Distinct roles for type I and type III interferons in virulent human metapneumovirus pathogenesis.

Human metapneumovirus (HMPV) is an important cause of acute lower respiratory infection in children and adults worldwide. There are four genetic subgroups of HMPV and both neutralizing antibodies and T cells contribute to protection. However, little is known about mechanisms of pathogenesis and most published work is based on a few extensively passaged, laboratory-adapted strains of HMPV. In this study, we isolated and characterized a panel of low passage HMPV clinical isolates representing all four genetic subgroups. The clinical isolates exhibited lower levels of in vitro replication compared to a lab-adapted strain. We compared disease phenotypes using a well-established mouse model. Several virulent isolates caused severe weight loss, lung pathology, airway dysfunction, and fatal disease in mice, which was confirmed in three inbred mouse strains. Disease severity did not correlate with lung viral titer, as virulent strains exhibited restricted replication in the lower airway. Virulent HMPV isolates were associated with markedly increased proinflammatory cytokine production and neutrophil influx; however, depletion of neutrophils or genetic ablation of inflammasome components did not reverse disease. Virulent clinical isolates induced markedly increased type I and type III interferon (IFN) secretion in vitro and in vivo. STAT1/2-deficient mice lacking both type I and type III IFN signaling showed reduced disease severity and increased lung viral replication. Inhibition of type I IFN signaling using a blocking antibody or genetic ablation of the type I IFN receptor reduced pathology with minimal effect on viral replication. Conversely, blockade of type III IFN signaling with a neutralizing antibody or genetic ablation of the IFN-lambda receptor had no effect on pathogenesis but restored viral replication. Collectively, these results demonstrate distinct roles for type I and type III IFN in HMPV pathogenesis and immunity.

Efficacy of Systemic Bevacizumab for Recurrent Respiratory Papillomatosis with Pulmonary Involvement.

OBJECTIVES: Pulmonary papillomatosis is a rare but severe manifestation of recurrent respiratory papillomatosis (RRP). Efficacy data of systemic bevacizumab for pulmonary RRP are limited. This study's objective was to characterize disease response of pulmonary RRP to systemic bevacizumab. METHODS: A retrospective review was performed to identify patients with pulmonary RRP seen at three medical institutions. Clinical symptoms, CT findings, and disease response were compared before and after initiation of systemic bevacizumab therapy. Disease response was categorized as complete response, partial response, stabilization, or progression for each subsite involved by papilloma. RESULTS: Of the 12 pulmonary RRP patients treated with systemic bevacizumab, 4 (33.3%) were male, and 11 (91.7%) were juvenile-onset RRP patients. All presented with laryngeal, tracheal, and pulmonary RRP. The median (range) age at first bevacizumab infusion was 48.1 (19.5-70.2) years. Progression to pulmonary malignancy was identified in 3 (25.0%) patients, 2 before initiation of and 1 after complete cessation of bevacizumab therapy. Clinical symptoms such as dyspnea (75.0% vs. 25.0%; p = 0.01) and dysphagia and/or odynophagia (33.3 vs. 0.0%; p = 0.03) were significantly decreased following bevacizumab therapy. Compared with pre-treatment baseline, 9 (75.0%) patients experienced a stable-to-partial response in the lungs to systemic bevacizumab, and 10 (83.3%) experienced partial-to-complete responses in the larynx and trachea. CONCLUSION: Systemic bevacizumab is effective in stabilizing progression in even the most severe cases of RRP, with both a dramatic reduction in laryngeal and tracheal disease as well as a stable-to-partial response of pulmonary involvement in a majority of patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:577-581, 2024.

Retrospective study on the efficacy of monocyte distribution width (MDW) as a screening test for COVID-19.

BACKGROUND: Pathogenic genetic testing for coronavirus disease 2019 (COVID-19) can detect viruses with high sensitivity; however, there are several challenges. In the prevention, testing, and treatment of COVID-19, more effective, safer, and convenient methods are desired. We evaluated the possibility of monocyte distribution width (MDW) as an infection biomarker in COVID-19 testing. METHODS: The efficacy of MDW as a screening test for COVID-19 was retrospectively assessed in 80 patients in the COVID-19 group and 232 patients in the non-COVID-19 group (141 patients with acute respiratory infection, 19 patients with nonrespiratory infection, one patient with a viral infection, 11 patients who had received treatment for COVID-19, one patient in contact with COVID-19 patients, and 59 patients with noninfectious disease). RESULTS: The median MDW in 80 patients in the COVID-19 group was 23.3 (17.2-33.6), and the median MDW in 232 patients in the non-COVID-19 group was 19.0 (13.6-30.2) (P < 0.001). When the COVID-19 group was identified using the MDW cut-off value of 21.3 from the non-COVID-19 group, the area under the curve (AUC) was 0.844, and the sensitivity and specificity were 81.3% and 78.2%, respectively. Comparison of MDW by severity between the COVID-19 group and patients with acute respiratory infection in the non-COVID-19 group showed that MDW was significantly higher in the COVID-19 group for all mild, moderate I, and moderate II disease. CONCLUSIONS: MDW (cut-off value: 21.3) may be used as a screening test for COVID-19 in fever outpatients. Trial registration This study was conducted after being approved by the ethics committee of National Hospital Organization Omuta National Hospital (Approval No. 3-19). This study can be accessed via https://omuta.hosp.go.jp/files/000179721.pdf .

Respiratory infections and type 1 diabetes: Potential roles in pathogenesis.

Among the environmental factors associated with type 1 diabetes (T1D), viral infections of the gut and pancreas has been investigated most intensely, identifying enterovirus infections as the prime candidate trigger of islet autoimmunity (IA) and T1D development. However, the association between respiratory tract infections (RTI) and IA/T1D is comparatively less known. While there are significant amounts of epidemiological evidence supporting the role of respiratory infections in T1D, there remains a paucity of data characterising infectious agents at the molecular level. This gap in the literature precludes the identification of the specific infectious agents driving the association between RTI and T1D. Furthermore, the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on the development of IA/T1D remains undeciphered. Here, we provide a comprehensive overview of the evidence to date, implicating RTIs (viral and non-viral) as potential risk factors for IA/T1D.

A case report of inherited surfactant protein deficiency: unknown cause of diffuse infiltrative diseases in Tunisia.

INTRODUCTION: Children's Interstitial Lung Diseases (cHILD) are a heterogeneous group of rare respiratory diseases. Their common characteristics are gas exchange abnormalities and diffuse pulmonary infiltrates on chest imaging. This group includes inherited surfactant protein deficiency (ISPD), a little-known etiology in Tunisia. CASE PRESENTATION: A 22-month-old boy was referred to investigate recurrent respiratory infections. He had polypnea, cyanosis, finger clubbing, pectus carinatum, intercostal retraction, and bilateral crackles on pulmonary auscultation. The chest imaging revealed a diffuse ground-glass appearance consistent with cHILD. Lung biopsy was suggestive of ISPD. The infant was mainly treated with intravenous corticosteroids. At the age of nine, he was still dependent on oxygen but had better exercise tolerance. CONCLUSION: This case showed that recurrent respiratory infections can hide cHILD which may be related to ISPD, particularly in infants. A better knowledge of this disease was necessary to start specific treatment. Early management would lead to better prognosis.

Recapitulating infection, thermal sensitivity and antiviral treatment of seasonal coronaviruses in human airway organoids.

BACKGROUND: Human seasonal coronaviruses usually cause mild upper-respiratory tract infection, but severe complications can occur in specific populations. Research into seasonal coronaviruses is limited and robust experimental models are largely lacking. This study aims to establish human airway organoids (hAOs)-based systems for seasonal coronavirus infection and to demonstrate their applications in studying virus-host interactions and therapeutic development. METHODS: The infections of seasonal coronaviruses 229E, OC43 and NL63 in 3D cultured hAOs with undifferentiated or differentiated phenotypes were tested. The kinetics of virus replication and production was profiled at 33 °C and 37 °C. Genome-wide transcriptome analysis by RNA sequencing was performed in hAOs under various conditions. The antiviral activity of molnupiravir and remdesivir, two approved medications for treating COVID19, was tested. FINDINGS: HAOs efficiently support the replication and infectious virus production of seasonal coronaviruses 229E, OC43 and NL63. Interestingly, seasonal coronaviruses replicate much more efficiently at 33 °C compared to 37 °C, resulting in over 10-fold higher levels of viral replication. Genome-wide transcriptomic analyses revealed distinct patterns of infection-triggered host responses at 33 °C compared to 37 °C temperature. Treatment of molnupiravir and remdesivir dose-dependently inhibited the replication of 229E, OC43 and NL63 in hAOs. INTERPRETATION: HAOs are capable of modeling 229E, OC43 and NL63 infections. The intriguing finding that lower temperature resembling that in the upper respiratory tract favors viral replication may help to better understand the pathogenesis and transmissibility of seasonal coronaviruses. HAOs-based innovative models shall facilitate the research and therapeutic development against seasonal coronavirus infections. FUNDING: This research is supported by funding of a VIDI grant (No. 91719300) from the Netherlands Organization for Scientific Research and the Dutch Cancer Society Young Investigator Grant (10140) to Q.P., and the ZonMw COVID project (114025011) from the Netherlands Organization for Health Research and Development to R.R.

Prospective, Multi-Center Study of the Anatomic Distribution of Recurrent Respiratory Papillomatosis.

OBJECTIVES/HYPOTHESIS: To create a model of the anatomic distribution, recurrence, and growth patterns of recurrent respiratory papillomatosis (RRP). STUDY DESIGN: Prospective, multi-institutional cohort study. METHODS: Adult patients with a diagnosis of RRP evaluated between August 1, 2018 and February 1, 2021 at six participating centers were invited to enroll. At each office or operating room encounter, laryngologists recorded the location and size of RRP lesions using a 22-region schematic. A generalized linear mixed effects model was used to compare region variations in lesion prevalence and recurrence. RESULTS: The cohort comprised 121 patients: 74% were male, 81% had been diagnosed with adult-onset RRP, and a plurality (34%) had undergone 0 to 3 RRP interventions prior to enrollment. Across the study period, the odds of a lesion occurring in the glottis was significantly higher (odds ratio [OR]: 26.51; 95% confidence interval [CI]: 11.76-59.75, P < .001) compared with all other areas of the larynx and trachea. Within the true vocal folds, the membranous vocal folds had significantly higher odds (OR: 6.16; 95% CI: 2.66-14.30, P < .001) of lesion occurrence compared to the cartilaginous vocal folds. Despite these strong trends in lesion distribution, there were no differences in the odds of lesion recurrence, growth, or in the time to recurrence, between anatomic subsites. CONCLUSIONS: RRP lesions are most likely to occur in the glottis, particularly the membranous vocal folds, compared with other regions of the larynx or trachea. However, all lesions demonstrate similar behavior with respect to recurrence, growth, and time to recurrence regardless of anatomic location. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:2403-2411, 2022.

mBodyMap: a curated database for microbes across human body and their associations with health and diseases.

mBodyMap is a curated database for microbes across the human body and their associations with health and diseases. Its primary aim is to promote the reusability of human-associated metagenomic data and assist with the identification of disease-associated microbes by consistently annotating the microbial contents of collected samples using state-of-the-art toolsets and manually curating the meta-data of corresponding human hosts. mBodyMap organizes collected samples based on their association with human diseases and body sites to enable cross-dataset integration and comparison. To help users find microbes of interest and visualize and compare their distributions and abundances/prevalence within different body sites and various diseases, the mBodyMap database is equipped with an intuitive interface and extensive graphical representations of the collected data. So far, it contains a total of 63 148 runs, including 14 401 metagenomes and 48 747 amplicons related to health and 56 human diseases, from within 22 human body sites across 136 projects. Also available in the database are pre-computed abundances and prevalence of 6247 species (belonging to 1645 genera) stratified by body sites and diseases. mBodyMap can be accessed at: https://mbodymap.microbiome.cloud.

Host-to-Host Group A Streptococcus Transmission Causes Infection of the Lamina Propria but Not Epithelium of the Upper Respiratory Tract in MyD88-Deficient Mice.

To understand protective immune responses against the onset of group A Streptococcus respiratory infection, we investigated whether MyD88 KO mice were susceptible to acute infection through transmission. After commingling with mice that had intranasal group A Streptococcus (GAS) inoculation, MyD88-/- recipient mice had increased GAS loads in the nasal cavity and throat that reached a mean throat colonization of 6.3 × 106 CFU/swab and mean GAS load of 5.2 × 108 CFU in the nasal cavity on day 7. Beyond day 7, MyD88-/- recipient mice became moribund, with mean 1.6 × 107 CFU/swab and 2.5 × 109 CFU GAS in the throat and nasal cavity, respectively. Systemic GAS infection occurred a couple of days after the upper respiratory infection. GAS infects the lip, the gingival sulcus of the incisor teeth, and the lamina propria of the turbinate but not the nasal cavity and nasopharyngeal tract epithelia, and C57BL/6J recipient mice had no or low levels of GAS in the nasal cavity and throat. Direct nasal GAS inoculation of MyD88-/- mice caused GAS infection, mainly in the lamina propria of the turbinate. In contrast, C57BL/6J mice with GAS inoculation had GAS bacteria in the nasal cavity but not in the lamina propria of the turbinates. Thus, MyD88-/- mice are highly susceptible to acute and lethal GAS infection through transmission, and MyD88 signaling is critical for protection of the respiratory tract lamina propria but not nasal and nasopharyngeal epithelia against GAS infection.

Transcriptomic Landscape of Gene Expression Profiles and Pathways in Juvenile-Onset Recurrent Respiratory Papillomatosis Tumor Tissues and Human Papillomavirus 6 and 11 E6- and E7-Overexpressing Head and Neck Squamous Cell Carcinoma Cell Lines.

Juvenile-onset recurrent respiratory papillomatosis (JORRP) is the most common benign laryngeal neoplasm in children and is considered to be primarily caused by human papillomavirus (HPV) types 6 and 11. In the present study, we performed RNA sequencing (RNA-seq) of 8 tumors and 4 adjacent nontumor tissues to explore the transcriptional profiles of JORRP tumors. A total of 1,151 upregulated genes involved in the interleukin-17 (IL-17) signaling pathway and 1,620 downregulated genes involved in dysregulated inflammatory responses were reported. Immunohistochemistry (IHC) assays confirmed the upregulation of IL-17C in JORRP tumors compared with paired adjacent nontumor tissues. Real-time PCR (RT-PCR) assays showed positive correlations between CXCL1 (CXC chemokine ligands 1) and CXCL8 and the Derkay Clinic Score of JORRP patients. We further overexpressed the HPV6 or HPV11 E6 and E7 oncogenes in SNU-1076 head and neck squamous cell carcinoma (HNSCC) cell lines and carried out RNA-seq. We found that HPV6-E6-E7 gene overexpression resulted in only 16 upregulated genes and 1 downregulated gene; however, HPV11-E6-E7 gene overexpression resulted in 1,776 upregulated genes and 461 downregulated genes compared with the control cell lines. The differentially expressed genes (DEGs) of HPV11-E6-E7 gene overexpression were positively enriched in the DNA replication-related terms by Gene Ontology (GO) analysis and the IL-17 signaling pathway by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Taken together, our present findings revealed IL-17 signaling pathway-related gene profiles that might contribute to disease pathogenesis and that the HPV11 E6 and E7 oncogenes promote disease progression by enhancing tumor growth and activating the IL-17 signaling pathway in JORRP patients. IMPORTANCE Juvenile-onset recurrent respiratory papillomatosis (JORRP) is primarily caused by human papillomavirus 6 (HPV6) and HPV11 infection; however, the gene signatures of tumors are currently less understood. In the present study, we performed RNA sequencing and found upregulated genes associated with the IL-17 signaling pathway and downregulated genes associated with inflammatory-related pathways. Further RNA sequencing was performed in HPV6-E6-E7- or HPV11-E6-E7-overexpressing SNU-1076 HNSCC cells lines to explore the potential pathogenic molecular mechanisms of HPV virus. We found that HPV11-E6-E7 overexpression resulted in gene expression related to DNA replication and the IL-17 signaling pathway. Our results suggested enriched that the IL-17 signaling pathway resulting from HPV11 infection might contribute to JORRP pathogenesis.

The Impact of Laryngopharyngeal Reflux on Occurrence and Clinical Course of Recurrent Respiratory Papillomatosis.

OBJECTIVES/HYPOTHESIS: Laryngopharyngeal reflux (LPR) has been proposed both as a trigger for recurrent respiratory papillomatosis (RRP) onset and as a factor favoring an aggressive clinical course. STUDY DESIGN: In this prospective study, 106 participants were recruited within a period of 24 months at the Department of Otorhinolaryngology and Cervicofacial Surgery, University Medical Centre Ljubljana. METHODS: This study compared a group of RRP patients (N = 36) with a group of LPR patients (N = 28) and a group of healthy participants (N = 42) based on Reflux Symptom Index (RSI), Reflux Finding Scores (RFS), and saliva analyses (pH, pepsin concentration, bile acid concentration, and pepsin enzymatic activity). RESULTS: The RRP group compared to the LPR group showed a statistically significant difference only in RSI and RFS scores, while the RRP group compared to healthy controls showed significantly higher values in all tested parameters (RSI score, RFS, saliva pH, pepsin concentration, bile acids concentration, pepsin enzymatic activity). CONCLUSIONS: LPR is common in RRP patients and significantly more prevalent compared to healthy controls. Our results show that saliva analyses are a better office-based tool than RSI questionnaires and RFS scores for diagnosing LPR in RRP patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:619-625, 2022.

Antibiotic susceptibility patterns of bacterial isolates of patients with upper respiratory tract infections

Abstract To evaluate the antibiotic susceptibility patterns in URTIs reporting to tertiary hospitals of Lahore. A cross-sectional study employing 259 culture sensitivity reports obtained from tertiary care hospitals of Lahore. Using SPSS, descriptive statistics were used to estimate frequencies and percentages. In URTIs, S. aureus (5%) was the frequent gram-positive isolate followed by MRSA (1.5%) and MSSA (1.5%), while P. aeruginosa (15.8%) was the prevalent gram-negative isolate followed by Klebsiella (13.1%) and E. coli (6.9%). Against P. aeruginosa, ceftazidime (7.7%), cefuroxime/ceftriaxone (4.6%), amoxicillin (4.3%) and ciprofloxacin (4.2%), were tested resistant, while imipenem (11.2%), ciprofloxacin (9.2%), amikacin (9.2%), meropenem/ levofloxacin/gentamicin (8.1%) and piptaz (6.9%) were found sensitive. Against Klebsiella, carbepenems (7.3%), amikacin (6.5%), ciprofloxacin (5.4%) and gentamicin (5%) were tested sensitive, whereas, ceftazidime (8.5%), ceftriaxone (5.8%), cefaclor (5.5%), ampicillin (4.6%), co-amoxiclave (4.2%) and ciftazidime/ciprofloxacin (3.8%) were found resistant. Overall, imipenem (35%), meropenem (30.8%) and amikacin (31.9%) were the three most sensitive antibiotics, while ceftazidime (25.4%), ceftriaxone (19.2%) and ampicillin (18.5%) were the three most resistant antibiotics. Data suggested that P.aeruginosa and Klebsiella, were the most frequent bacterial isolates in URTIs of Lahore. These isolates were resistant to ampicillin, cefuroxime and ceftazidime, but were sensitive to carbapenem and aminoglycosides

A comparison of host response strategies to distinguish bacterial and viral infection.

OBJECTIVES: Compare three host response strategies to distinguish bacterial and viral etiologies of acute respiratory illness (ARI). METHODS: In this observational cohort study, procalcitonin, a 3-protein panel (CRP, IP-10, TRAIL), and a host gene expression mRNA panel were measured in 286 subjects with ARI from four emergency departments. Multinomial logistic regression and leave-one-out cross validation were used to evaluate the protein and mRNA tests. RESULTS: The mRNA panel performed better than alternative strategies to identify bacterial infection: AUC 0.93 vs. 0.83 for the protein panel and 0.84 for procalcitonin (P<0.02 for each comparison). This corresponded to a sensitivity and specificity of 92% and 83% for the mRNA panel, 81% and 73% for the protein panel, and 68% and 87% for procalcitonin, respectively. A model utilizing all three strategies was the same as mRNA alone. For the diagnosis of viral infection, the AUC was 0.93 for mRNA and 0.84 for the protein panel (p<0.05). This corresponded to a sensitivity and specificity of 89% and 82% for the mRNA panel, and 85% and 62% for the protein panel, respectively. CONCLUSIONS: A gene expression signature was the most accurate host response strategy for classifying subjects with bacterial, viral, or non-infectious ARI.

A multilevel analysis of the social determinants associated with symptoms of acute respiratory infection among preschool age children in Pakistan: A population-based survey.

BACKGROUND: As advocated by WHO in "Closing the Health Gap in a Generation", dramatic differences in child health are closely linked to degrees of social disadvantage, both within and between communities. Nevertheless, research has not examined whether child health inequalities include, but are not confined to, worse acute respiratory infection (ARI) symptoms among the socioeconomic disadvantaged in Pakistan. In addition to such disadvantages as the child's gender, maternal education, and household poverty, the present study also examined the linkages between the community environment and ARI symptoms among Pakistan children under five. Furthermore, we have assessed gender contingencies related to the aforementioned associations. METHODS: Using data from the nationally representative 2017-2018 Pakistan Demographic and Health Survey, a total of 11,908 surviving preschool age children (0-59 months old) living in 561 communities were analyzed. We employed two-level multilevel logistic regressions to model the relationship between ARI symptoms and individual-level and community-level social factors. RESULTS: The social factors at individual and community levels were found to be significantly associated with an increased risk of the child suffering from ARI symptoms. A particularly higher risk was observed among girls who resided in urban areas (AOR = 1.42; p<0.01) and who had a birth order of three or greater. DISCUSSIONS: Our results underscore the need for socioeconomic interventions in Pakistan that are targeted at densely populated households and communities within urban areas, with a particular emphasis on out-migration, in order to improve unequal economic underdevelopment. This could be done by targeting improvements in socio-economic structures, including maternal education.

The Trend of TIM3 Expression on T Cells in Patients With Nontuberculous Mycobacterial Lung Disease: From Immune Cell Dysfunction to Clinical Severity.

Background: The incidence of nontuberculous mycobacterial lung disease (NTM-LD) is increasing worldwide. Immune exhaustion has been reported in NTM-LD, but T-cell immunoglobulin and mucin domain-containing protein 3 (TIM3), a co-inhibitory receptor on T cells, has been scarcely studied. Methods: Patients with NTM-LD and healthy controls were prospectively recruited from July 2014 to August 2019 at three tertiary referral centers in Taiwan. We examined TIM3 expression on the T cells from the participants using flow cytometry. TIM3 expression was analyzed for different disease statuses and after treatment. The apoptosis and cytokine profiles were analyzed according to the TIM3 expression. Results: Among enrolled subjects (47 patients and 46 controls), TIM3 on CD4+ cells (6.44% vs. 4.12%, p = 0.028) and CD8+ cells (18.47% vs. 9.13%, p = 0.003) were higher in NTM-LD patients than in the controls. The TIM3 level on CD4+ and CD8+ T cells was positively associated with T-cell apoptosis in the NTM-LD patients. In stimulating peripheral blood mononuclear cells using PMA plus ionomycin, a high TIM3 level on T cells correlated with low interleukin-2 and tumor necrosis factor-alpha (TNF-α) on CD4+ cells and interferon-gamma and TNF-α on CD8+ T cells. For clinical manifestation, low body mass index (BMI), positive sputum acid-fast smear, and high radiographic score correlated with high TIM3 expression on T cells. After NTM treatment, TIM3+ decreased significantly on CD4+ and CD8+ T cells. Conclusions: In patients with NTM-LD, TIM3+ expression increased over CD4+ and CD8+ T cells and correlated with cell apoptosis and specific cytokine attenuation. Clinically, TIM3+ T cells increased in patients with low BMI, high disease extent, and high bacilli burden but decreased after treatment.

Evaluation of the SARS-CoV-2 positivity ratio and upper respiratory tract viral load among asymptomatic individuals screened before hospitalization or surgery in Flanders, Belgium.

INTRODUCTION: The incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections in the Belgian community is mainly estimated based on test results of patients with coronavirus disease (COVID-19)-like symptoms. The aim of this study was to investigate the evolution of the SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) positivity ratio and distribution of viral loads within a cohort of asymptomatic patients screened prior hospitalization or surgery, stratified by age category. MATERIALS/METHODS: We retrospectively studied data on SARS-CoV-2 real-time RT-PCR detection in respiratory tract samples of asymptomatic patients screened pre-hospitalization or pre-surgery in nine Belgian hospitals located in Flanders over a 12-month period (1 April 2020-31 March 2021). RESULTS: In total, 255925 SARS-CoV-2 RT-PCR test results and 2421 positive results for which a viral load was reported, were included in this study. An unweighted overall SARS-CoV-2 real-time RT-PCR positivity ratio of 1.27% was observed with strong spatiotemporal differences. SARS-CoV-2 circulated predominantly in 80+ year old individuals across all time periods except between the first and second COVID-19 wave and in 20-30 year old individuals before the second COVID-19 wave. In contrast to the first wave, a significantly higher positivity ratio was observed for the 20-40 age group in addition to the 80+ age group compared to the other age groups during the second wave. The median viral load follows a similar temporal evolution as the positivity rate with an increase ahead of the second wave and highest viral loads observed for 80+ year old individuals. CONCLUSION: There was a high SARS-CoV-2 circulation among asymptomatic patients with a predominance and highest viral loads observed in the elderly. Moreover, ahead of the second COVID-19 wave an increase in median viral load was noted with the highest overall positivity ratio observed in 20-30 year old individuals, indicating they could have been the hidden drivers of this wave.

Pediatric thalassemic patients have higher incidence of asthma: A nationwide population-based retrospective cohort study.

INTRODUCTION: Patients with hemoglobinopathies have been reported to have higher rates of pulmonary complications. Few studies have investigated the association between thalassemia and asthma in children. METHODS: We used the data of one million individuals randomly selected from the Registry for Beneficiaries of the National Health Insurance Research Database. One thalassemic child was matched with four control children without thalassemia according to sex, birth year, birth season, prematurity, and previous enteroviral infection. RESULTS: A total of 800 hundred thalassemic children and 3200 controls were included. Children with thalassemia had higher rates of developing asthma (41.81 vs 25.70 per 1000 person-years, P < 0.001) than the non-thalassemia controls with an adjusted hazard ratio of 1.37 (95% confidence interval [CI] = 1.19-1.58). Boys in the thalassemia cohort had a significantly higher adjusted incidence hazard ratio (IRR) of asthma than those in the non-thalassemia cohort (adjusted IRR = 1.45, 95% CI = 1.02-1.73). The risk of atopic and nonatopic asthma was higher in the thalassemia cohort than in the non-thalassemia cohort (IRR = 1.3, 1.61, respectively). CONCLUSIONS: Children with thalassemia were more likely to develop asthma. More attention should be paid to the early diagnosis of asthma and prevention of asthma attacks.

Layer-by-layer coated hybrid nanoparticles with pH-sensitivity for drug delivery to treat acute lung infection.

Bacteria-induced acute lung infection (ALI) is a severe burden to human health, which could cause acute respiratory distress syndrome (ARDS) and kill the patient rapidly. Therefore, it is of great significance to develop effective nanomedicine and therapeutic approach to eliminate the invading bacteria in the lung and manage ALI. In this study, we design a layer-by-layer (LbL) liposome-polymer hybrid nanoparticle (HNP) with a pH-triggered drug release profile to deliver antibiotics for the eradication of bacteria to treat ALI. The liposome is prepared by the lipid film hydration method with a homogenous hydrodynamic diameter and low polydispersity index (PDI). The antibiotic spectinomycin is efficiently loaded into the liposomal core through the pH-gradient method. The pH-sensitive polycationic polymer poly(ß-amino ester) (PBAE) and polyanionic sodium alginate (NaAIg) layers are decorated on the surface of liposome in sequence via electrostatic interaction, resulting in spectinomycin-loaded layer-by-layer hybrid nanoparticles (denoted as Spe@HNPs) which have reasonable particle size, high stability, prolonged circulation time, and pH-triggered drug release profile. The in vitro results demonstrate that Spe@HNPs can efficiently induce the death of bacteria with low minimum inhibitory concentration (MIC) against Staphylococcus aureus (S. aureus) and drug-resistant MRSA BAA40 strains. The in vivo results reveal that Spe@HNPs can eradicate the invading MRSA BAA40 with improved antimicrobial efficacy and low side-effect for ALI treatment. This study not only reports a promising nanomedicine but also provides an effective method to prepare nanoplatforms for drug delivery and controlled release.

Metabolic Modifications by Common Respiratory Viruses and Their Potential as New Antiviral Targets.

Respiratory viruses are known to be the most frequent causative mediators of lung infections in humans, bearing significant impact on the host cell signaling machinery due to their host-dependency for efficient replication. Certain cellular functions are actively induced by respiratory viruses for their own benefit. This includes metabolic pathways such as glycolysis, fatty acid synthesis (FAS) and the tricarboxylic acid (TCA) cycle, among others, which are modified during viral infections. Here, we summarize the current knowledge of metabolic pathway modifications mediated by the acute respiratory viruses respiratory syncytial virus (RSV), rhinovirus (RV), influenza virus (IV), parainfluenza virus (PIV), coronavirus (CoV) and adenovirus (AdV), and highlight potential targets and compounds for therapeutic approaches.

What are the determinants of childhood infections in India's peri-urban slums? A case study of eight cities.

BACKGROUND: Respiratory Tract Infections (RTIs) and Gastro-Intestinal (GI) infections are the leading causes of child mortality and morbidity. This study investigates the associations between the individual, household and slum-level determinants of children's health and vulnerability to RTIs and GI infections in peri-urban slums in India; an area of research interest at the Childhood Infections and Pollution Consortium. METHODS: The 2015-16 Indian National Family Health Survey was used for data analysis on children aged 0-5 years. NFHS-4 includes data on slums in eight Indian cities, including Delhi, Meerut, Kolkata, Indore, Mumbai, Nagpur, Hyderabad, Chennai. The outcome variables, having fever and cough (FeCo) and diarrhoea in the last two weeks, were used to define the phenotype of infections; for this analysis fever and cough were measures of RTIs and diarrhoea was used to measure GI infections. Exposures considered in this study include variables at the individual, household and slum level and were all informed by existing literature. Multilevel models were used to estimate the association between exposures and outcomes variables; a prior of Cauchy distribution with a scale of 2.5 was selected when building the multilevel logistic models. RESULTS: The total sample size of the number of children included in the analysis was n = 1,424. Data was imputed to account for missingness, and the original and imputed sample showing similar distributions. Results showed that diarrhoea and FeCo were both found to be more present in younger children than older children by a few months. In fixed effects, the odds of developing FeCo were higher if the mother perceives the child was born smaller than average (AOR 4.41, 1.13-17.17, P<0.05) at individual level. On the other hand, the odds of the diarrhoea outcome were lower if the child was older (AOR 0.97, 0.96-0.98, P<0.05) at individual level, and household's water source was public tap or standpipe (AOR 0.54, 0.31-0.96, P<0.05) at household level. CONCLUSION: The determinants of health, both social and related to health care, at all levels demonstrated linkages to child morbidity in RTIs and GI infections. The empirical evidence highlights the need for contextualised ideas at each level, including one health approach when designing interventions to improve child health.