Respiratory infections

[The impact of maternal smoking during pregnancy on respiratory disease in children]

Among the causes of abnormal fetal lung development, active and environmental maternal smoking represents a major potential target in preventive medicine. Prevalence of smoking among women, particularly during pregnancy, varies across the different regions of the world. We reviewed the literature on the repercussions of maternal smoking on the lungs of the fetus and the neonate. One of the main consequences is prematurity, leading to pulmonary bronchodysplasia followed by respiratory infections, which particularly affect young children. In the medium- and long-term, smoking in utero leads to asthma and allergies, and is suspected to be associated with impaired respiratory function in children and teenagers. We also report on the potential effects of e-cigarettes, which represent an emerging threat to children's respiratory health.

Key performance evaluation of commercialized multiplex rRT-PCR kits for respiratory viruses: implications for application and optimization

Respiratory tract infections (RTIs) caused by viruses are prevalent and significant conditions in clinical settings. Accurate and effective detection is of paramount importance in the diagnosis, treatment, and prevention of viral RTIs. With technological advancements, multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been developed and extensively adopted for the diagnosis of viral RTIs. Given the potential challenges in the detection performance of multiplex assays, this study evaluated the analytical sensitivity and competitive interference of the six most commonly used multiplex rRT-PCR kits for detection of respiratory viruses in China. The results revealed that the limits of detection were variable across the viruses and kits. Most of the evaluated multiplex kits demonstrated comparable or enhanced analytical sensitivity compared with singleplex kits for clinically significant viruses, including human adenovirus (HAdV)-3, HAdV-7, Omicron BA.5, H1N1pdm09, H3N2, B/Victoria, respiratory syncytial virus subtype A, and respiratory syncytial virus subtype B, whereas multiplex kits showed relatively less analytical sensitivity for human rhinovirus-B72, human metapneumovirus-A2, parainfluenza virus (PIV)-1, and PIV-3. In addition, most multiplex kits successfully identified co-infections when one analyte was present at a low concentration and another analyte was present at a high concentration.

IMPORTANCE

The complexity and severity of viral respiratory tract infections (RTIs) emphasize the pivotal role of precise diagnosis for viral RTIs in guiding effective public health responses and ensuring appropriate medical interventions, given the substantial population at risk. This study highlights the necessity and importance of evaluating the analytical validity of multiplex real-time reverse transcription polymerase chain reaction assays, offering valuable insights into their optimization and application.

Epidemiological characteristics and meteorological factors of acute respiratory infections (ARIs) in hospitalized children in eastern Guangdong, China

Acute respiratory infections (ARIs) are the most common issue in pediatric clinical practice. They pose a significant public threat, with high morbidity and mortality rates worldwide. Aiming at understanding the epidemiological characteristics of respiratory pathogens and their risk factors among children in eastern Guangdong, China. Samples obtained from 15,993 children hospitalized with ARIs in eastern Guangdong Province were tested for 14 pathogens via multiplex polymerase chain reaction (PCR) from May 2019 to July 2023. The number of hospitalizations for ARIs was correlated with pathogens, age, meteorological parameters, and the pandemic of COVID-19. The data were analyzed by different statistical methods. Among all the samples, the positive rate with ARIs accounted for 68.94% (11,026/15,993) in hospitalized patients. Cytomegalovirus (CMV) (24.49%), Streptococcus pneumoniae (SP) (20.54%), and Respiratory Syncytial Virus (RSV) (14.16%) were the top three pathogens with the greatest infection rates. Among hospitalized patients, there were more single infections in pediatric patients (40.91%, P < 0.001). Compared with bacterial infection and mixed infection, the detection rate of virus infection was higher in pediatric (36.04%, P < 0.001). Age-related increases in Mycoplasma pneumoniae (MP) infection (r = 0.729, P < 0.001) and decreases in RSV infection were observed (r = 0.88, P < 0.001). The virus infection peaked at six months, and the bacterial infection and mixed infection peaked at 1-3 years. Viral pathogens are on the rise in the post-pandemic era. The prevalence of SP infection was more influenced by the Air Quality Index (AQI), RSV infections were more clearly influenced by temperature, and Influenza A virus (IAV) infections were more strongly correlated with both the AQI and relative humidity (P < 0.001). This study highlights the need of keeping an eye on monitoring meteorological factors in assessing hospitalizations for pediatric ARIs in eastern Guangdong, China, especially RSV- and SP-associated hospitalizations.

Portable and simultaneous detection of four respiratory pathogens through a microfluidic LAMP and real-time fluorescence assay

Respiratory pathogen infections are seasonally prevalent and are likely to cause co-infections or serial infections during peak periods of infection. Since they often cause similar symptoms, simultaneous and on-site detection of respiratory pathogens is essential for accurate diagnosis and efficient treatment of these infectious diseases. However, molecular diagnostic techniques for multiple pathogens in this field are lacking. Herein, we developed a microfluidic LAMP and real-time fluorescence assay for rapid detection of multiple respiratory pathogens using a ten-channel microfluidic chip with pathogen primers pre-embedded in the chip reaction well. The microfluidic chip provided a closed reaction environment, effectively preventing aerosol contamination and improving the accuracy of the detection results. Its corresponding detection instrument could automatically collect and display the fluorescence curve in real time, which was more conducive to the interpretation of results. The results showed that the developed method could specifically recognize the nucleic acid of influenza A(H1N1), Mycoplasma pneumoniae, respiratory syncytial virus type A, and SARS-CoV-2 with low detection limits of 104 copies per mL or 103 copies per mL. The test results on clinical samples demonstrated that the developed method has high sensitivity (92.00%) and high specificity (100.00%) and even has the capability to differentiate mixed-infection samples. With simple operation and high detection efficiency, the present portable and simultaneous detection assay could significantly improve the efficiency of on-site detection of respiratory infectious diseases and promote the accurate treatment, efficient prevention and control of the diseases.

Establishment of a Raman nanosphere based immunochromatographic system for the combined detection of influenza A and B viruses' antigens on a single T-line

A simple and rapid system based on Raman nanosphere (R-Sphere) immunochromatography was developed in this study for the simultaneous detection of Influenza A, B virus antigens on a single test line (T-line). Two types of R-Sphere with different characteristic Raman spectrum were used as the signal source, which were labeled with monoclonal antibodies against FluA, FluB (tracer antibodies), respectively. A mixture of antibodies containing anti-FluA monoclonal antibody and anti-FluB monoclonal antibody (capture antibody) was sprayed on a single T-line and goat anti-chicken IgY antibody was coated as a C-line, and the antigen solution with known concentration was detected by the strip of lateral flow immunochromatography based on surface-enhanced Raman spectroscopy (SERS). The T-line was scanned with a Raman spectrometer and SERS signals were collected. Simultaneous specific recognition and detection of FluA and FluB were achieved on a single T-line by analyzing the SERS signals. The findings indicated that the test system could identify FluA and FluB in a qualitative manner in just 15 minutes, with a minimum detection threshold of 0.25 ng ml-1, excellent consistency, and specificity. There was no interference with the other four respiratory pathogens, and it exhibited 8 times greater sensitivity compared to the colloidal gold test strip method. The assay system is rapid, sensitive, and does not require repetitive sample pretreatment steps and two viruses can be detected simultaneously on a single T-line by titrating one sample, which improves detection efficiency, and provide a reference for developing multiplexed detection techniques for other respiratory viruses.

Anti-Inflammatory, Antibacterial, Anti-Biofilm, and Anti-Quorum Sensing Activities of the Diterpenes Isolated from Clinopodium bolivianum

This study reports for the first time the isolation of four diterpenoid compounds: 15-Hydroxy-12-oxo-abietic acid (1), 12α-hydroxyabietic acid (2), (-)-Jolkinolide E (3), and 15-Hydroxydehydroabietic acid (4) from Clinopodium bolivianum (C. bolivianum). The findings demonstrate that both the dichloromethane/methanol (DCMECB) extract of C. bolivianum and the isolated compounds exhibit significant anti-inflammatory (inhibition of NF-κB activation), antibacterial (primarily against Gram-positive bacteria), and anti-biofilm (primarily against Gram-negative bacteria) activities. Among the isolated diterpenes, compounds 3 and 4 showed notable anti-inflammatory effects, with IC50 values of 17.98 μM and 23.96 μM for compound 3, and 10.79 μM and 17.37 μM for compound 4, in the HBEC3-KT and MRC-5 cell lines. Regarding their antibacterial activity, compounds 3 and 4 were particularly effective, with MIC values of 0.53-1.09 μM and 2.06-4.06 μM, respectively, against the S. pneumoniae and S. aureus Gram-positive bacteria. Additionally, these compounds demonstrated significant anti-biofilm and anti-quorum sensing activities, especially against Gram-negative bacteria (H. influenzae and L. pneumophila). We also explain how compound 3 (BIC = 1.50-2.07 μM, Anti-QS = 0.31-0.64 μM) interferes with quorum sensing due to its structural homology with AHLs, while compound 4 (BIC = 4.65-7.15 μM, Anti-QS = 1.21-2.39 μM) destabilises bacterial membranes due to the presence and position of its hydroxyl groups. These results support the traditional use of C. bolivianum against respiratory infections caused by both Gram-positive and Gram-negative bacteria. Furthermore, given the increasing antibiotic resistance and biofilm formation by these bacteria, there is a pressing need for the development of new, more active compounds. In this context, compounds 3 and 4 isolated from C. bolivianum offer promising potential for the development of a library of new, more potent, and selective drugs.

Distribution characteristics of human herpes viruses in the lower respiratory tract and their impact on 30-day mortality in community-acquired pneumonia patients

Human herpes viruses (HHVs) are commonly detected in community-acquired pneumonia (CAP) patients, particularly those with complex complications, attracting increased attention from clinical practitioners. However, the significance of detecting HHVs in bronchoalveolar lavage fluid (BALF) with CAP patients is still unclear. This study retrospectively analyzed BALF samples from 64 CAP patients at the Kunming Third People's Hospital between August 2021 and December 2023. Metagenomic next generation sequencing (mNGS) was conducted on BALF samples during CAP onset. Multivariate Cox regression models were used to identify independent risk factors for 30-day all-cause mortality in CAP. HHVs were found in 84.4% of CAP patients, which were the most common pathogens (45.1%), followed by bacteria (30.2%) and fungi (11.5%). Bacterial-viral co-infections were most common, occurring in 39 patients. Notably, there was no significant difference in HHV presence between severe and non-severe CAP patients (EBV: P = 0.431, CMV: P = 0.825), except for HHV-7 (P = 0.025). In addition, there was no significant difference in the 30-day mortality between HHV positive and HHV negative groups (P = 0.470), as well as between the HHV-7 positive and HHV-7 negative groups (P = 0.910). However, neither HHVs nor HHV-7 was independent risk factors for 30-day mortality in CAP patients (HHVs: HR 1.171, P = 0.888; HHV-7: HR 1.947, P = 0.382). In summary, among the prevalent presence of multiple HHVs, EBV and CMV were the most prevalent in CAP patients. Patients with sCAP were more susceptible to HHV-7 than those with non-sCAP. These results provide valuable insights for clinicians in guiding appropriate interventions for CAP treatment.

Aquaporin 1 aggravates lipopolysaccharide-induced macrophage polarization and pyroptosis

Acute respiratory infections (ARIs) are associated with high mortality and morbidity. Acute lung injury (ALI) is caused by the activation of immune cells during ARIs caused by viruses such as SARS-CoV-2. Aquaporin 1 (AQP1) is distributed in a variety of immune cells and is related to the occurrence of ALI, but the mechanism is not clear. A reference map of human single cells was used to identify macrophages in COVID-19 patients at the single-cell level. "FindMarkers" was used to analyze differentially expressed genes (DEGs), and "clusterProfiler" was used to analyze the functions of the DEGs. An M1 macrophage polarization model was established with lipopolysaccharide (LPS) in vitro, and the relationships among AQP1, pyroptosis and M1 polarization were examined by using an AQP1 inhibitor. Transcriptome sequencing and RT-qPCR were used to examine the molecular mechanism by which AQP1 regulates macrophage polarization and pyroptosis. Antigen presentation, M1 polarization, migration and phagocytosis are abnormal in SARS-CoV-2-infected macrophages, which is related to the high expression of AQP1. An M1 polarization model of macrophages was constructed in vitro, and an AQP1 inhibitor was used to examine whether AQP1 could promote M1 polarization and pyroptosis in response to LPS. Transcriptome and cell experiments showed that this effect was related to a decrease in chemokines caused by AQP1 deficiency. AQP1 participates in M1 polarization and pyroptosis in macrophages by increasing the levels of chemokines induced by LPS, which provides new insights for the diagnosis and treatment of ALI.

The diagnostic value of bronchoalveolar lavage fluid metagenomic next-generation sequencing in critically ill patients with respiratory tract infections

Metagenomic next-generation sequencing (mNGS) is an unbiased and rapid method for detecting pathogens. This study enrolled 145 suspected severe pneumonia patients who were admitted to the Affiliated Hospital of Jining Medical University. This study primarily aimed to determine the diagnostic performance of mNGS and conventional microbiological tests (CMTs) using bronchoalveolar lavage fluid samples for detecting pathogens. Our findings indicated that mNGS performed significantly higher sensitivity (97.54% vs 28.68%, P < 0.001), coincidence (90.34% vs 35.17%, P < 0.001), and negative predictive value (80.00% vs 13.21%, P < 0.001) but performed lower specificity than CMTs (52.17% vs 87.5%, P < 0.001). Streptococcus pneumoniae as the most common bacterial pathogen had the largest proportion (22.90%, 30/131) in this study. In addition to bacteria, fungi, and virus, mNGS can detect a variety of atypical pathogens such as Mycobacterium tuberculosis and non-tuberculous. Mixed infections were common in patients with severe pneumonia, and bacterial-fungal-viral-atypical pathogens were the most complicated infection. After adjustments of antibiotics based on mNGS and CMTs, the clinical manifestation improved in 139 (95.86%, 139/145) patients. Our data demonstrated that mNGS had significant advantage in diagnosing respiratory tract infections, especially atypical pathogens and fungal infections. Pathogens were detected timely and comprehensively, contributing to the adjustments of antibiotic treatments timely and accurately, improving patient prognosis and decreasing mortality potentially.IMPORTANCEMetagenomic next-generation sequencing using bronchoalveolar lavage fluid can provide more comprehensive and accurate pathogens for respiratory tract infections, especially when considering the previous usage of empirical antibiotics before admission or complicated clinical presentation. This technology is expected to play an important role in the precise application of antimicrobial drugs in the future.

Evaluation of the FPMC respiratory panel for detection of respiratory tract pathogens in nasopharyngeal swab and sputum specimens

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.

A prospects tool in virus research: Analyzing the applications of organoids in virus studies

Organoids have emerged as a powerful tool for understanding the biology of the respiratory, digestive, nervous as well as urinary system, investigating infections, and developing new therapies. This article reviews recent progress in the development of organoid and advancements in virus research. The potential applications of these models in studying virul infections, pathogenesis, and antiviral drug discovery are discussed.

Managing children with frequent respiratory infections and associated wheezing: a preliminary randomized study with a new multicomponent nasal spray

BACKGROUND

Preschoolers frequently have respiratory infections (RIs), which may cause wheezing in some subjects. Type 2 polarization may favor increased susceptibility to RIs and associated wheezing. Non-pharmacological remedies are garnering increasing interest as possible add-on therapies. The present preliminary study investigated the efficacy and safety of a new multi-component nasal spray in preschoolers with frequent RIs and associated wheezing.

METHODS

Some preschoolers with these characteristics randomly took this product, containing lactoferrin, dipotassium glycyrrhizinate, carboxymethyl-beta-glucan, and vitamins C and D3 (Saflovir), two sprays per nostril twice daily for 3 months. Other children were randomly treated only with standard therapy. Outcomes included the number of RIs and wheezing episodes, use of medications, and severity of clinical manifestations.

RESULTS

Preschoolers treated add-on with this multicomponent product experienced fewer RIs and used fewer beta-2 agonists than untreated children (P = 0.01 and 0.029, respectively).

CONCLUSIONS

This preliminary study demonstrated that a multicomponent product, administered add-on as a nasal spray, could reduce the incidence of RIs and use of symptomatic drugs for relieving wheezing in children.

Developing a model of public health system strengthening during pandemic of new emerging respiratory diseases for Iran: A protocol study

The objective of this article is to propose a protocol for developing a model for strengthening the public health system in Iran. Currently, there is no clearly articulated model for strengthening public health systems during the pandemic of new emerging respiratory diseases in Iran. The protocol described here aims to: (1) identify components for strengthening public health systems, during the pandemic of new emerging respiratory diseases worldwide, (2) identify components for strengthening Iran's public health system, and (3) design a model for strengthening the public health system in Iran during the pandemic of new emerging respiratory diseases. The protocol proposes three phases. In the first phase, a realistic review will be conducted to identify components for strengthening public health systems worldwide based on six building block framework. In the second phase, a qualitative study will be used to identify components for strengthening public health systems in Iran during the pandemic of new emerging respiratory diseases. In the third phase, an initial model will be designed, and the Delphi technique will be used to finalize the model. Due to fragility and the significant strain that public health systems experienced during the pandemic, it is imperative to introduce a model that strengthens public health systems through some initiatives and strategies and explains the mechanisms by which they operate. A realist review and qualitative study will provide the evidence needed to support the effective implementation of public health interventions, taking into consideration the diverse contexts of these interventions in Iran.

Near-Infrared Responsive Ag@Au Nanoplates with Exceptional Stability for Highly Sensitive Colorimetric and Photothermal Dual-Mode Lateral Flow Immunoassay

Lateral flow immunoassay (LFIA) has played a vital role in point-of-care (POC) testing on account of its simplicity, rapidity, and low cost. However, the low sensitivity and difficulty of quantitation limit its further development. Sensitive markers with new detection modes are being developed to dramatically improve LFIA's performance. Herein, a ligand-complex approach was proposed to uniformly coat a thin layer of Au onto Ag triangular nanoplates (Ag TNPs) without etching the Ag cores, which not only retain the unique optical properties from Ag TNPs but also acquire the surface stability and biocompatibility of gold. The localized surface plasmon resonance absorption of these Ag@Au TNPs could be finely adjusted from visible (550 nm) to the second near-infrared region (NIR-II) (1100 nm), and even longer, by simply adjusting the ratio between edge length and thickness. Utilizing the Ag@Au TNPs as new markers for LFIA, a highly sensitive colorimetric and photothermal dual-mode detection of the SARS-CoV-2 nucleocapsid protein was achieved with a very low background. The Ag@Au TNPs showed an exceedingly high photothermal conversion efficiency of 61.4% (ca. 2 times higher than that of Au nanorods), endowing the LFIA method with a low photothermal detection limit (40 pg/mL), which was 25-fold lower than that of the colorimetric results. The generality of the method was further verified by the sensitive and accurate analysis of cardiac troponin I (cTnI). This method is robust, reproducible, and highly specific and has been successfully applied to SARS-COV-2 detection in 35 clinical samples with satisfactory results, demonstrating its potential for POC applications.

In Silico Clinical Trials: Is It Possible?

Modeling and simulation (M&S), including in silico (clinical) trials, helps accelerate drug research and development and reduce costs and have coined the term "model-informed drug development (MIDD)." Data-driven, inferential approaches are now becoming increasingly complemented by emerging complex physiologically and knowledge-based disease (and drug) models, but differ in setup, bottlenecks, data requirements, and applications (also reminiscent of the different scientific communities they arose from). At the same time, and within the MIDD landscape, regulators and drug developers start to embrace in silico trials as a potential tool to refine, reduce, and ultimately replace clinical trials. Effectively, silos between the historically distinct modeling approaches start to break down. Widespread adoption of in silico trials still needs more collaboration between different stakeholders and established precedence use cases in key applications, which is currently impeded by a shattered collection of tools and practices. In order to address these key challenges, efforts to establish best practice workflows need to be undertaken and new collaborative M&S tools devised, and an attempt to provide a coherent set of solutions is provided in this chapter. First, a dedicated workflow for in silico clinical trial (development) life cycle is provided, which takes up general ideas from the systems biology and quantitative systems pharmacology space and which implements specific steps toward regulatory qualification. Then, key characteristics of an in silico trial software platform implementation are given on the example of jinkō.ai (nova's end-to-end in silico clinical trial platform). Considering these enabling scientific and technological advances, future applications of in silico trials to refine, reduce, and replace clinical research are indicated, ranging from synthetic control strategies and digital twins, which overall shows promise to begin a new era of more efficient drug development.

Epidemiological Study of Respiratory Virus Infections among Hospitalized Children Aged 14 Years and Younger during COVID-19 Pandemic in Wuhan, China, 2018-2022

Introduction

The viral etiological characteristics and prevalence of hospitalized children with acute respiratory tract infection were preliminary studied in Wuhan City during the COVID-19 pandemic, to provide a reliable scientific basis for better understanding of the role of various pathogens in cases and for the prevention and clinical treatment of acute respiratory tract infection.

Methods

A total of 69,086 children with acute respiratory infections hospitalized and treated in our department from January 2018 to December 2022 were enrolled as our research subjects. Sociodemographic and clinical data as well as nasopharyngeal samples were collected from patients. Respiratory syncytial virus (RSV), adenovirus (ADV), infuenza virus A (FluA), infuenza virus B (FluB), and parainfluenza virus (PIV) were detected by direct immunofluorescence (DFA) to understand and analyze the epidemic characteristics of respiratory pathogens in children during the COVID-19 pandemic.

Results

The total detection rate of respiratory pathogens was 24.52% of the 69,086 hospitalized children. The frequency of respiratory viruses in those ADV, RSV, FluA, FluB, and PIV was 14.67%, 46.40%, 7.76%, 5.23%, and 25.95%. There were significant differences between the various pathogens (P < 0.001). There were the fewest pathogen-positive patients and positive detection rate in 2020 during the COVID-19 pandemic. There were significant differences in the pathogen detection rate among different years (P < 0.001). In addition, the results showed that the total detection rate of respiratory virus tested in different age groups was significantly different (P < 0.001). The positive detection rate was highest in the 1-3-year-old age group, which is prone to acute respiratory infections. We also found that different pathogens showed obvious seasonal fluctuation and epidemic. RSV reached its peak in winter. ADV is mainly prevalent in spring and summer. FluA has a high detection rate in winter. Winter and spring are the peak seasons for FluB infection, whereas PIV is detected in all seasons, with a higher incidence rate in the spring and summer.

Conclusion

The epidemiological distribution of pathogens of acute respiratory tract infection in hospitalized children in Wuhan from 2018 to 2022 varies with gender, age, and season. Nonpharmaceutical interventions (NPIs) were implemented as control measures worldwide and reduced the transmission of respiratory pathogens. NPIs are likely to be the primary driver of the dramatic reduction in respiratory virus infection activity in the early stages of the COVID-19 pandemic, to dissolving NPIs can lead to a recurrence of viral infection pathogens, especially in children.