scholarly journals Hydrating the Respiratory Tract: An Alternative Explanation Why Masks Lower Severity of COVID-19 Disease

2020 ◽  
Author(s):  
Joseph M. Courtney ◽  
Ad Bax
Keyword(s):  
Relative Humidity ◽  
Respiratory Tract ◽  
Disease Severity ◽  
Severe Disease ◽  
Absolute Humidity ◽  
Indoor Environments ◽  
Mucosal Layer ◽  
Lower Severity ◽  
Environmental Air ◽  
Desorption Cycle

AbstractSeasonality of respiratory diseases has been linked, among other factors, to low outdoor absolute humidity and low relative humidity in indoor environments, which increase evaporation of water in the mucosal layer lining the respiratory tract. We demonstrate that normal breathing results in an absorption-desorption cycle inside facemasks, where super-saturated air is absorbed by the mask fibers during expiration, followed by evaporation during inspiration of dry environmental air. For double-layered cotton masks, which have considerable heat capacity, the temperature of inspired air rises above room temperature, and the effective increase in relative humidity can exceed 100%. We propose that the recently reported, disease-attenuating effect of generic facemasks is dominated by the strong humidity increase of inspired air.SIGNIFICANCE STATEMENTFacemasks are the most widely used tool for mitigating the spread of the COVID-19 pandemic. Decreased disease severity by the wearer has also been linked to the use of cloth facemasks. This well-documented finding is surprising considering that such masks are poor at filtering the smallest aerosol particles, which can reach the lower respiratory tract and have been associated with severe disease. We show that facemasks strongly increase the effective humidity of inhaled air, thereby promoting hydration of the respiratory epithelium which is known to be beneficial to the immune system. Increased humidity of inspired air could be an alternate explanation for the now well-established link between mask wearing and lower disease severity.

scholarly journals Predicting Disease Severity and Viral Spread of H5N1 Influenza Virus in Ferrets in the Context of Natural Exposure Routes

2015 ◽  
Vol 90 (4) ◽  
pp. 1888-1897 ◽  
Author(s):  
Kathryn M. Edenborough ◽  
Suzanne Lowther ◽  
Karen Laurie ◽  
Manabu Yamada ◽  
Fenella Long ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Respiratory Tract ◽  
Disease Severity ◽  
Severe Disease ◽  
Upper Respiratory Tract ◽  
H5n1 Influenza Virus ◽  
Viral Spread ◽  
H5n1 Influenza ◽  
Upper Respiratory ◽  
The Brain

ABSTRACTAlthough avian H5N1 influenza virus has yet to develop the capacity for human-to-human spread, the severity of the rare cases of human infection has warranted intensive follow-up of potentially exposed individuals that may require antiviral prophylaxis. For countries where antiviral drugs are limited, the World Health Organization (WHO) has developed a risk categorization for different levels of exposure to environmental, poultry, or human sources of infection. While these take into account the infection source, they do not account for the likely mode of virus entry that the individual may have experienced from that source and how this could affect the disease outcome. Knowledge of the kinetics and spread of virus after natural routes of exposure may further inform the risk of infection, as well as the likely disease severity. Using the ferret model of H5N1 infection, we compared the commonly used but artificial inoculation method that saturates the total respiratory tract (TRT) with virus to upper respiratory tract (URT) and oral routes of delivery, those likely to be encountered by humans in nature. We show that there was no statistically significant difference in survival rate with the different routes of infection, but the disease characteristics were somewhat different. Following URT infection, viral spread to systemic organs was comparatively delayed and more focal than after TRT infection. By both routes, severe disease was associated with early viremia and central nervous system infection. After oral exposure to the virus, mild infections were common suggesting consumption of virus-contaminated liquids may be associated with seroconversion in the absence of severe disease.IMPORTANCERisks for human H5N1 infection include direct contact with infected birds and frequenting contaminated environments. We used H5N1 ferret infection models to show that breathing in the virus was more likely to produce clinical infection than swallowing contaminated liquid. We also showed that virus could spread from the respiratory tract to the brain, which was associated with end-stage disease, and very early viremia provided a marker for this. With upper respiratory tract exposure, infection of the brain was common but hard to detect, suggesting that human neurological infections might be typically undetected at autopsy. However, viral spread to systemic sites was slower after exposure to virus by this route than when virus was additionally delivered to the lungs, providing a better therapeutic window. In addition to exposure history, early parameters of infection, such as viremia, could help prioritize antiviral treatments for patients most at risk of succumbing to infection.

scholarly journals Signatures of COVID-19 severity and immune response in the respiratory tract microbiome

2021 ◽  
Author(s):  
Carter Merenstein ◽  
Guanxiang Liang ◽  
Samantha A Whiteside ◽  
Ana G Cobián-Güemes ◽  
Madeline S Merlino ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Disease Severity ◽  
Mononuclear Cells ◽  
Severe Disease ◽  
16S Rrna Gene Sequencing ◽  
Viral Disease ◽  
Patient Specific ◽  
Rrna Gene ◽  
Peripheral Blood Mononuclear ◽  
Microbiome Composition

Rationale: Viral infection of the respiratory tract can be associated with propagating effects on the airway microbiome, and microbiome dysbiosis may influence viral disease. Objective: To define the respiratory tract microbiome in COVID-19 and relationship disease severity, systemic immunologic features, and outcomes. Methods and Measurements: We examined 507 oropharyngeal, nasopharyngeal and endotracheal samples from 83 hospitalized COVID-19 patients, along with non-COVID patients and healthy controls. Bacterial communities were interrogated using 16S rRNA gene sequencing, commensal DNA viruses Anelloviridae and Redondoviridae were quantified by qPCR, and immune features were characterized by lymphocyte/neutrophil (L/N) ratios and deep immune profiling of peripheral blood mononuclear cells (PBMC). Main Results: COVID-19 patients had upper respiratory microbiome dysbiosis, and greater change over time than critically ill patients without COVID-19. Diversity at the first time point correlated inversely with disease severity during hospitalization, and microbiome composition was associated with L/N ratios and PBMC profiles in blood. Intubated patients showed patient-specific and dynamic lung microbiome communities, with prominence of Staphylococcus. Anelloviridae and Redondoviridae showed more frequent colonization and higher titers in severe disease. Machine learning analysis demonstrated that integrated features of the microbiome at early sampling points had high power to discriminate ultimate level of COVID-19 severity. Conclusions: The respiratory tract microbiome and commensal virome are disturbed in COVID-19, correlate with systemic immune parameters, and early microbiome features discriminate disease severity. Future studies should address clinical consequences of airway dysbiosis in COVID-19, possible use as biomarkers, and role of bacterial and viral taxa identified here in COVID-19 pathogenesis.

scholarly journals SARS-CoV-2 in Urine May Predict a Severe Evolution of COVID-19

2021 ◽  
Vol 10 (18) ◽  
pp. 4061
Author(s):  
Alessandro Perrella ◽  
Mario Brita ◽  
Francesco Coletta ◽  
Simona Cotena ◽  
GiamPaola De Marco ◽  
...  
Keyword(s):  
Intensive Care ◽  
Respiratory Tract ◽  
Intensive Care Units ◽  
Disease Severity ◽  
Death Rate ◽  
Severe Disease ◽  
Serum Levels ◽  
C Reactive Protein ◽  
Disease Evolution ◽  
Reactive Protein

We hypothesized that the spread of SARS-CoV-2 in urine during a severe COVID-19 infection may be the expression of the worsening disease evolution. Therefore, the aim of this study was to verify if the COVID-19 disease severity is related to the viral presence in urine samples. We evaluated the clinical evolution in acute COVID-19 patients admitted in the sub-intensive care and intensive care units between 28 of December 2020 and 15th of February 2021 and being positive for SARS-CoV-2 RNA in the respiratory tract, including repeated endotracheal aspirates (ETA), sputum, nasopharyngeal swabs (NPS) and urine. We found that those subjects with SARS-COV-2 in the urine at admittance (8 out of 60 eligible patients) had a more severe disease than those with negative SARS-CoV-2 in urine. Further, they showed an increase in fibrinogen and (C-reactive Protein) CRP serum levels, requiring mechanic ventilation. Of those with positive SARS-CoV-2 in the urine, 50% died. According to our preliminary results, it seems that the presence of SARS-CoV-2 in the urine characterizes patients with a more severe disease and is also related to a higher death rate.

scholarly journals Serum C-Reactive Protein and Interleukin-6 Levels as Biomarkers for Disease Severity and Clinical Outcomes in Patients with Idiopathic Granulomatous Mastitis

2021 ◽  
Vol 10 (10) ◽  
pp. 2077
Author(s):  
Yi-Min Huang ◽  
Chiao Lo ◽  
Chiao-Feng Cheng ◽  
Cheng-Hsun Lu ◽  
Song-Chou Hsieh ◽  
...  
Keyword(s):  
Disease Severity ◽  
Severe Disease ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Serum Biomarkers ◽  
Healthy Controls ◽  
Granulomatous Mastitis ◽  
C Reactive Protein ◽  
Idiopathic Granulomatous Mastitis ◽  
Reactive Protein

Idiopathic granulomatous mastitis (IGM) is a rare inflammatory breast disease mimicking breast cancer. Limited research has been conducted on the application of serum biomarkers. This study aims to investigate the association of serum biomarkers with disease severity in patients with IGM. From November 2011 to March 2020, medical records of patients with IGM were reviewed. Serum cytokine levels were measured in patients and healthy controls between July 2018 and March 2020. A total of 41 patients with histologically proven IGM were found. Serum interleukin (IL)-6 level was significantly higher in patients with IGM (n = 11) than healthy controls (n = 7). Serum IL-6 and C-reactive protein (CRP) levels were significantly higher in patients with severe disease than mild and moderate disease. Serum IL-6 (Spearman’s ρ = 0.855; p < 0.001) and CRP (Spearman’s ρ = 0.838; p = 0.001) levels were associated with time to resolution. A higher serum CRP level was associated with a longer time to resolution (B = 0.322; p < 0.001) in multiple linear regression analysis. Serum IL-6 and CRP levels can be used as biomarkers for the evaluation of disease severity in IGM. IL-6 may play a crucial role in the immunopathology of IGM.

scholarly journals Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio and Their Role as Predictors of Disease Severity of Coronavirus Disease 2019 (COVID-19)

2021 ◽  
Author(s):  
Rohit Jain ◽  
Arun Gopal ◽  
Basant Kumar Pathak ◽  
Sourya Sourabh Mohakuda ◽  
TVSVGK Tilak ◽  
...  
Keyword(s):  
Disease Severity ◽  
Complete Blood Count ◽  
Wide Spectrum ◽  
Statistical Significance ◽  
Severe Disease ◽  
Neutrophil To Lymphocyte Ratio ◽  
Screening Tools ◽  
Platelet To Lymphocyte Ratio ◽  
Lymphocyte Ratio ◽  
Time Of Admission

Abstract Context Due to the wide spectrum of clinical illness in coronavirus disease 2019 (COVID-19) patients, it is important to stratify patients into severe and nonsevere categories. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been evaluated rapidly by a few studies worldwide for its association with severe disease, but practically none have been conducted in the Indian population. This study was undertaken to examine the role of NLR and PLR in predicting severe disease in Indian patients. Objectives The objective was to study the association of NLR and PLR observed at the time of admission with maximum disease severity during hospitalization and to study their role in predicting disease severity. Material and Methods A total of 229 COVID-19 patients were admitted at the center during the study period. After applying inclusion and exclusion criteria, 191 patients were included in the study. The demographic, clinical, and laboratory (complete blood count, NLR, and PLR) data of all patients were obtained at the time of admission. Maximum disease severity of all patients was assessed during hospitalization. Statistical Analysis Chi-square and Mann–Whitney U tests were used to assess statistical significance. Receiver operating characteristic curve (ROC) was plotted for NLR and PLR to estimate the cutoff values and sensitivity and specificity using Youden’s index for predicting severe disease. Logistic regression analysis was used to estimate the odds ratios (OR) and 95% confidence intervals. Results Mean NLR and PLR were significantly higher in severe patients (NLR = 7.41; PLR = 204) compared with nonsevere patients (NLR = 3.30; PLR = 121). ROC analysis showed that NLR, in comparison to PLR, had a higher area under the curve (AUC) of 0.779, with a larger OR of 1.237 and cutoff of 4.1, and showed 69% sensitivity and 78% specificity in predicting severe disease. Cut off for PLR was 115.3, which showed 79% sensitivity and 62% specificity in predicting severe disease. Conclusion NLR and PLR, both showing acceptable AUCs, can be used as screening tools to predict disease severity. However, NLR was a better predictor of disease severity.

scholarly journals CD169/SIGLEC1 is expressed on circulating monocytes in COVID-19 and expression levels are associated with disease severity

Infection ◽  
2021 ◽  
Author(s):  
Jan-Moritz Doehn ◽  
Christoph Tabeling ◽  
Robert Biesen ◽  
Jacopo Saccomanno ◽  
Elena Madlung ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Disease Severity ◽  
Clinical Studies ◽  
Viral Infections ◽  
Severe Disease ◽  
Type I Interferons ◽  
Type I ◽  
Interferon Signaling ◽  
Expression Levels

AbstractCoronavirus disease 2019 (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Type I interferons are important in the defense of viral infections. Recently, neutralizing IgG auto-antibodies against type I interferons were found in patients with severe COVID-19 infection. Here, we analyzed expression of CD169/SIGLEC1, a well described downstream molecule in interferon signaling, and found increased monocytic CD169/SIGLEC1 expression levels in patients with mild, acute COVID-19, compared to patients with severe disease. We recommend further clinical studies to evaluate the value of CD169/SIGLEC1 expression in patients with COVID-19 with or without auto-antibodies against type I interferons.

scholarly journals Informing the public health response to COVID-19: a systematic review of risk factors for disease, severity, and mortality

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Flook ◽  
C. Jackson ◽  
E. Vasileiou ◽  
C. R. Simpson ◽  
M. D. Muckian ◽  
...  
Keyword(s):  
Public Health ◽  
Risk Factors ◽  
Systematic Review ◽  
At Risk ◽  
Risk Factor ◽  
Disease Severity ◽  
Severe Disease ◽  
Public Health Response ◽  
Wide Range ◽  
Multivariable Analyses

Abstract Background Severe Acute Respiratory Syndrome coronavirus-2 (SARS-CoV-2) has challenged public health agencies globally. In order to effectively target government responses, it is critical to identify the individuals most at risk of coronavirus disease-19 (COVID-19), developing severe clinical signs, and mortality. We undertook a systematic review of the literature to present the current status of scientific knowledge in these areas and describe the need for unified global approaches, moving forwards, as well as lessons learnt for future pandemics. Methods Medline, Embase and Global Health were searched to the end of April 2020, as well as the Web of Science. Search terms were specific to the SARS-CoV-2 virus and COVID-19. Comparative studies of risk factors from any setting, population group and in any language were included. Titles, abstracts and full texts were screened by two reviewers and extracted in duplicate into a standardised form. Data were extracted on risk factors for COVID-19 disease, severe disease, or death and were narratively and descriptively synthesised. Results One thousand two hundred and thirty-eight papers were identified post-deduplication. Thirty-three met our inclusion criteria, of which 26 were from China. Six assessed the risk of contracting the disease, 20 the risk of having severe disease and ten the risk of dying. Age, gender and co-morbidities were commonly assessed as risk factors. The weight of evidence showed increasing age to be associated with severe disease and mortality, and general comorbidities with mortality. Only seven studies presented multivariable analyses and power was generally limited. A wide range of definitions were used for disease severity. Conclusions The volume of literature generated in the short time since the appearance of SARS-CoV-2 has been considerable. Many studies have sought to document the risk factors for COVID-19 disease, disease severity and mortality; age was the only risk factor based on robust studies and with a consistent body of evidence. Mechanistic studies are required to understand why age is such an important risk factor. At the start of pandemics, large, standardised, studies that use multivariable analyses are urgently needed so that the populations most at risk can be rapidly protected. Registration This review was registered on PROSPERO as CRD42020177714.

scholarly journals Optical fibre Sensor for Simultaneous Temperature and Relative Humidity Measurement: Towards Absolute Humidity Evaluation

2021 ◽  
pp. 130154
Author(s):  
Chenyang He ◽  
Serhiy Korposh ◽  
Ricardo Correia ◽  
Liangliang Liu ◽  
Barrie R. Hayes-Gill ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Optical Fibre ◽  
Absolute Humidity ◽  
Humidity Measurement ◽  
Optical Fibre Sensor ◽  
Fibre Sensor

scholarly journals The Role of the Respiratory Microbiome and Viral Presence in Lower Respiratory Tract Infection Severity in the First Five Years of Life

2021 ◽  
Vol 9 (7) ◽  
pp. 1446
Author(s):  
Ivo Hoefnagels ◽  
Josephine van de Maat ◽  
Jeroen J.A. van Kampen ◽  
Annemarie van Rossum ◽  
Charlie Obihara ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Disease Severity ◽  
Lower Respiratory Tract ◽  
Influenza A ◽  
Pediatric Population ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Detection Rates ◽  
Tract Infections ◽  
Respiratory Microbiome

Lower respiratory tract infections (LRTIs) in children are common and, although often mild, a major cause of mortality and hospitalization. Recently, the respiratory microbiome has been associated with both susceptibility and severity of LRTI. In this current study, we combined respiratory microbiome, viral, and clinical data to find associations with the severity of LRTI. Nasopharyngeal aspirates of children aged one month to five years included in the STRAP study (Study to Reduce Antibiotic prescription in childhood Pneumonia), who presented at the emergency department (ED) with fever and cough or dyspnea, were sequenced with nanopore 16S-rRNA gene sequencing and subsequently analyzed with hierarchical clustering to identify respiratory microbiome profiles. Samples were also tested using a panel of 15 respiratory viruses and Mycoplasma pneumoniae, which were analyzed in two groups, according to their reported virulence. The primary outcome was hospitalization, as measure of disease severity. Nasopharyngeal samples were isolated from a total of 167 children. After quality filtering, microbiome results were available for 54 children and virology panels for 158 children. Six distinct genus-dominant microbiome profiles were identified, with Haemophilus-, Moraxella-, and Streptococcus-dominant profiles being the most prevalent. However, these profiles were not found to be significantly associated with hospitalization. At least one virus was detected in 139 (88%) children, of whom 32.4% had co-infections with multiple viruses. Viral co-infections were common for adenovirus, bocavirus, and enterovirus, and uncommon for human metapneumovirus (hMPV) and influenza A virus. The detection of enteroviruses was negatively associated with hospitalization. Virulence groups were not significantly associated with hospitalization. Our data underlines high detection rates and co-infection of viruses in children with respiratory symptoms and confirms the predominant presence of Haemophilus-, Streptococcus-, and Moraxella-dominant profiles in a symptomatic pediatric population at the ED. However, we could not assess significant associations between microbiome profiles and disease severity measures.

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