0.901 (P < 0.001)., Conclusions: The FME developed in this study enables the rapid and efficient extraction of nucleic acid from respiratory samples, laying a crucial foundation for the implementation of expedited molecular diagnosis., (© 2024. The Author(s).)

Background: The burden and characteristics of respiratory viral infections in children hospitalized for acute respiratory tract infections (ARTIs) during the post-COVID-19 pandemic era are unclear. We analyzed the epidemiological and clinical characteristics of pediatric patients hospitalized with common respiratory virus infections before and after relaxation of non-pharmaceutical interventions in Hangzhou, China and evaluated the diagnostic value of the six-panel respiratory pathogen detection system., Methods: Six types of respiratory viruses were detected in respiratory samples from children with suspected ARTIs by multiplex real-time quantitative polymerase chain reaction (RT-qPCR). Changes in virus detection rates and epidemiological and clinical characteristics, obtained from electronic health records, were analyzed. Binary logistic regression was used to identify respiratory tract infections risk factors. Multiplex RT-qPCR and targeted next-generation sequencing results were compared in random samples., Results: Among the 11,056 pediatric samples, 3228 tested positive for one or more of six common respiratory pathogens. RSV and PIV-3 detection rates differed significantly across age groups (both P < 0.001), and were more common in younger children. PIV-1 was more common in infants, toddlers, and preschoolers than in school-age children (P < 0.001). FluB was predominantly detected in school-age children (P < 0.001). RSV-, ADV-, and PIV-1-positivity rates were higher in 2022 than in 2023. Seasonal viral patterns differed across years. RSV (OR 9.156. 95% CI 5.905-14.195) and PIV-3 (OR 1.683, 95% CI 1.133-2.501) were risk factors for lower respiratory tract infections. RSV-positivity was associated with severe pneumonia (P = 0.044). PIV-3 (OR 0.391, 95% CI 0.170-0.899), summer season (OR 1.982, 95% CI 1.117-3.519), and younger age (OR 0.938, 95% CI 0.893-0.986) influenced pneumonia severity. Multiplex RT-qPCR showed good diagnostic performance., Conclusion: After changes in COVID-19 prevention and control strategies, six common respiratory viruses in children were prevalent in 2022-2023, with different seasonal epidemic characteristics and age proclivities. RSV and PIV-3 cause lower, and FluA, FluB, and ADV more typically cause upper respiratory tract infections. Infancy and summer season influence severe pneumonia risk. Multiplex RT-qPCR is valuable for accurate and timely detection of respiratory viruses in children, which facilitates management, treatment, and prevention of ARTIs., (© 2024. The Author(s).)

Background: Pulmonary exacerbations (PExs) in people with cystic fibrosis (PwCF) are associated with increased healthcare costs, decreased quality of life and the risk for permanent decline in lung function. Symptom burden, the continuous physiological and emotional symptoms on an individual related to their disease, may be a useful tool for monitoring PwCF during a PEx, and identifying individuals at high risk for permanent decline in lung function. The purpose of this study was to investigate if the degree of symptom burden severity, measured by the Cystic Fibrosis Respiratory Symptom Diary (CFRSD)- Chronic Respiratory Infection Symptom Scale (CRISS), at the onset of a PEx can predict failure to return to baseline lung function by the end of treatment., Methods: A secondary analysis of a longitudinal, observational study (N = 56) was conducted. Data was collected at four time points: year-prior-to-enrollment annual appointment, termed "baseline", day 1 of PEx diagnosis, termed "Visit 1", day 10-21 of PEx diagnosis, termed "Visit 2" and two-weeks post-hospitalization, termed "Visit 3". A linear regression model was performed to analyze the research question., Results: A regression model predicted that recovery of lung function decreased by 0.2 points for every increase in CRISS points, indicating that participants with a CRISS score greater than 48.3 were at 14% greater risk of not recovering to baseline lung function by Visit 2, than people with lower scores., Conclusion: Monitoring CRISS scores in PwCF is an efficient, reliable, non-invasive way to determine a person's status at the beginning of a PEx. The results presented in this paper support the usefulness of studying symptoms in the context of PEx in PwCF., (© 2024. The Author(s).)

Objectives: The performance of the new Respiratory Pathogen panel (fluorescent probe melting curve, FPMC) for the qualitative detection of 12 organisms (chlamydia pneumoniae, mycoplasma pneumoniae, adenovirus, influenza A virus, influenza B virus, parainfluenza virus, rhinovirus, etc.) was assessed., Methods: Prospectively collected nasopharyngeal swab (NPS) and sputum specimens (n = 635) were detected by using the FPMC panel, with the Sanger sequencing method as the comparative method., Results: The overall percent concordance between the FPMC analysis method and the Sanger sequencing method was 100% and 99.66% for NPS and sputum specimens, respectively. The FPMC testified an overall positive percent concordance of 100% for both NPS and sputum specimens. The FPMC analysis method also testified an overall negative percent concordance of 100% and 99.38% for NPS and sputum specimens, respectively., Conclusions: The FPMC analysis method is a stable and accurate assay for rapid, comprehensive detecting for respiratory pathogens., (© 2024. The Author(s).)

Objective: To investigate the association between meteorological data three days before admission and the status of sputum pathogens culture in hospitalized patients with Acute exacerbation of Chronic obstructive pulmonary disease (AECOPD) and respiratory infections., Methods: Data from 1,370 AECOPD patients (80.66% males, approximately 80% age > 70) with respiratory infections hospitalized in Fujian Provincial Hospital between December 2013 and December 2019 were collected. This cohort comprised, along with concurrent meteorological data from Fuzhou. Group differences were analyzed to compare the meteorological data three days prior to admission between patients with positive sputum pathogen cultures and those without. Logistic regression models were employed to investigate the association between meteorological parameters and the status of sputum pathogen cultures in patients with AECOPD and respiratory infections. Sensitivity analyses was conducted among the hospitalized patients from 2013 to 2016 and 2017-2019. Stratified analysis was performed to explore the factors affecting the effect of temperature differences and their interactions., Results: 578(42.19%) cases had a positive sputum culture report indicating pathogen growth. 323 cases were found with Gram-negative bacteria, 160 with Gram-positive bacteria, and 114 with fungi. Uni-variate analysis revealed statistical differences in DTD three days prior to admission (DTD-3d) between the positive and negative sputum culture groups (p = 0.019). Multivariate analysis indicated that an increase in the risk of positive sputum pathogen cultures was associated with greater DTD three days before admission (DTD-3d), with OR1.657 (95%CI [ 1.328-1.981]). The risk of positive sputum pathogen cultures was higher in groups with greater DTD-3d. The findings were consistent across different admission periods. Stratified analysis showed that patients without respiratory failure were more affected by DTD-3d, and an interaction effect was observed (p < 0.001)., Conclusion: In coastal areas, the diurnal temperature difference three days prior to admission affects the sputum pathogen status in AECOPD patients with respiratory infections., (© 2024. The Author(s).)

Background: Although administrative claims data have a high degree of completeness, not all medically attended Respiratory Syncytial Virus-associated lower respiratory tract infections (RSV-LRTIs) are tested or coded for their causative agent. We sought to determine the attribution of RSV to LRTI in claims data via modeling of temporal changes in LRTI rates against surveillance data., Methods: We estimated the weekly incidence of LRTI (inpatient, outpatient, and total) for children 0-4 years using 2011-2019 commercial insurance claims, stratified by HHS region, matched to the corresponding weekly NREVSS RSV and influenza positivity data for each region, and modelled against RSV, influenza positivity rates, and harmonic functions of time assuming negative binomial distribution. LRTI events attributable to RSV were estimated as predicted events from the full model minus predicted events with RSV positivity rate set to 0., Results: Approximately 42% of predicted RSV cases were coded in claims data. Across all regions, the percentage of LRTI attributable to RSV were 15-43%, 10-31%, and 10-31% of inpatient, outpatient, and combined settings, respectively. However, when compared to coded inpatient RSV-LRTI, 9 of 10 regions had improbable corrected inpatient LRTI estimates (predicted RSV/coded RSV ratio < 1). Sensitivity analysis based on separate models for PCR and antigen-based positivity showed similar results., Conclusions: Underestimation based on coding in claims data may be addressed by NREVSS-based adjustment of claims-based RSV incidence. However, where setting-specific positivity rates is unavailable, we recommend modeling across settings to mirror NREVSS's positivity rates which are similarly aggregated, to avoid inaccurate adjustments., (© 2024. The Author(s).)

Background: Lower Respiratory Tract Infections (LRTI) pose a serious threat to older adults but may be underdiagnosed due to atypical presentations. Here we assess LRTI symptom profiles and syndromic (symptom-based) case ascertainment in older (≥ 65y) as compared to younger adults (< 65y)., Methods: We included adults (≥ 18y) with confirmed LRTI admitted to two acute care Trusts in Bristol, UK from 1st August 2020- 31st July 2022. Logistic regression was used to assess whether age ≥ 65y reduced the probability of meeting syndromic LRTI case definitions, using patients' symptoms at admission. We also calculated relative symptom frequencies (log-odds ratios) and evaluated how symptoms were clustered across different age groups., Results: Of 17,620 clinically confirmed LRTI cases, 8,487 (48.1%) had symptoms meeting the case definition. Compared to those not meeting the definition these cases were younger, had less severe illness and were less likely to have received a SARS-CoV-2 vaccination or to have active SARS-CoV-2 infection. Prevalence of dementia/cognitive impairment and levels of comorbidity were lower in this group. After controlling for sex, dementia and comorbidities, age ≥ 65y significantly reduced the probability of meeting the case definition (aOR = 0.67, 95% CI:0.63-0.71). Cases aged ≥ 65y were less likely to present with fever and LRTI-specific symptoms (e.g., pleurisy, sputum) than younger cases, and those aged ≥ 85y were characterised by lack of cough but frequent confusion and falls., Conclusions: LRTI symptom profiles changed considerably with age in this hospitalised cohort. Standard screening protocols may fail to detect older and frailer cases of LRTI based on their symptoms., (© 2024. The Author(s).)

Background: Effects of non-pharmaceutical interventions during the pandemic were mainly studied for severe outcomes. Among children, most of the burden of respiratory infections is related to infections which are not medically attended. The perspective on infections in the community setting is necessary to understand the effects of the pandemic on non-pharmaceutical interventions., Methods: In the unique prospective LoewenKIDS cohort study, we compared the true monthly incidence of self-reported acute respiratory infections (ARI) in about 350 participants (aged 3-4 years old) between October 2019 to March 2020 (pre-pandemic period) and October 2020 to March 2021 (pandemic period). Parents reported children's symptoms using a diary. Parents were asked to take a nasal swab of their child during all respiratory symptoms. We analysed 718 swabs using Multiplex PCR for 25 common respiratory viruses and bacteria., Results: During the pre-pandemic period, on average 44.6% (95% CI: 39.5-49.8%) of children acquired at least one ARI per month compared to 19.9% (95% CI: 11.1-28.7%) during the pandemic period (Incidence Rate Ratio = 0.47; 95% CI: 0.41-0.54). The detection of influenza virus decreased absolute by 96%, respiratory syncytial virus by 65%, metapneumovirus by 95%, parainfluenza virus by 100%, human enterovirus by 96% and human bocavirus by 70% when comparing the pre-pandemic to the pandemic period. However, rhinoviruses were nearly unaffected by NPI. Co-detection (detection of more than one virus in a single symptomatic swab) was common in the pre-pandemic period (222 of 390 samples with viral detection; 56.9%) and substantially less common during the pandemic period (46 of 216 samples; 21.3%)., Conclusion: Non-pharmaceutical interventions strongly reduced the incidence of all respiratory infections in preschool children but did not affect rhinovirus., (© 2024. The Author(s).)

Objectives: This study aims to compare the diagnostic efficacy of metagenomic next-generation sequencing (mNGS) to traditional diagnostic methods in patients with lower respiratory tract infections (LRTIs), elucidate the etiological spectrum of these infections, and explore the impact of mNGS on guiding antimicrobial therapy., Methods: We retrospectively analyzed data from 128 patients admitted to the Respiratory Department of Anqing 116 Hospital between July 2022 and July 2023. All patients had undergone both mNGS and conventional microbiological techniques (CMT) for LRTI diagnosis. We assessed the diagnostic performance of these methods and examined the influence of mNGS on antimicrobial decision-making., Results: Overall, mNGS demonstrated superior sensitivity (96.8%) and accuracy (96.8%) compared to CMT. For Mycobacterium tuberculosis detection, the accuracy and sensitivity of mNGS was 88.8% and 77.6%, which was lower than the 94.7% sensitivity of the T-spot test and the 79.6% sensitivity of CMT. In fungal pathogen detection, mNGS showed excellent sensitivity (90.5%), specificity (86.7%), and accuracy (88.0%). Bacteria were the predominant pathogens detected (75.34%), with Mycobacterium tuberculosis (41.74%), Streptococcus pneumoniae (21.74%), and Haemophilus influenzae (16.52%) being most prevalent. Bacterial infections were most common (62.10%), followed by fungal and mixed infections (17.74%). Of the 118 patients whose treatment regimens were adjusted based on mNGS results, 102 (86.5%) improved, 7 (5.9%) did not respond favorably, and follow-up was lost for 9 patients (7.6%)., Conclusions: mNGS offers rapid and precise pathogen detection for patients with suspected LRTIs and shows considerable promise in diagnosing Mycobacterium tuberculosis and fungal infections. By broadening the pathogen spectrum and identifying polymicrobial infections, mNGS can significantly inform and refine antibiotic therapy., (© 2024. The Author(s).)

Background: A dearth of studies showed that infectious diseases cause the majority of deaths among under-five children. Worldwide, Acute Respiratory Infection (ARI) continues to be the second most frequent cause of illness and mortality among children under the age of five. The paramount disease burden in developing nations, including Ethiopia, is still ARI., Objective: This study aims to determine the magnitude and predictors of ARI among under-five children in Ethiopia using used state of the art machine learning algorithms., Methods: Data for this study were derived from the 2016 Ethiopian Demographic and Health Survey. To predict the determinants of acute respiratory infections, we performed several experiments on ten machine learning algorithms (random forests, decision trees, support vector machines, Naïve Bayes, and K-nearest neighbors, Lasso regression, GBoost, XGboost), including one classic logistic regression model and an ensemble of the best performing models. The prediction ability of each machine-learning model was assessed using receiver operating characteristic curves, precision-recall curves, and classification metrics., Results: The total ARI prevalence rate among 9501 under-five children in Ethiopia was 7.2%, according to the findings of the study. The overall performance of the ensemble model of SVM, GBoost, and XGBoost showed an improved performance in classifying ARI cases with an accuracy of 86%, a sensitivity of 84.6%, and an AUC-ROC of 0.87. The highest performing predictive model (the ensemble model) showed that the child's age, history of diarrhea, wealth index, type of toilet, mother's educational level, number of living children, mother's occupation, and type of fuel they used were an important predicting factor for acute respiratory infection among under-five children., Conclusion: The intricate web of factors contributing to ARI among under-five children was identified using an advanced machine learning algorithm. The child's age, history of diarrhea, wealth index, and type of toilet were among the top factors identified using the ensemble model that registered a performance of 86% accuracy. This study stands as a testament to the potential of advanced data-driven methodologies in unraveling the complexities of ARI in low-income settings., (© 2024. The Author(s).)

Background: Currently, culture methods are commonly used in clinical tests to detect pathogenic fungi including Candida spp. Nonetheless, these methods are cumbersome and time-consuming, thereby leading to considerable difficulties in diagnosis of pathogenic fungal infections, especially in situations that respiratory samples such as alveolar lavage fluid and pleural fluid contain extremely small amounts of microorganisms. The aim of this study was to elucidate the utility and practicality of microfluidic chip technology in quick detection of respiratory pathogenic fungi., Methods: DNAs of clinical samples (mainly derived from sputa, alveolar lavage fluid, and pleural fluid) from 64 coastal patients were quickly detected using microfluidic chip technology with 20 species of fungal spectrum and then validated by Real-time qPCR, and their clinical baseline data were analyzed., Results: Microfluidic chip results showed that 36 cases infected with Candida spp. and 27 cases tested negative for fungi, which was consistent with Real-time qPCR validation. In contrast, only 16 cases of fungal infections were detected by the culture method; however, one of the culture-positive samples tested negative by microfluidic chip and qPCR validation. Moreover, we found that the patients with Candida infections had significantly higher rates of platelet count reduction than fungi-negative controls. When compared with the patients infected with C. albicans alone, the proportion of males in the patients co-infected with multiple Candidas significantly increased, while their platelet counts significantly decreased., Conclusions: These findings suggest that constant temperature amplification-based microfluidic chip technology combined with routine blood tests can increase the detection speed and accuracy (including sensitivity and specificity) of identifying respiratory pathogenic fungi., (© 2024. The Author(s).)

Human metapneumovirus (HMPV) is a newly identified pathogen causing acute respiratory tract infections in young infants worldwide. Since the initial document of HMPV infection in China in 2003, Chinese scientists have made lots of efforts to prevent and control this disease, including developing diagnosis methods, vaccines and antiviral agents against HMPV, as well as conducting epidemiological investigations. However, effective vaccines or special antiviral agents against HMPV are currently not approved, thus developing early diagnosis methods and knowing its epidemiological characteristics will be beneficial for HMPV control. Here, we summarized current research focused on the epidemiological characteristics of HMPV in China and its available detection methods, which will be beneficial to increase the public awareness and disease control in the future., (© 2024. The Author(s).)

Background: Recurrent Upper Respiratory Tract Infections (R-URTIs) pose a significant challenge in pediatric healthcare, affecting both children and their families. This study aimed to investigate the prevalence, risk factors, and clinical implications of R-URTI in children aged 0-5 years., Methods: This observational study involved a sample of 483 children aged 0-5 years, focusing on establishing a practical and dynamic definition of R-URTI. Family pediatricians prospectively collected socio-demographic information, medical history, and recorded the occurrence of URTI episodes. Children were followed from recruitment until March 2021, predating the COVID-19 outbreak., Results: A substantial prevalence of R-URTIs was found, estimating it at 5-10% among this age group. To define R-URTI, a practical and dynamic criterion was proposed: children experiencing a minimum of four URTI episodes, each lasting four days or more, within a six-month period, with intervals of well-being in between., Conclusions: The study highlighted that specific risk factors for R-URTI were elusive, suggesting that this condition may affect children regardless of their family or clinical history. Moreover, the study's stratification by age group and times of observation facilitated patient-specific clinical decision-making. The proposed definition may represent a valuable tool for clinicians in diagnosing and addressing R-URTI cases., (© 2024. The Author(s).)

Background: Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Streptococcus pneumoniae and Staphylococcus aureus are major bacterial causes of lower respiratory tract infections (LRTIs) globally, leading to substantial morbidity and mortality. The rapid increase of antimicrobial resistance (AMR) in these pathogens poses significant challenges for their effective antibiotic therapy. In low-resourced settings, patients with LRTIs are prescribed antibiotics empirically while awaiting several days for culture results. Rapid pathogen and AMR gene detection could prompt optimal antibiotic use and improve outcomes., Methods: Here, we developed multiplex quantitative real-time PCR using EvaGreen dye and melting curve analysis to rapidly identify six major pathogens and fourteen AMR genes directly from respiratory samples. The reproducibility, linearity, limit of detection (LOD) of real-time PCR assays for pathogen detection were evaluated using DNA control mixes and spiked tracheal aspirate. The performance of RT-PCR assays was subsequently compared with the gold standard, conventional culture on 50 tracheal aspirate and sputum specimens of ICU patients., Results: The sensitivity of RT-PCR assays was 100% for K. pneumoniae, A. baumannii, P. aeruginosa, E. coli and 63.6% for S. aureus and the specificity ranged from 87.5% to 97.6%. The kappa correlation values of all pathogens between the two methods varied from 0.63 to 0.95. The limit of detection of target bacteria was 1600 CFU/ml. The quantitative results from the PCR assays demonstrated 100% concordance with quantitative culture of tracheal aspirates. Compared to culture, PCR assays exhibited higher sensitivity in detecting mixed infections and S. pneumoniae. There was a high level of concordance between the detection of AMR gene and AMR phenotype in single infections., Conclusions: Our multiplex quantitative RT-PCR assays are fast and simple, but sensitive and specific in detecting six bacterial pathogens of LRTIs and their antimicrobial resistance genes and should be further evaluated for clinical utility., (© 2024. The Author(s).)

Objective: This study aims to identify the most effective diagnostic method for distinguishing pathogenic and non-pathogenic Gram-negative bacteria (GNB) in suspected pneumonia cases using metagenomic next-generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) samples., Methods: The effectiveness of mNGS was assessed on BALF samples collected from 583 patients, and the results were compared with those from microbiological culture and final clinical diagnosis. Three interpretational approaches were evaluated for diagnostic accuracy., Results: mNGS outperformed culture significantly. Among the interpretational approaches, Clinical Interpretation (CI) demonstrated the best diagnostic performance with a sensitivity of 87.3%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 98.3%. CI's specificity was significantly higher than Simple Interpretation (SI) at 37.9%. Additionally, CI excluded some microorganisms identified as putative pathogens by SI, including Haemophilus parainfluenzae, Haemophilus parahaemolyticus, and Klebsiella aerogenes., Conclusion: Proper interpretation of mNGS data is crucial for accurately diagnosing respiratory infections caused by GNB. CI is recommended for this purpose., (© 2024. The Author(s).)

Background: Germline heterozygous gain-of-function (GOF) mutations in the PIK3CD gene lead to a rare primary immunodeficiency disease known as activated phosphoinositide 3-kinase (PI3K) δ syndrome type 1(APDS1). Affected patients present a spectrum of clinical manifestations, particularly recurrent respiratory infections and lymphoproliferation, increased levels of serum immunoglobulin (Ig) M, Epstein-Barr virus (EBV) and cytomegalovirus (CMV) viremia. Due to highly heterogeneous phenotypes of APDS1, it is very likely that suspected cases may be misdiagnosed., Methods: Herein we reported three patients with different clinical presentations but harboring pathogenic variants in PIK3CD gene detected by trio whole-exome sequencing (trio-WES) and confirmed by subsequent Sanger sequencing., Results: Two heterozygous mutations (c.3061G > A, p.E1021K and c.1574 A > G, p.E525G) in PIK3CD (NM&#95;005026.3) were identified by whole exome sequencing (WES) in the three patients. One of two patients with the mutation (c.3061G > A) presented with abdominal pain and diarrhea as the first symptoms, which was due to intussusception caused by multiple polyps of colon. The patient with mutation (c.1574 A > G) had an anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)-like clinical manifestations, including multisystemic inflammation, acute nephritic syndrome, and positive perinuclear ANCA (p-ANCA), thus the diagnosis of ANCA-AAV was considered., Conclusions: Our study expands the spectrums of clinical phenotype and genotype of APDS, and demonstrates that WES has a high molecular diagnostic yield for patients with immunodeficiency related symptoms, such as respiratory infections, multiple ecchymosis, ANCA-associated vasculitis, multiple ileocecal polyps, hepatosplenomegaly, and lymphoid hyperplasia., Trial Registration: Retrospectively registered., (© 2024. The Author(s).)

Background: Acute respiratory infections (ARIs) remain a major public health concern which become the leading cause of mortality and morbidity in children under the age of five. A large percentage of childhood deaths and complications can be avoided by seeking proper medical care. Therefore, this study aimed to assess the magnitude, and individual and community-level determinants of mothers' healthcare-seeking behavior for their children under the age of five who had ARI symptoms in Ethiopia., Method: A secondary data analysis was conducted using the 2016 Ethiopian Demographic and Health Surveys(EDHS) with a total weighted sample of 643 under-five children who had ARI symptoms within two weeks of the survey. Due to the hierarchical nature of the EDHS data, a multi-level logistic regression model was used to identify the individual and community-level factors influencing mothers' health care-seeking behavior for their children with ARI symptoms. In the multivariable multilevel analysis, those variables with a p-value < 0.05 were considered to be significant predictors of the outcome variable., Results: Healthcare-seeking behavior among mothers or caregivers for children with symptoms of ARIs was 32.61% (95% CI: 29.08-36.33%) in Ethiopia. The ICC in the null model indicated that about 55% of the total variability of treatment-seeking behavior was due to differences between clusters. Child aged > 24 months [AOR = 0.35; 0.19-0.63], having primary education [AOR = 3.25; 1.27-8.32], being media exposed [AOR = 2.49; 1.15, 5.38], female household head[AOR = 3.90; 1.35, 11.24], and delivery at health institution[AOR = 2.24; 1.00, 5.01] were significant predictors of health care seeking behavior of mother for their children with ARI symptoms., Conclusion: There is poor treatment-seeking behavior for children with symptoms of ARI in Ethiopia with significant community level variations. The multilevel logistic regression analysis showed that improving mothers' education, women's empowerment, facilitating institutional delivery and media accessibility are critical to promoting health-seeking behaviors among mothers or caregivers of under-five children with ARI symptoms. Hence, concerned bodies should design targeted interventions that increase mothers' or caregivers' treatment-seeking behavior for childhood ARI to reduce child morbidity and mortality., (© 2023. The Author(s).)

Objective: It is now understood that the Coronavirus disease 2019 (COVID-19) pandemic and its associated containment measures have influenced the epidemiology of other respiratory viruses. This study aimed to characterize respiratory virus infections in pediatric patients hospitalized for acute respiratory infections (ARIs) in East China both prior to and during the COVID-19 pandemic., Methods: We collected nasal secretions from 9782 pediatric ARI patients admitted to Shaoxing Maternal and Child Health Care Hospital between January 2018 and December 2022. We analyzed and compared changes in viral detection rates, epidemiological features, and clinical characteristics., Results: A total of 1633 strains from 7 common respiratory viruses were identified, with an overall positive rate of 16.35% (n = 821/5021) in 2018-2019 and 17.06% (n = 812/4761) in 2020-2022. Compared to 2018-2019, the positive rate for RSV significantly increased in 2020-2022, while detection rates for ADV, PIV-2, PIV-3, and flu-B showed reductions (P < 0.05). The RSV-positive rate experienced a more significant increase in winter compared to other seasons both before and during COVID-19 (P < 0.05), whereas PIV-3 predominantly circulated in spring and summer before COVID-19., Conclusion: During the COVID-19 pandemic, marked variations in age distribution and seasonality of respiratory virus infections were observed among hospitalized children with ARIs in East China. Non-pharmaceutical interventions (NPIs) implemented during the pandemic yielded a limited impact on common respiratory viruses., (© 2023. The Author(s).)

Background: For surveillance of episodic illness, the emergency department (ED) represents one of the largest interfaces for generalizable data about segments of the US public experiencing a need for unscheduled care. This protocol manuscript describes the development and operation of a national network linking symptom, clinical, laboratory and disposition data that provides a public database dedicated to the surveillance of acute respiratory infections (ARIs) in EDs., Methods: The Respiratory Virus Laboratory Emergency Department Network Surveillance (RESP-LENS) network includes 26 academic investigators, from 24 sites, with 91 hospitals, and the Centers for Disease Control and Prevention (CDC) to survey viral infections. All data originate from electronic medical records (EMRs) accessed by structured query language (SQL) coding. Each Tuesday, data are imported into the standard data form for ARI visits that occurred the prior week (termed the index file); outcomes at 30 days and ED volume are also recorded. Up to 325 data fields can be populated for each case. Data are transferred from sites into an encrypted Google Cloud Platform, then programmatically checked for compliance, parsed, and aggregated into a central database housed on a second cloud platform prior to transfer to CDC., Results: As of August, 2023, the network has reported data on over 870,000 ARI cases selected from approximately 5.2 million ED encounters. Post-contracting challenges to network execution have included local shifts in testing policies and platforms, delays in ICD-10 coding to detect ARI cases, and site-level personnel turnover. The network is addressing these challenges and is poised to begin streaming weekly data for dissemination., Conclusions: The RESP-LENS network provides a weekly updated database that is a public health resource to survey the epidemiology, viral causes, and outcomes of ED patients with acute respiratory infections., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Epstein-Barr virus (EBV) infection is likely to co-occur in pediatric respiratory tract infections (RTIs). Liver injury is the common complication of EBV infection. The detailed risk factors for liver injury in EBV infection remain elusive. We aimed to investigate the incidence, characteristics and potential risk factors for liver injury in EBV infection for early risk prediction., Methods: We retrospectively recruited the pediatric RTIs cases with EBV infection according to a predefined criteria from our hospital between January 2015 and December 2017. We extracted the clinical and laboratory data from the electronical medical records. The impact of age, gender, and various parameters on the liver injury risk was investigated. Univariate logistic regression analysis was performed to analyse the association between clinical/laboratory parameters and liver injury. The related indexes were enrolled in the multivariate logistic regression analysis. Decision curve analysis was used to yield the value of related parameters in predicting liver injury. Receiver operating curve (ROC) analysis was applied to produce the C-index of white blood cell (WBC) count for liver injury. We also tested the non-linear association between WBC count and alanine aminotransferase (ALT)., Results: A total of 216 pediatric RTIs with EBV infection were enrolled. EBV infection is more likely to occur during the winter season. Cytomegalovirus infection was independently associated with liver injury in EBV infection (OR = 6.972, 95% CI = 1.648-29.490, p = 0.008). WBC count was independently associated with liver injury in EBV infection (OR = 1.169, 95% CI = 1.051-1.301, p = 0.004). The P interaction value between WBC count and cytomegalovirus was 0.149. The decision curve analysis showed that WBC count had larger area under curve compared with platelet (PLT) and birthweight (BW). ROC analysis yielded the c-index of WBC count: 0.75 and cut-point of 8.3. The turning point of WBC count in its association with ALT was 16.8. The p value before and after the turning point was < 0.001 and 0.123, respectively., Conclusions: Cytomegalovirus co-infection demonstrated 5.972 more times of liver injury risk in EBV infection. WBC count was an independent biomarker for liver injury before the turning point of 16.8 in EBV infection. More attention should be paid to the risk of EBV infection in the winter. Cytomegalovirus infection and WBC count merit attention in the monitoring of possible liver injury in EBV infection among pediatric RTIs., (© 2023. Società Italiana di Pediatria.)

Background: Antibiotics are over-used for patients with respiratory tract infections (RTIs) in primary care, especially in the rural areas of China., Methods: A cluster randomized controlled trial (RCT) will be carried out to estimate the effectiveness of a tailored message package for educating patients to reduce antibiotic use for symptomatic respiratory tract infections (RTIs). In the intervention group, patients will receive 12 short messages in 12 consecutive days. The whole process of the message design, modification, translation (of substitution variables), and sending will be facilitated by a user-friendly mini-computer program. The primary measure for assessment is the reduction in number of days in which antibiotics are used by patients with symptomatic RTIs. The secondary measures include (1) patients' knowledge about and attitude toward antibiotics; (2) patients' quality of life (EQ-5D-5L) and symptom severity and duration; (3) times of re-visits to clinics and antibiotics re-prescription for the same RTI episode; and (4) times of re-occurrence of RTIs and related health service seeking and antibiotics consumption., Discussion: This study will determine the efficacy of a 12-message intervention to educate patients to reduce excessive antibiotic use in rural China., Trial Registration: ISRCTN29801086 . Registered on 23 September 2022., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Eosinophilic airway inflammation caused by respiratory virus infection has been demonstrated in basic research; however, clinical investigations are lacking. To clarify the extent to which respiratory virus infection induces airway eosinophilic inflammation, we reviewed the results of bronchoalveolar lavage (BAL) and respiratory virus testing performed at our hospital., Methods: Among the BAL procedures performed at the University of the Ryukyu Hospital from August 2012 to September 2016, we collected cases of acute respiratory disease in which multiplex polymerase chain reaction (PCR) was used to search for respiratory viruses. The effect of respiratory virus detection on BAL eosinophil fraction was analyzed using statistical analysis. A case study was conducted on respiratory virus detection, which showed an elevated BAL eosinophil fraction., Results: A total of 95 cases were included in this study, of which 17 were PCR-positive. The most common respiratory virus detected was parainfluenza virus (eight cases). The PCR-positive group showed a higher BAL eosinophil fraction than the PCR-negative group (p = 0.030), and more cases had a BAL eosinophil fraction > 3% (p = 0.017). Multivariate analysis revealed that being PCR-positive was significantly associated with BAL eosinophil fraction > 1% and > 3%. There were nine PCR-positive cases with a BAL eosinophil fraction > 1%, of which two cases with parainfluenza virus infection had a marked elevation of BAL eosinophil fraction and were diagnosed with eosinophilic pneumonia., Conclusions: Cases of viral infection of the lower respiratory tract showed an elevated BAL eosinophil fraction. The increase in eosinophil fraction due to respiratory virus infection was generally mild, whereas some cases showed marked elevation and were diagnosed with eosinophilic pneumonia. Respiratory virus infection is not a rare cause of elevated BAL eosinophil fraction and should be listed as a differential disease in the practice of eosinophilic pneumonia., (© 2023. The Author(s).)

Background: Respiratory symptoms are the earliest clinical manifestation of Talaromyces marneffei (TM) infection. In this study, we aimed to improve the early identification of TM infection in human immunodeficiency virus (HIV)-negative children with respiratory symptoms as the first manifestation, analyze the risk factors, and provide evidence for diagnosis and treatment., Methods: We retrospectively analyzed six cases of HIV-negative children with respiratory system infection symptoms as the first presentation., Results: All subjects (100%) had cough and hepatosplenomegaly, and five subjects (83.3%) had a fever; other symptoms and signs included lymph node enlargement, rash, rales, wheezing, hoarseness, hemoptysis, anemia, and thrush. Additionally, 66.7% of the cases had underlying diseases (three had malnutrition, one had severe combined immune deficiency [SCID]). The most common coinfecting pathogen was Pneumocystis jirovecii, which occurred in two cases (33.3%), followed by one case of Aspergillus sp. (16.6%). Furthermore, the value of β-D-glucan detection (G test) increased in 50% of the cases, while the proportion of NK decreased in six cases (100%). Five children (83.3%) were confirmed to have the pathogenic genetic mutations. Three children (50%) were treated with amphotericin B, voriconazole, and itraconazole, respectively; three children (50%) were treated with voriconazole and itraconazole. All children were tested for itraconazole and voriconazole plasma concentrations throughout antifungal therapy. Two cases (33.3%) relapsed after drug withdrawal within 1 year, and the average duration of antifungal treatment for all children was 17.7 months., Conclusion: The first manifestation of TM infection in children is respiratory symptoms, which are nonspecific and easily misdiagnosed. When the effectiveness of anti-infection treatment is poor for recurrent respiratory tract infections, we must consider the condition with an opportunistic pathogen and attempt to identify the pathogen using various samples and detection methods to confirm the diagnosis. It is recommended the course for anti-TM disease be longer than one year for children with immune deficiency. Monitoring the blood concentration of antifungal drugs is important., (© 2023. The Author(s).)

Background: Nasopharyngeal swabs are taken to determine the causative agent of community acquired pneumonia (CAP), while the reliability of upper respiratory tract sampling as a proxy for lower respiratory tract infections is still unclear., Methods: Nasopharyngeal (NP) swabs, bronchoalveolar lavage (BAL) fluid samples and clinical data were collected from 153 hospitalized children between 3 months and 14 years of age with severe CAP, enrolled from March to June 2019. Written informed consent for the storage and use of the samples for further studies was obtained from the parents or caregivers. Putative pathogens were detected using a sensitive, high-throughput GeXP-based multiplex PCR and qPCR., Results: The same bacterial species in paired samples were found in 29 (23.4%) and the same viral species in 52 (27.5%) of the patients. moderate concordance was found for Mycoplasma pneumoniae (ĸ=0.64), followed by Haemophilus influenzae (ĸ=0.42). The strongest discordance was observed for human adenovirus and also for Pseudomonas aeruginosa, the latter was exclusively detected in BAL samples. In the adenovirus cases strong concordance was associated with high viral loads in the NP swabs., Conclusion: The variation in concordance in pathogen detection in the upper and lower respiratory tract of children with severe pneumonia is generally high but varies depending on the species. Novel and impactful insights are the concordance between NP and BAL detection for M. pneumoniae and H. influenzae and the strong correlation between high adenoviral loads in NP swabs and detection in BAL fluid., (© 2023. The Author(s).)

Background: Rhinovirus (RV) is one of the most common etiologic agents of acute respiratory infection (ARI), which is a leading cause of morbidity and mortality in young children. The clinical significance of RV co-detection with other respiratory viruses, including respiratory syncytial virus (RSV), remains unclear. We aimed to compare the clinical characteristics and outcomes of children with ARI-associated RV-only detection and those with RV co-detection-with an emphasis on RV/RSV co-detection., Methods: We conducted a prospective viral surveillance study (11/2015-7/2016) in Nashville, Tennessee. Children < 18 years old who presented to the emergency department (ED) or were hospitalized with fever and/or respiratory symptoms of < 14 days duration were eligible if they resided in one of nine counties in Middle Tennessee. Demographics and clinical characteristics were collected by parental interviews and medical chart abstractions. Nasal and/or throat specimens were collected and tested for RV, RSV, metapneumovirus, adenovirus, parainfluenza 1-4, and influenza A-C using reverse transcription quantitative polymerase chain reaction assays. We compared the clinical characteristics and outcomes of children with RV-only detection and those with RV co-detection using Pearson's χ 2 test for categorical variables and the two-sample t-test with unequal variances for continuous variables., Results: Of 1250 children, 904 (72.3%) were virus-positive. RV was the most common virus (n = 406; 44.9%), followed by RSV (n = 207; 19.3%). Of 406 children with RV, 289 (71.2%) had RV-only detection, and 117 (28.8%) had RV co-detection. The most common virus co-detected with RV was RSV (n = 43; 36.8%). Children with RV co-detection were less likely than those with RV-only detection to be diagnosed with asthma or reactive airway disease both in the ED and in-hospital. We did not identify differences in hospitalization, intensive care unit admission, supplemental oxygen use, or length of stay between children with RV-only detection and those with RV co-detection., Conclusion: We found no evidence that RV co-detection was associated with poorer outcomes. However, the clinical significance of RV co-detection is heterogeneous and varies by virus pair and age group. Future studies of RV co-detection should incorporate analyses of RV/non-RV pairs and include age as a key covariate of RV contribution to clinical manifestations and infection outcomes., (© 2023. The Author(s).)

Background: The purpose of this study was to investigate the typing of adenovirus (AdV) infection in children hospitalized with acute respiratory tract infection (ARTI) and its clinical characteristics., Methods: Samples from 7832 hospitalized children with ARTIs from January 2021 to June 2022 were tested by multiplex PCR for AdV. AdV hex neighborhood genes were amplified and sequenced for typing by nested PCR., Results: Three hundred twenty-eight cases were positive for AdV with rate of 4.48% (328/7832). No statistical difference in the rate of AdV detection was observed in different ages (P > 0.05). Among the 328 cases, 305 cases underwent amplification and sequence determination of AdV five-neighborhood, six-neighborhood and fibronectin genes. Only 237 cases were sequenced successfully for all 3 genetic fragments. The typing results of 231 cases with 3 genes were consistent, with 49.78% (115/231) of type 3, 41.56% (96/231) of type 7 and 8.66% (20/231) of other types identified. The main clinical symptoms in 231 children hospitalized with ARTI who were AdV positive were cough, sputum not easily coughable, Wheezing or shortness of breath and fever. Clinical diagnoses of 231 cases included: acute bronchitis 3.03% (7/231), capillary bronchitis 16.45% (38/231), pneumonia (mild/severe) 76.62% (177/231) (68.40% (158/231) in mild and 8.23% (19/231) in severe cases), bronchial asthma combined with pulmonary infection 3.46% (8/231). Higher percentage of shortness of breath, multilobar infiltration, and pleural effusion were found in type 7. Calcitoninogen in type 7 were significantly higher than those of type 3 and other types, and the white blood cell count was lower than those of type 3 and other types, and the difference was statistically significant (P < 0.05)., Conclusion: AdV type 3 and 7 were frequently found in hospitalized children with acute lower respiratory tract involvement. AdV type 7 seems to be associated with more severe outcome., (© 2023. The Author(s).)

Background: X-linked hyper-immunoglobulin M (XHIGM), a primary immunodeficiency syndrome caused by mutations in the CD40 ligand gene(CD40LG), presents with recurrent respiratory infections in pediatric patients. We aimed to evaluate the spectrum of clinical features and respiratory pathogens in pediatric patients with XHIGM in China., Methods: We retrospectively reviewed seven pediatric patients who were diagnosed with XHIGM and received follow-up treatment at the Guangzhou Women and Children's Medical Center between January 2010 and January 2021. We determined their clinical characteristics, causative pathogens, and prognosis by performing peripheral immunological and genetic tests., Results: There were seven boys with age ranging from 4-20 months (median age, 13 months). Four of the seven respiratory infections were caused by Talaromyces marneffei(T. marneffei). Two patients had viral infections caused by cytomegalovirus (CMV) and human adenovirus respectively. One patient had a mixed infection caused by Pneumocystis carinii and CMV. Except for one child who died of respiratory failure, one patient received hematopoietic stem cell transplantation (HSCT) and recovered well, the other five patients survived with regular infusions of intravenous immunoglobulin (IVIg) during the follow-up period. Six patients had reduced antibody levels, especially IgG, IgA, and IgE levels. Increased serum IgM levels were detected in four cases, and three cases presented normal IgM levels at onset. All children were diagnosed with XHIGM with CD40LG variation. Three novel mutations were identified in the present study., Conclusions: Our study suggests that respiratory infections usually begin within 2 years old, fungi and viruses are important pathogens causing respiratory infections in children with XHIGM. In endemic areas, T. marneffei is the common pathogen of respiratory tract infection in children with the disease., (© 2022. The Author(s).)

Background: Rapid/point-of-care respiratory virus nucleic acid tests (NAT) may improve oseltamivir, antibiotic, diagnostic test, and hospital bed utilization. Previous randomized controlled trials (RCT) on this topic have not used standard procedures of an accredited healthcare and laboratory system., Methods: We conducted a parallel RCT at two hospitals [paediatric = Alberta Children's Hospital (ACH); primarily adult = Peter Lougheed Centre (PLC)]. Patients with a respiratory viral testing order were randomized to testing at either a central accredited laboratory (standard arm) or with a rapid polymerase chain reaction test at an on-site accredited laboratory followed by standard testing [rapid on-site test (ROST) arm] based on day of specimen receipt at the laboratory. Patients and clinicians were blinded to assignment. The primary outcome for ACH was inpatient length of stay (LOS) and for PLC was the proportion of inpatients prescribed oseltamivir., Results: 706 patient encounters were included at ACH; 322 assigned to ROST (181 inpatients) and 384 to the standard arm (194 inpatients). 422 patient encounters were included at PLC; 200 assigned to ROST (157 inpatients) and 222 to the standard arm (175 inpatients). The rate of oseltamivir prescription and number of doses given was reduced in PLC inpatients negative for influenza in the ROST arm compared to standard arm [mean 14.9% (95% CI 9.87-21.9) vs. 27.5% (21.0-35.2), p = 0.0135; mean 2.85 doses (SEM 2.39-3.32) vs. 4.17 doses (3.85-4.49) p = 0.022, respectively]. ROST also significantly reduced oseltamivir use at ACH, reduced chest radiographs (ACH), and laboratory test ordering (PLC), but not antibiotic prescriptions. ROST also reduced the median turnaround time by > 24 h (ACH and PLC). The LOS at ACH was not significantly different between the ROST and standard arms [median 4.05 days (SEM 1.79-18.2) vs 4.89 days (2.07-22.9), p = 0.062, respectively]. No adverse events were reported., Conclusions: In a RCT representing implementation of ROST in an accredited laboratory system, we found that a ROST improved oseltamivir utilization and is the first RCT to show reduced ancillary testing in both paediatric and adult populations. A larger study is required to assess reduction in paediatric LOS as ACH was underpowered. These findings help justify the implementation of rapid on-site respiratory virus testing for inpatients. Trial registration ISRCTN, number 10110119, Retrospectively Registered, 01/12/2021., (© 2022. The Author(s).)

Background: Antimicrobial resistance (AMR) is rising at an alarming rate and complicating the management of infectious diseases including lower respiratory tract infections (LRTI). Metagenomic next-generation sequencing (mNGS) is a recently established method for culture-independent LRTI diagnosis, but its utility for predicting AMR has remained unclear. We aimed to assess the performance of mNGS for AMR prediction in bacterial LRTI and demonstrate proof of concept for epidemiological AMR surveillance and rapid AMR gene detection using Cas9 enrichment and nanopore sequencing., Methods: We studied 88 patients with acute respiratory failure between 07/2013 and 9/2018, enrolled through a previous observational study of LRTI. Inclusion criteria were age ≥ 18, need for mechanical ventilation, and respiratory specimen collection within 72 h of intubation. Exclusion criteria were decline of study participation, unclear LRTI status, or no matched RNA and DNA mNGS data from a respiratory specimen. Patients with LRTI were identified by clinical adjudication. mNGS was performed on lower respiratory tract specimens. The primary outcome was mNGS performance for predicting phenotypic antimicrobial susceptibility and was assessed in patients with LRTI from culture-confirmed bacterial pathogens with clinical antimicrobial susceptibility testing (n = 27 patients, n = 32 pathogens). Secondary outcomes included the association between hospital exposure and AMR gene burden in the respiratory microbiome (n = 88 patients), and AMR gene detection using Cas9 targeted enrichment and nanopore sequencing (n = 10 patients)., Results: Compared to clinical antimicrobial susceptibility testing, the performance of respiratory mNGS for predicting AMR varied by pathogen, antimicrobial, and nucleic acid type sequenced. For gram-positive bacteria, a combination of RNA + DNA mNGS achieved a sensitivity of 70% (95% confidence interval (CI) 47-87%) and specificity of 95% (CI 85-99%). For gram-negative bacteria, sensitivity was 100% (CI 87-100%) and specificity 64% (CI 48-78%). Patients with hospital-onset LRTI had a greater AMR gene burden in their respiratory microbiome versus those with community-onset LRTI (p = 0.00030), or those without LRTI (p = 0.0024). We found that Cas9 targeted sequencing could enrich for low abundance AMR genes by > 2500-fold and enabled their rapid detection using a nanopore platform., Conclusions: mNGS has utility for the detection and surveillance of resistant bacterial LRTI pathogens., (© 2022. The Author(s).)

Background: The associations between viral etiology of acute respiratory infections (ARI) with meteorological factors and air pollutants among children is not fully understood. This study aimed to explore the viral etiology among children hospitalized for ARI and the association of meteorological factors and air pollutants with children hospitalization due to viral ARI., Methods: Electronic health record data about children (aged between 1 month and 14 years) admitted for ARI at Kiang Wu Hospital in Macao between 2014 and 2017 was analyzed retrospectively. xMAP multiplex assays were used to detect viruses in the nasopharyngeal swab and distributed-lag nonlinear model (DLNM) was used to evaluate associations., Results: Among the 4880 cases of children hospitalization due to ARI, 3767 (77.2%) were tested positive for at least one virus and 676 (18%) exhibited multiple infections. Enterovirus (EV)/rhinovirus (HRV), adenovirus (ADV), respiratory syncytial virus (RSV) and influenza virus (IFV) were the most common viral pathogens associated with ARI and human bocavirus (hBOV) exhibited the highest multiple infection rates. Meteorological factors and air pollutants (PM 10 , PM 2.5 and NO 2 ) were associated with the risk of viral ARI hospitalization. The relative risk of viral infection increased with daily mean temperature but plateaued when temperature exceeded 23 °C, and increased when the relative humidity was < 70% and peaked at 50%. The effect of solar radiation was insignificant. Air pollutants (including PM 10 , PM 2.5, NO 2 and O 3 ) showed strong and immediate effect on the incidence of viral infection., Conclusions: The effects of mean temperature, relative humidity and air pollutants should be taken into account when considering management of ARI among children., (© 2022. The Author(s).)

Background: Acute lower respiratory tract infection (ALRTI) in children under 5 years is known to be predominantly caused by respiratory syncytial virus (RSV). In recent times, however, human metapneumovirus (HMPV) has also been implicated. This study sought to investigate and genotype respiratory syncytial virus and human metapneumovirus in children presenting with ALRTIs infection at the Princess Marie Louis Children's Hospital in Accra, Ghana., Methods: Children below 5 years who were clinically diagnosed of ALRTI and on admission at the study site were recruited between September 2015 and November 2016 for this study. Demographic data information was obtained by means of a standardized questionnaire; and relevant clinical information was obtained from medical records. Nasopharyngeal swabs were collected from 176 children recruited for the study. Ribonucleic acid was extracted from swabs and cDNA syntheses were performed by RT-PCR. RSV-positive amplicons were sequenced and analyzed for genotype assignment., Results: RSV and HMPV prevalence among the sampled subjects were 11.4 and 1.7% respectively. Of the RSV positives, 8/20 (40%) were RSV-A and 12/20 (60%) were RSV-B. The highest prevalence was observed in children less than 12 months old. Phylogenetic analysis of the second hypervariable region of the RSV G-gene revealed that all RSV group A viruses belonged to the "novel" ON1 genotype containing the 72-nucleotide duplication; and RSV group B viruses belong to the BA IX genotype., Conclusion: RSV is frequently detected in children aged under 5 years admitted with ALRTI in Ghana. Continued surveillance of viral aetiological agents is warranted to elucidate the prevalence and transmission patterns of viral pathogens that cause respiratory tract infections among children. This will help inform appropriate intervention approaches., (© 2022. The Author(s).)

Background: This study investigated the diagnostic utility of the BioFire FilmArray Pneumonia Panel (PN panel), an automated and multiplexed nucleic acid detection system that rapidly detects 26 pathogens (18 bacteria and eight viruses) and seven antimicrobial resistance markers in a single assay., Methods: We analyzed the targets in lower respiratory tract specimens using the PN panel and compared the detection results with those of bacterial culture methods and antimicrobial susceptibility testing., Results: Of the 57 samples analyzed, the PN panel detected 97 targets (84 bacteria, four viruses, and nine antimicrobial resistance markers). Detection of bacteria and antimicrobial resistance was three times greater than that of the bacterial culture (25 bacteria and two resistant isolates) against the targets available in the panel. The overall positive and negative percent agreements between the PN panel and culture methods for bacterial detection were 100.0% and 92.9%, respectively. Multiple pathogens were detected by the PN panel in 24 samples (42.1%), ranging from two pathogens in 11 samples (19.3%) to six pathogens in one sample (1.8%). The PN panel semiquantitatively detected higher copies (≥ 10 6  copies/mL) of bacterial targets if the bacteria were positive by the culture method. In contrast, the semiquantitative values obtained by the panel varied (10 4 to 10 7  ≤ copies/mL) among bacteria that were negative by the culture method., Conclusions: The PN panel enhanced the detection of pathogens and antimicrobial resistance markers in lower respiratory tract specimens., (© 2022. The Author(s).)

Background: The study describes the application of the multiplex high-resolution melting curve (MHRM) assay for the simultaneous detection of five common bacterial pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii and Escherichia coli) directly from bronchoalveolar lavage samples., Results: Our MHRM assay successfully identified all five respiratory pathogens in less than 5 h, with five separate melting curves with specific melt peak temperatures (Tm). The different Tm were characterized by peaks of 78.1 ± 0.4 °C for S. aureus, 83.3 ± 0.1 °C for A. baumannii, 86.7 ± 0.2 °C for E. coli, 90.5 ± 0.1 °C for K. pneumoniae, 94.5 ± 0.2 °C for P. aeruginosa. The overall sensitivity and specificity of MHRM were 100% and 88.8-100%, respectively., Conclusions: Our MHRM assay offers a simple and fast alternative to culture approach for simultaneous detection of five major bacterial lower respiratory tract infection pathogens. Utilization of this assay can help clinicians initiate prompt and appropriate antimicrobial treatment, towards reducing the morbidity and mortality of severe respiratory infections., (© 2022. The Author(s).)

Background: The prevalence of virus positivity in the upper respiratory tract of asymptomatic community-dwelling older people remains elusive. Our objective was to investigate the prevalence of respiratory virus PCR positivity in asymptomatic community-dwelling older people using saliva samples and nasopharyngeal and oropharyngeal swabs., Methods: We analyzed 504 community-dwelling adults aged ≥ 65 years who were ambulatory and enrolled in a cross-sectional study conducted from February to December 2018 in Nagasaki city, Japan. Fourteen respiratory viruses were identified in saliva, nasopharyngeal and oropharyngeal samples using multiplex PCR assays., Results: The prevalences of PCR positivity for rhinovirus, influenza A, enterovirus and any respiratory virus were 12.9% (95% CI: 10.1-16.1%), 7.1% (95% CI: 5.1-9.8%), 6.9% (95% CI: 4.9-9.5%) and 25.2% (95% CI: 21.5-29.2%), respectively. Rhinovirus was detected in 21.5% of subjects, influenza A in 38.9% of subjects, enterovirus in 51.4% of subjects and any virus in 32.3% of subjects using only saliva sampling., Conclusions: The prevalences of several respiratory viruses were higher than the percentages reported previously in pharyngeal samples from younger adults. Saliva sampling is a potentially useful method for respiratory virus detection in asymptomatic populations., (© 2022. The Author(s).)

Background: Acute respiratory infections (ARI) are the leading cause of morbidity and mortality in children below 5 years of age., Methods: This multisite prospective observational study was carried out in the Pediatrics' out-patient departments of 5 medical colleges across India with an objective to assess the feasibility of establishing Acute Respiratory Infection Treatment Unit (ATU) in urban medical college hospitals. ATU (staffed with a nurse and a medical officer) was established in the out-patient areas at study sites. Children, aged 2-59 months, with cough and/ breathing difficulty for < 14 days were screened by study nurse in the ATU for pneumonia, severe pneumonia or no pneumonia. Diagnosis was verified by study doctor. Children were managed as per the World Health Organization (WHO) guidelines. The key outcomes were successful establishment of ATUs, antibiotic usage, treatment outcomes., Results: ATUs were successfully established at the 5 study sites. Of 18,159 under-five children screened, 7026 (39%) children were assessed to have ARI. Using the WHO criteria, 938 were diagnosed as pneumonia (13.4%) and of these, 347 (36.9%) had severe pneumonia. Ambulatory home-based management was done in 6341 (90%) children with ARI; of these, 16 (0.25%) required admission because of non-response or deterioration on follow-up. Case-fatality rate in severe pneumonia was 2%. Nearly 12% of children with 'no pneumonia' received antibiotics., Conclusions: Setting up of ATUs dedicated to management of ARI in children was feasible in urban medical colleges. The observed case fatality, and rate of unnecessary use of antibiotics were lower than that reported in literature., (© 2022. The Author(s).)

Background: Acute lower respiratory infection (ALRI) remains the leading cause of death in children worldwide, and viruses have been the major cause of ALRI. In Myanmar, ALRI is associated with high morbidity and mortality in children, and detailed information on ALRI is currently lacking., Methods: This prospective study investigated the viral aetiologies, clinical manifestations, and outcomes of ALRI in hospitalised children aged 1 month to 12 years at the Yankin Children Hospital, Yangon, Myanmar from May 2017 to April 2019. The sample size was set to 300 patients for each year. Two nasopharyngeal swabs were obtained for the patients with suspected viral ALRI; one for rapid tests for influenza and respiratory syncytial virus (RSV), and the other for real-time PCR for the 16 ALRI-causing viruses. Pneumococcal colonization rates were also investigated using real-time PCR. Clinical information was extracted from the medical records, and enrolled patients were categorised by age and severity for comparison., Results: Among the 5463 patients admitted with a diagnosis of ALRI, 570 (10.4%) were enrolled in this study. The median age of the patients was 8 months (interquartile range, 4-15 months). The most common symptoms were cough (93%) and difficulty in breathing (73%), while the most common signs of ALRI were tachypnoea (78%) and chest indrawing (67%). A total of 16 viruses were detected in 502 of 570 patients' samples (88%), with RSV B (36%) and rhinovirus (28%) being the most commonly detected. Multiple viruses were detected in 221 of 570 samples (37%) collected from 570 patients. Severe ALRI was diagnosed in 107 of 570 patients (19%), and RSV B and human rhinovirus were commonly detected. The mortality rate was 5%; influenza virus A (29%) and RSV B (21%) were commonly detected, and stunting and lack of immunization were frequently observed in such cases. Additionally, 45% (259/570) of the patients had pneumococcal colonization., Conclusions: Viral ALRI in hospitalised children with a median of 8 months has significant morbidity and mortality rates in Myanmar. RSV and rhinovirus were the most commonly detected from nasopharyngeal swabs, while influenza virus and RSV were the most frequently associated with fatal cases., (© 2022. The Author(s).)

Background: Respiratory virus infection is common in early childhood, and children may be symptomatic or symptom-free. Little is known regarding the association between symptomatic/asymptomatic infection and particular clinical factors such as breastfeeding as well as the consequences of such infection., Method: We followed an unselected cohort of term neonates to two years of age (220 infants at recruitment, 159 who remained in the study to 24 months), taking oral swabs at birth and oropharyngeal swabs at intervals subsequently (at 1.5, 6, 9, 12, 18 and 24 months and in a subset at 3 and 4.5 months) while recording extensive metadata including the presence of respiratory symptoms and breastfeeding status. After 2 years medical notes from the general practitioner were inspected to ascertain whether doctor-diagnosed wheeze had occurred by this timepoint. Multiplex PCR was used to detect a range of respiratory viruses: influenza (A&B), parainfluenza (1-4), bocavirus, human metapneumovirus, rhinovirus, coronavirus (OC43, 229E, NL63, HKU1), adenovirus, respiratory syncytial virus (RSV), and polyomavirus (KI, WU). Logistic regression and generalised estimating equations were used to identify associations between clinical factors and virus detection., Results: Overall respiratory viral incidence increased with age. Rhinovirus was the virus most frequently detected. The detection of a respiratory virus was positively associated with respiratory symptoms, male sex, season, childcare and living with another child. We did not observe breastfeeding (whether assessed as the number of completed months of breastfeeding or current feed status) to be associated with the detection of a respiratory virus. There was no association between early viral infection and doctor-diagnosed wheeze by age 2 years., Conclusion: Asymptomatic and symptomatic viral infection is common in the first 2 years of life with rhinovirus infection being the most common. Whilst there was no association between early respiratory viral infection and doctor-diagnosed wheeze, we have not ruled out an association of early viral infections with later asthma, and long-term follow-up of the cohort continues., (© 2022. The Author(s).)

Background: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory tract infection in infants. Globally, RSV is responsible for approximately 3.2 million hospital admissions and about 60,000 in-hospital deaths per year., Methods: Infection with RespIratory Syncytial Virus (IRIS) is an observational, multi-centre study enrolling infants with severe RSV infection and healthy controls. Inclusion criteria are age between 0 and 36 months and hospitalisation due to RSV infection at three German sites. Exclusion criteria are premature birth, congenital or acquired bronchopulmonary or cardiac diseases, and immunodeficiency. Healthy control probands are enrolled via recruitment of patients undergoing routine surgical procedures. Blood and respiratory specimens are collected upon admission, and RSV and other pathogens are analysed by multiplex polymerase chain reaction. Different biomaterials, including plasma, nasal lining fluid, blood cells, DNA, and RNA specimens, are sampled in a dedicated biobank. Detailed information on demographic characteristics and medical history is recorded, and comprehensive clinical data, including vital signs, medication, and interventions., Discussion: The IRIS study aims to discover host and viral factors controlling RSV disease courses in infants. The approach including multi-omics characterisation in clinically well-characterized children with RSV bronchiolitis seeks to improve our understanding of the immune response against this virus. It may disclose novel diagnostic and treatment approaches for respiratory infections in infants., Trial Registration: ClinicalTrials.gov, NCT04925310. Registered 01 October 2021-Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT04925310?cond=NCT04925310&draw=2&rank=1., (© 2022. The Author(s).)

Background: Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) infection can lead to a broad spectrum of lung diseases, including infectious diseases and tumors. Recently, with the wide application of bronchoscopes and cytopathology of bronchoalveolar lavage fluid (BALF), the diagnostic efficiency of lung diseases has improved. The present study focuses on analyzing the cytopathologic characteristics of BALF in the diagnosis of HIV/AIDS-related lung disease and comparing the lung disease spectrum between HIV and HIV-uninfected patients., Methods: BALF specimens were collected from 2211 patients. Using ThinPrep liquid-based technology, the cytologic smears were prepared by staining with Hematoxylin and Eosin (HE), Gomori's methenamine silver (GMS), and Periodic Acid Schiff (PAS), acid-fast and immunocytochemical (ICC) staining. Real-time PCR was used to detect cytomegalovirus (CMV) and Mycobacterium tuberculosis (M. tuberculosis) in the remaining BALF. PCR-reverse dot hybridization was used for mycobacterial species identification., Results: From the 2211 BALF specimens, 1768 (79.96%) were specimens from HIV-infected patients, and 443 (20.04%) were speciments from HIV-uninfected patients. The HIV-infected patients with a median age of 38.5 ± 11.3 years were markedly younger than the HIV-uninfected patients (52.9 ± 14.9 years) (p < 0.01). We found that 1635 (92.5%) HIV-infected patients were males, showing a prominently higher proportion than those without HIV infection (71.1%) (p < 0.01). Meanwhile, 1045 specific lesions were found in 1768 HIV-infected patients (59.1%), including 1034 cases of infectious diseases and 11 neoplastic lesions, also exhibiting a distinctly higher proportion compared to the HIV-uninfected patients (12.2%) (p < 0.001). For the HIV-infected group, a distinctly higher proportion of single infection lesions (724/1768, 41%) was noted than the HIV-uninfected group (14/443, 3.2%) (p < 0.001). Among single infection lesions, the most common was Cytomegalovirus(CMV) infection (20.9%) for the HIV-infected group, followed by Pneumocystis jiroveci(PJ) (13.0%), Fungal (3.5%), and Mycobacterial infections (3.4%), of which M. tuberculosis infection accounted for 3.1%. Double infections (300/1768, 17.0%) and Triple infections (10/1768, 0.6%) were found only among the patients with HIV. The malignancies among HIV-infected patients included adenocarcinomas (0.22%), small cell carcinomas (0.2%), squamous cell carcinomas (0.1%), and diffuse large B-cell lymphoma (0.1%). HIV-infected patients exhibited a significantly lower incidence of neoplastic lesions (0.6% vs. 9.0%) than the HIV-uninfected patients (p < 0.001)., Conclusions: There was a significant difference in the spectrum of lung diseases between HIV-infected and non-infected patients diagnosed by BALF cytopathology., (© 2022. The Author(s).)

Introduction: The incidence of acute respiratory tract infections (ARTIs) in children is difficult to estimate because they are typically treated in outpatient settings and the majority of epidemiological data originate from hospital settings and refer to the most severe illnesses. Therefore, the incidence of ARTIs in a real-world setting remains largely unexplored. Therefore, this study aims to estimate the incidence of ARTIs, upper respiratory tract infections (URTIs), and lower respiratory tract infections (LRTIs) in children aged 0-5 years in an outpatient setting., Methods: This prospective cohort study was conducted in Lombardy, Italy, from October 1st, 2019, to March 31st, 2021, before and during the COVID-19 pandemic that began in March 2020. Caucasian healthy children aged 0-5 years were recruited from 69 Family Pediatricians (FP) and followed-up in an outpatient setting. Data were collected whenever a child was referred to FP and ARTI was diagnosed (Covid-19 related ARTI were excluded). The primary outcome was an estimate of the incidence of ARTIs. The incidence of ARTIs in different age groups and the effect of the COVID-19 pandemic on the incidence of ARTIs were secondary outcomes., Results: We enrolled 484 children, 249 male (51.8%), mean age of 2.39 ± 1.68 years. The mean estimated incidence of ARTIs was 12.1/100 children × 30 days (95% CIs: 9.5-12.9), with the highest value observed in infants aged 1-12 months (24.9/100 children × 30 days; 95% CIs: 17.6-28.9). The mean estimated incidence of URTIs was higher than that of LRTIs (8.3 - CIs: 7.6-8.9 vs 3.8/100 children × 30 days - CIs: 6.4-4.3, respectively). The comparison of ARTIs, which occurred in the pre-pandemic winter, to those measured during the COVID-19 pandemic, revealed an impressive 82.1% drop in the incidence rate (CIs: 77.8-85.7)., Conclusions: This study showed that infants aged 1-12 months are more likely to develop ARTIs than older children and that COVID-19 pandemic has dramatically altered the epidemiology of ARTIs in children aged 0-5 years., (© 2022. The Author(s).)

Objective: To evaluate the role and the advantages of nasopharyngeal swabs in the detection of Influenza A and B viruses and Respiratory syncytial virus through a rapid test based upon a nucleic acid amplification reaction in order to avoid improper antibiotics use., Design: Case-control retrospective study., Setting: Emergency Room of "Sandro Pertini" General Hospital, Rome, Italy., Participants: Children (< 14 years old) who consecutively arrived in the Emergency Department (ED) for respiratory tract infections, without obvious signs of bacterial respiratory tract infections and other comorbidities, in the maximal seasonal incidence period of November-to-March of every year between 2016 and 2020., Methods: Medical records of children included in the study were retrospectively examined. Children were subdivided according to the following intervals: 2016-2017 and 2017-2018 (Group 1), 2018-2019 and 2019-2020 (Group 2). Children in Group 2 undertook a nasopharyngeal swab, while those in Group 1 did not undergo any specific diagnostic test., Primary Outcome: Avoidance of improper antibiotics administration., Results: A total of 386 children were included in the study: 174 in Group 1, 212 in Group 2. The Odd Ratio (OR) of prescribing an antibiotic in the groups of children not being swabbed compared to those of children undertaking a swab was 9.21 (CI95% 5.6-15.2, p < 0.001). The overall percentage of hospitalizations, both in the short observation unit or in the pediatric unit, did not differ between the two groups., Conclusions: Nasopharyngeal swabs for the detection of Influenza A and B viruses and Respiratory syncytial virus proved to be a useful means to a correct and timely diagnosis and allowed for a significant reduction in the prescription of antibiotic therapy., Trial Registration: Retrospectively registered., (© 2022. The Author(s).)