Face masks effectively limit the probability of SARS-CoV-2 transmission

Photosensitive Oxidase Mimics for Spontaneous and Sustainable Pathogen Disinfection in Personal Protective Equipment

The development of personal protective equipment (PPE) is essential to control the spread of infectious diseases. However, traditional PPE has significant drawbacks, such as a lack of antibacterial capacity and nonreusability, which may result in direct or indirect secondary infections. Herein, we propose an octahedral (Fe-O6) Fe-gallate (Fe-GA) metal-organic framework nanozyme with light-enhanced oxidase-like (OXD-like) activity and extend the use onto nonwoven fabric (Fe-GA/NWF) by hot pressing. Specifically, visible-light-mediated carrier migration and the activity of the OXD-like species synergistically enhance the production of reactive oxygen species, achieving superior antibacterial effects without the addition of any chemical additives. In this case, Fe-GA/NWF spontaneously inactivates over 99.9% of real microbial aerosols and demonstrates excellent mechanical properties, reusability (15 cycles), and biocompatibility. Moreover, Fe-GA/NWF can be used as an ideal antibacterial platform for KN95 masks and protective clothing and can be extended to other substrates. This work provides a promising strategy to develop self-antibacterial PPE in complex environments.

Trends of respiratory viruses and factors associated with severe acute respiratory infection in patients presenting at a university hospital: a 6-year retrospective study across the COVID-19 pandemic

Background

The COVID-19 pandemic significantly disrupted the epidemiology of respiratory viruses, altering seasonal patterns and reducing circulation. While recovery trends have been observed, factors associated with severe acute respiratory infections (SARIs) during pre- and post-pandemic periods remain underexplored in middle-income countries.

Objective

This study aimed to analyze the trends in respiratory virus circulation and identify factors associated with SARI in patients attending a tertiary care university hospital in western Mexico over a six-year period spanning the pre-pandemic, pandemic, and post-pandemic phases.

Methods

A retrospective study was conducted using data from 19,088 symptomatic patients tested for respiratory viruses between 2018 and 2024. Viral trends were analyzed through interrupted time series (ITS) modeling, incorporating locally estimated scatterplot smoothing (LOESS) and raw positivity rates. Additionally, ITS analysis was performed to evaluate temporal changes in SARI proportions across different phases of the pandemic. Multivariate logistic regression models were applied to determine independent risk factors for SARI across different time periods.

Results

During the pandemic (2020-2021), respiratory virus positivity rates significantly declined, particularly for influenza, which experienced a sharp reduction but rebounded post-2022. Respiratory syncytial virus (RSV) demonstrated a delayed resurgence, whereas other respiratory viruses exhibited heterogeneous rebound patterns. ITS modeling of SARI proportions revealed a significant pre-pandemic increasing trend, followed by a slower rise during the pandemic, and a sharp post-pandemic drop in early 2022, before resuming an upward trajectory. Among older adults (>65 years), a marked increase in SARI was observed at the beginning of the pandemic, while younger groups showed more stable patterns. Logistic regression identified advanced age, male sex, cardiovascular disease, obesity, and immunosuppression as major risk factors for SARI, while vaccination consistently showed a protective effect across all periods and subgroups.

Conclusion

The COVID-19 pandemic induced persistent shifts in respiratory virus circulation, disrupting seasonal dynamics and modifying the burden of SARI. The findings underscore the importance of continuous surveillance, targeted vaccination programs, and early diagnostics to mitigate severe outcomes. These results highlight the need for adaptive public health strategies in middle-income countries to address evolving respiratory disease threats.

Structural inequalities exacerbate infection disparities

During the COVID-19 pandemic, the world witnessed a disproportionate infection rate among marginalized and low-income groups. Despite empirical evidence suggesting that structural inequalities in society contribute to health disparities, there has been little attempt to offer a computational and theoretical explanation to establish its plausibility and quantitative impact. Here, we focus on two aspects of structural inequalities: wealth inequality and social segregation. Our computational model demonstrates that (a) due to the inequality in self-quarantine ability, the infection gap widens between the low-income and high-income groups, and the overall infected cases increase, (b) social segregation between different socioeconomic status (SES) groups intensifies the disease spreading rates, and (c) the second wave of infection can emerge due to a false sense of safety among the medium and high SES groups. By performing two data-driven analyses, one on the empirical network and economic data of 404 metropolitan areas of the United States and one on the daily Covid-19 data of the City of Chicago, we verify that higher segregation leads to an increase in the overall infection cases and higher infection inequality across different ethnic/socioeconomic groups. These findings together demonstrate that reducing structural inequalities not only helps decrease health disparities but also reduces the spread of infectious diseases overall.

COVID-19 related complications

The COVID-19 pandemic has significantly impacted global healthcare systems, revealed vulnerabilities and prompted a re-evaluation of medical practices. Acute complications from the virus, including cardiovascular and neurological issues, have underscored the necessity for timely medical interventions. Advances in diagnostic methods and personalized therapies have been pivotal in mitigating severe outcomes. Additionally, Long COVID has emerged as a complex challenge, affecting various body systems and leading to respiratory, cardiovascular, neurological, psychological, and musculoskeletal problems. This broad spectrum of complications highlights the importance of multidisciplinary management approaches that prioritize therapy, rehabilitation, and patient-centered care. Vulnerable populations such as paediatric patients, pregnant women, and immunocompromised individuals face unique risks and complications, necessitating continuous monitoring and tailored management strategies to reduce morbidity and mortality associated with COVID-19.

Analysis of inoculation strategies during COVID-19 pandemic with an agent-based simulation approach

BACKGROUND

The severity of recent Coronavirus (COVID-19) pandemics has revealed the importance of development of inoculation strategies in case of limited vaccine availability. Authorities have implemented inoculation strategies based on perceived risk factors such as age and existence of other chronic health conditions for survivability from the disease. However, various other factors can be considered for identifying the preferred inoculation strategies depending on the vaccine availability and disease spread levels. This study explores the effectiveness of inoculating different groups of population in case of various vaccine availabilities and disease spread levels by means of some performance metrics namely: Attack Rate (AR), Death Rate (DR) and Hospitalization Rate (HR).

METHOD

In this study we have implemented a highly detailed Agent-Based Simulation (ABS) model that extends classical SEIR Model by including five more additional states: Asymptomatic (A), Quarantine (Q), Hospitalized (H), Dead (D) and Immune (M) which can be used as a decision support tool to prioritize the groups of the population inoculated. The approach employs the modelling of daily mobility of individuals, their interactions and transmission of virus among individuals. The population is heterogeneously clustered according to age, family size, work status, transportation and leisure preferences with 17 different groups in order to find the most appropriate one to inoculate. Three different Disease Spread Levels (DSL) (low, mid, high) are experimented with four different Vaccine Available Percentages (VAP) (25%, 50%, 75% and 85%) with a total of 84 scenarios.

RESULTS

As the benchmark, under the No Vaccine case Attack Rate, Hospitalization Rate, and Death Rate goes as high as 99.53%, 16.96%, and 1.38%, respectively. Corresponding highest performance metrics (rates) are 72.33%, 15.95%, and 1.35% for VAP = 25%; 50.25%, 9.55%, and 0.94% for VAP = 50%; 24.53%, 2.62%, and 0.25% for VAP = 75%; and 11.51%, 0.002%, and 0.08% for VAP = 85%. The results of our study shows that the common practice of inoculation based on the age of individual does not yield the best outcome in terms of performance metrics across all DSL and VAP values. The groups containing workers and students that represent highly interactive individuals, i.e. Group (9, 10), Group (9, 11, 10‾) and Group (9, 10, 11, 12‾) emerge as a commonly recommended choice for inoculation in the majority of cases. As expected, we observe that the higher is the VAP levels the more is the number of alternative inoculation groups.

CONCLUSIONS

Findings of this study present that: (i) inoculation considerably decreases the number of infected individuals, the number of deaths and the number of hospitalized individuals due to the disease, (ii) the best inoculation group/groups with respect to performance metrics varies depending on the vaccine availability percentages and disease spread levels, (iii) simultaneous implementation of both inoculation and precautions like lock-down, social distances and quarantines, yields a stronger impact on disease spread and its consequences.

Role of Gut Microbiota in Long COVID: Impact on Immune Function and Organ System Health

SARS-CoV-2 infection has led to a range of long-lasting symptoms, collectively referred to as long COVID. Current research highlights the critical role of angiotensin-converting enzyme 2 (ACE2) in regulating gut microbiota diversity, vascular function, and homeostasis within the renin-angiotensin system (RAS). ACE2 is utilized by the SARS-CoV-2 virus to enter host cells, but its downregulation following infection contributes to gut microbiota dysbiosis and RAS disruption. These imbalances have been linked to a range of long COVID symptoms, including joint pain, chest pain, chronic cough, fatigue, brain fog, anxiety, depression, myalgia, peripheral neuropathy, memory difficulties, and impaired attention. This review investigates the dysregulation caused by SARS-CoV-2 infection and the long-term effects it has on various organ systems, including the musculoskeletal, neurological, renal, respiratory, and cardiovascular systems. We explored the bidirectional interactions between the gut microbiota, immune function, and these organ systems, focusing on how microbiota dysregulation contributes to the chronic inflammation and dysfunction observed in long COVID symptoms. Understanding these interactions is key for identifying effective therapeutic strategies and interventional targets aimed at mitigating the impact of long COVID on organ health and improving patient outcomes.

Exhaled Breath Analysis: From Laboratory Test to Wearable Sensing

Breath analysis and monitoring have emerged as pivotal components in both clinical research and daily health management, particularly in addressing the global health challenges posed by respiratory and metabolic disorders. The advancement of breath analysis strategies necessitates a multidisciplinary approach, seamlessly integrating expertise from medicine, biology, engineering, and materials science. Recent innovations in laboratory methodologies and wearable sensing technologies have ushered in an era of precise, real-time, and in situ breath analysis and monitoring. This comprehensive review elucidates the physical and chemical aspects of breath analysis, encompassing respiratory parameters and both volatile and non-volatile constituents. It emphasizes their physiological and clinical significance, while also exploring cutting-edge laboratory testing techniques and state-of-the-art wearable devices. Furthermore, the review delves into the application of sophisticated data processing technologies in the burgeoning field of breathomics and examines the potential of breath control in human-machine interaction paradigms. Additionally, it provides insights into the challenges of translating innovative laboratory and wearable concepts into mainstream clinical and daily practice. Continued innovation and interdisciplinary collaboration will drive progress in breath analysis, potentially revolutionizing personalized medicine through entirely non-invasive breath methodology.

A Review on Face Mask Recognition

This review offers a comprehensive and in-depth analysis of face mask detection and recognition technologies, emphasizing their critical role in both public health and technological advancements. Existing detection methods are systematically categorized into three primary classes: feaRture-extraction-and-classification-based approaches, object-detection-models-based methods and multi-sensor-fusion-based methods. Through a detailed comparison, their respective workflows, strengths, limitations, and applicability across different contexts are examined. The review underscores the paramount importance of accurate face mask detection, especially in response to global public health challenges such as pandemics. A central focus is placed on the role of datasets in driving algorithmic performance, addressing key factors, including dataset diversity, scale, annotation granularity, and modality. The integration of depth and infrared data is explored as a promising avenue for improving robustness in real-world conditions, highlighting the advantages of multimodal datasets in enhancing detection capabilities. Furthermore, the review discusses the synergistic use of real-world and synthetic datasets in overcoming challenges such as dataset bias, scalability, and resource scarcity. Emerging solutions, such as lightweight model optimization, domain adaptation, and privacy-preserving techniques, are also examined as means to improve both algorithmic efficiency and dataset quality. By synthesizing the current state of the field, identifying prevailing challenges, and outlining potential future research directions, this paper aims to contribute to the development of more effective, scalable, and robust face mask detection systems for diverse real-world applications.

An agent based simulation of COVID-19 history in Catalonia using extensive real datasets

During the COVID-19 pandemic, effective public policy interventions have been crucial in combating virus transmission, sparking extensive debate on crisis management strategies and emphasizing the necessity for reliable models to inform governmental decisions, particularly at the local level. Leveraging disaggregated socio-demographic microdata, including social determinants, age-specific strata, and mobility patterns, we design a comprehensive network model of Catalonia's population and, through numerical simulation, assess its response to the outbreak of COVID-19 over the two-year period 2020-21. Our findings underscore the critical importance of timely implementation of broad non-pharmaceutical measures and effective vaccination campaigns in curbing virus spread; in addition, the identification of high-risk groups and their corresponding maps of connections within the network paves the way for tailored and more impactful interventions.

Mask Wearers at Risk of Inhaling Respirable Hazards from Leave-On Facial Cosmetics

Previous research has widely overlooked the respiratory risks associated with cosmetic powder, a type of mixed particulate matter with intricate chemical compositions, especially in the context of wearing masks. This study investigated the inhalation risks posed by five face powders, focusing on both particulate matter (minerals and primary microplastics) and soluble components (preservatives and organic UV filters). Wearing masks significantly increased the inhalation risk of face powders, with exposure levels influenced by factors such as particle size, density, and composition. Additionally, different samples demonstrated irregular behavioral patterns when exposed to various human tissue environments. Soluble components analysis revealed that multiple additives dissolved in six body fluids, with a higher degree of release observed in the respiratory tract fluid compared to the digestive tract fluid. The alveoli may serve as a specific target for exposure to organic UV filters due to the solubilization effect of pulmonary surfactants. These findings revealed the importance of considering both particulate matter and soluble components when assessing respiratory and digestive exposure risks from cosmetic powders. Furthermore, understanding the interactions between cosmetic particles and body fluids, as well as potential synergistic toxic effects, is crucial for ensuring the safety of cosmetic products and safeguarding public health.

Implementation of facemask sampling for the detection of infectious individuals with SARS-CoV-2 in high stakes clinical examinations - a feasibility study

Introduction

SARS-CoV-2 may transmit across vaccinated cohorts during practical clinical examinations. We sought to assess the feasibility of facemask sampling (FMS) to identify individuals emitting SARS-CoV-2 during a mock PACES exam.

Methods

In May 2022 we recruited participants from a mock PACES examination in Leicester, UK. Following a negative lateral flow test assay, all participants wore modified facemasks able to capture exhaled virus during the assessment (FMS). A concomitant upper respiratory tract sample (URTS) was provided prior to FMS. Exposed facemasks were processed by removal and dissolution of sampling matrices fixed within the mask and cycle thresholds values quantified by RT-qPCR. Participants were asked to grade statements regarding the comfort, effort, ethics and communication when providing FMS; laboratory technicians were asked to grade key statements surrounding suitability of samples for processing.

Results

34 participants provided concomitant URTS and FMS during the examination. One participant was positive for SARS-CoV-2, with a cycle threshold value of 22.5 on URTS, but negative (no viral RNA detected) on FMS; no transmission to others was identified from this individual. Participants responded positively to statements regarding FMS describing all four domains; however, 69% of participants felt that a positive result from FMS alone was insufficient for diagnosis and that further tests were required. All but one FMS sample was suitable for processing.

Discussion

FMS during PACES exams are acceptable among participants and samples provided are suitable for processing. Our results demonstrate feasibility of FMS within practical examination settings and support the further assessment of FMS as a scalable tool that can be compared with URTS to identify those who are infectious.

Comparing strategies for the mitigation of SARS-CoV-2 airborne infection risk in tiered auditorium venues

The COVID-19 pandemic demonstrated that reliable risk assessment of venues is still challenging and resulted in the indiscriminate closure of many venues worldwide. Therefore, this study used an experimental, numerical and analytical approach to investigate the airborne transmission risk potential of differently ventilated, sized and shaped venues. The data were used to assess the magnitude of effect of various mitigation measures and to develop recommendations. Here we show that, in general, positions in the near field of an emission source were at high risk, while the risk of infection from positions in the far field varied depending on the ventilation strategy. Occupancy, airflow rate, residence time, virus variants, activity level and face masks affected the individual and global infection risk in all venues. The global infection risk was lowest for the displacement ventilation case, making it the most effective ventilation strategy for keeping airborne transmission and the number of secondary cases low, compared to mixing or natural ventilation.

Ladders and stairs: how the intervention ladder focuses blame on individuals and obscures systemic failings and interventions

Introduced in 2007 by the Nuffield Council on Bioethics, the intervention ladder has become an influential tool in bioethics and public health policy for weighing the justification for interventions and for weighing considerations of intrusiveness and proportionality. However, while such considerations are critical, in its focus on these factors, the ladder overemphasises the role of personal responsibility and the importance of individual behaviour change in public health interventions. Through a study of vaccine hesitancy and vaccine mandates among healthcare workers, this paper investigates how the ladder obscures systemic factors such as the social determinants of health. In overlooking these factors, potentially effective interventions are left off the table and the intervention ladder serves to divert attention away from key issues in public health. This paper, therefore, proposes a replacement for the intervention ladder-the intervention stairway. By broadening the intervention ladder to include systemic factors, the stairway ensures relevant interventions are not neglected merely due to the framing of the issue. Moreover, it more accurately captures factors influencing individual health as well as allocations of responsibility for improving these factors.

Back to Basics: The Diagnostic Value of a Complete Blood Count in the Clinical Management of COVID-19

Since the beginning of the COVID-19 pandemic, scientists have struggled significantly to understand the complexity of COVID-19 pathophysiology. COVID-19 has demonstrated a notoriously unpredictable clinical course. This unpredictability constituted a significant obstacle to clinicians in predicting the disease course among COVID-19 patients, more specifically, in predicting who would develop severe cases and possibly die from the infection. This brief report aims to assess the diagnostic value of using a complete blood count (CBC) and applying high-dimensional analysis, i.e., principal component analysis (PCA), on it to differentiate between patients with mild and severe COVID-19 infection. The data of 855 patients were retrieved from multiple centres in Saudi Arabia. Descriptive statistics, such as counts, percentages, and medians (interquartile ranges) were used to describe patients' characteristics and CBC parameters. Analytical statistics, such as the Mann-Whitney U test, were used to compare between survivors and non-survivors. PCA was applied using the CBC parameters, and the results were compared between survivors and non-survivors. Patients in this study had a median age of 41, with an almost equal ratio of men to women. Most participants were Saudis, and non-survivors were 13.22% of the total cohort. The median values of all CBC indices were within reference ranges; however, some statistically significant differences were observed between survivors and non-survivors. Non-survivors had lower hemoglobin levels and lower hematocrit, lymphocyte, and eosinophil counts but higher WBC and neutrophil counts compared to survivors. PCA on the CBC results of survivors yielded a significantly different profile than non-survivors, indicating the possibility of its use in the context of COVID-19. The diagnostic value of CBC in the clinical management of COVID-19 should be utilized in clinical guidelines for managing COVID-19 cases.

Droplet Micro-Sensor and Detection of Respiratory Droplet Transmission

Droplet transmission is the primary infection route for respiratory diseases like COVID-19 and influenza, but small and low-cost wearable droplet detection devices are a significant challenge. Herein, a respiratory droplet micro-sensor based on graphene oxide quantum dots (GOQDs) assembled onto SiO2 microspheres by the nebulized natural deposition is presented. Benefiting from the energy dissipation of the microsphere to droplets, the sensor can detect droplets as far as 2 m from coughing. With this sensor, droplet signal variations caused by some factors like distance, speech, angles, and wind directions are explored, and the effectiveness of different protective measures in preventing droplet transmission is evaluated. This droplet detection technology is expected to be utilized for the development of personal detection and protection devices against infectious respiratory diseases.

The effect of mobility reductions on infection growth is quadratic in many cases

Stay-at-home orders were introduced in many countries during the COVID-19 pandemic, limiting the time people spent outside their home and the attendance of gatherings. In this study, we argue from a theoretical model that in many cases the effect of such stay-at-home orders on incidence growth should be quadratic, and that this statement should also hold beyond COVID-19. That is, a reduction of the out-of-home duration to, say, 70% of its original value should reduce incidence growth and thus the effective R-value to 70 % · 70 % = 49 % of its original value. We then show that this hypothesis can be substantiated from data acquired during the COVID-19 pandemic by using a multiple regression model to fit a combination of the quadratic out-of-home duration and temperature to the COVID-19 growth multiplier. We finally demonstrate that many other models, when brought to the same scale, give similar reductions of the effective R-value, but that none of these models extend plausibly to an out-of-home duration of zero.

Masks and respirators for prevention of respiratory infections: a state of the science review

SUMMARYThis narrative review and meta-analysis summarizes a broad evidence base on the benefits-and also the practicalities, disbenefits, harms and personal, sociocultural and environmental impacts-of masks and masking. Our synthesis of evidence from over 100 published reviews and selected primary studies, including re-analyzing contested meta-analyses of key clinical trials, produced seven key findings. First, there is strong and consistent evidence for airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Second, masks are, if correctly and consistently worn, effective in reducing transmission of respiratory diseases and show a dose-response effect. Third, respirators are significantly more effective than medical or cloth masks. Fourth, mask mandates are, overall, effective in reducing community transmission of respiratory pathogens. Fifth, masks are important sociocultural symbols; non-adherence to masking is sometimes linked to political and ideological beliefs and to widely circulated mis- or disinformation. Sixth, while there is much evidence that masks are not generally harmful to the general population, masking may be relatively contraindicated in individuals with certain medical conditions, who may require exemption. Furthermore, certain groups (notably D/deaf people) are disadvantaged when others are masked. Finally, there are risks to the environment from single-use masks and respirators. We propose an agenda for future research, including improved characterization of the situations in which masking should be recommended or mandated; attention to comfort and acceptability; generalized and disability-focused communication support in settings where masks are worn; and development and testing of novel materials and designs for improved filtration, breathability, and environmental impact.

Trichome-Like Biomimetic Air Filters via Templated Silicone Nanofilaments

Air pollution threats to human health have increased awareness of the role of filter units in air cleaning applications. As an ideal energy-saving strategy for air filters, the slip effect on nanofiber surfaces can potentially overcome the trade-off between filtration efficiency and pressure drop. However, the potential of the slip effect in nanofibrous structures is significantly limited by the tight nanofiber stacks. In this study, trichome-like biomimetic (TLB) air filters with 3D-templated silicone nanofilaments (average diameter: ≈74 nm) are prepared based on an in situ chemical vapor deposition (CVD) method inspired by plant purification. Theoretical modeling and experimental results indicate that TLB air filters make significant use of the slip effect to overcome the efficiency-resistance tradeoff. The selectable filter class (up to U15, ≈99.9995%) allows TLB air filters to meet various requirements, and their integral filtration performance surpasses that of most commodity air filters, including melt-blown cloth, ePTFE membranes, electrospun mats, and glass fiber paper. The proposed strategy directly transforms commercial filter media and filters into TLB air filters using a bottom-up, one-step approach. As a proof-of-concept, reusable N95 respirators and air purifiers equipped with TLB air filters are fabricated, overcoming the limitations of existing filter designs and fabrication methods.

Wearing masks is easy but taking them off is difficult - A situation in Japan during COVID-19 pandemic and after

Background

Masks are well accepted in Japan, where they were already part of daily life even before the COVID-19 pandemic. Unlike many other countries where mask mandates were lifted as soon as the pandemic was under control, Japan was one of the last countries to ease mask-wearing guidelines. Even after the formal announcement to allow masks-off in mid-March 2023, many Japanese still voluntarily wear masks. In this work, possible reasons for this extreme "mask-affinity" of Japanese people were studied by exploring various information sources including tweets (now known as X posts) and subsequent text-analysis, online news, and medical literature.

Methods

An observational study was conducted based on tweets prospectively collected during 5 months from June 26th, 2022 to November 26th, 2022. Tweets with the hashtag "mask (in Japanese)" were collected weekly via the Twitter application programming interface by using R version 4.0.3 to gauge public opinions. The word clouds to allow intuitive understanding of the key words were drawn from the tokenized text.

Results

The data collection period included the 7th flareups of the newly infected cases i.e. "the 7th surge". In total, 161,592 tweets were collected. Word clouds for 1) before the 7th surge based on 18,000 tweets on June 26th and 2) during/after the 7th surge based on 143,592 tweets between July-November were created with the R package "wordcloud2". The results indicated that the people wanted to take off masks due to the heat in summer, then shifted again toward mask-wearing along with the 7th surge but with a certainly growing "no-mask" sentiment.

Conclusions

Subsequent review of domestic information sources suggested that various factors, not only well-known peer pressure, may have contributed the public's mask affinity in Japan. This work revealed an aspect of Japanese struggle toward adaptation to life in an unexpected pandemic by focusing on masks as our closest daily adjunct over the past 3 years of isolation.Trial registration: not applicable.

From intramuscular to nasal: unleashing the potential of nasal spray vaccines against coronavirus disease 2019

Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected 700 million people worldwide since its outbreak in 2019. The current pandemic strains, including Omicron and its large subvariant series, exhibit strong transmission and stealth. After entering the human body, the virus first infects nasal epithelial cells and invades host cells through the angiotensin-converting enzyme 2 receptor and transmembrane serine protease 2 on the host cell surface. The nasal cavity is an important body part that protects against the virus. Immunisation of the nasal mucosa produces immunoglobulin A antibodies that effectively neutralise viruses. Saline nasal irrigation, a type of physical therapy, can reduce the viral load in the nasal cavity and prevent viral infections to some extent. As a commonly used means to fight SARS-CoV-2, the intramuscular (IM) vaccine can induce the human body to produce a systemic immune response and immunoglobulin G antibody; however, the antibody is difficult to distribute to the nasal mucosa in time and cannot achieve a good preventive effect. Intranasal (IN) vaccines compensate for the shortcomings of IM vaccines, induce mucosal immune responses, and have a better effect in preventing infection. In this review, we discuss the nasal defence barrier, the harm caused by SARS-CoV-2, the mechanism of its invasion into host cells, nasal cleaning, IM vaccines and IN vaccines, and suggest increasing the development of IN vaccines, and use of IN vaccines as a supplement to IM vaccines.

Persistent pollution of genetic materials in a typical laboratory environment

From the onset of coronavirus disease (COVID-19) pandemic, there are concerns regarding the disease spread and environmental pollution of biohazard since studies on genetic engineering flourish and numerous genetic materials were used such as the nucleic acid test of the severe acute respiratory syndrome coronavirus (SARS-CoV-2). In this work, we studied genetic material pollution in an institute during a development cycle of plasmid, one of typical genetic materials, with typical laboratory settings. The pollution source, transmission routes, and pollution levels in laboratory environment were examined. The Real-Time quantitative- Polymerase Chain Reaction results of all environmental mediums (surface, aerosol, and liquid) showed that a targeted DNA segment occurred along with routine experimental operations. Among the 79 surface and air samples collected in the genetic material operation, half of the environment samples (38 of 79) are positive for nucleic acid pollution. Persistent nucleic acid contaminations were observed in all tested laboratories and spread in the public area (hallway). The highest concentration for liquid and surface samples were 1.92 × 108 copies/uL and 5.22 × 107 copies/cm2, respectively. Significant amounts of the targeted gene (with a mean value of 74 copies/L) were detected in the indoor air of laboratories utilizing centrifuge devices, shaking tables, and cell homogenizers. Spills and improper disposal of plasmid products were primary sources of pollution. The importance of establishing designated experimental zones, employing advanced biosafety cabinets, and implementing highly efficient cleaning systems in laboratories with lower biosafety levels is underscored. SYNOPSIS: STATEMENT. Persistent environmental pollutions of genetic materials are introduced by typical experiments in laboratories with low biosafety level.

Versatile Antibacterial and Antioxidant Bacterial Cellulose@Nanoceria Biotextile: Application in Reusable Antimicrobial Face Masks

Despite considerable interest in medical and pharmaceutical fields, there remains a notable absence of functional textiles that concurrently exhibit antibacterial and antioxidant properties. Herein, a new composite fabric constructed using nanostructured bacterial cellulose (BC) covalently-linked with cerium oxide nanoparticles (BC@CeO2NPs) is introduced. The synthesis of CeO2NPs on the BC is performed via a microwave-assisted, in situ chemical deposition technique, resulting in the formation of mixed valence Ce3+/Ce4+ CeO2NPs. This approach ensures the durability of the composite fabric subjected to multiple washing cycles. The Reactive oxygen species (ROS) scavenging activity of CeO2NPs and their rapid and efficient eradication of >99% model microbes, such as Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus remain unaltered in the composite. To demonstrate the feasibility of incorporating the fabric in marketable products, antimicrobial face masks are fabricated with filter layers made of BC@CeO2NPs cross-linked with propylene or cotton fibers. These masks exhibit complete inhibition of bacterial growth in the three bacterial strains, improved breathability compared to respirator masks and enhanced filtration efficiency compared to single-use surgical face masks. This study provides valuable insights into the development of functional BC@CeO2NPs biotextiles in which design can be extended to the fabrication of medical dressings and cosmetic products with combined antibiotic, antioxidant and anti-inflammatory activities.

The airborne transmission of viruses causes tight transmission bottlenecks

The transmission bottleneck describes the number of viral particles that initiate an infection in a new host. Previous studies have used genome sequence data to suggest that transmission bottlenecks for influenza and SARS-CoV-2 involve few viral particles, but the general principles of virus transmission are not fully understood. Here we show that, across a broad range of circumstances, tight transmission bottlenecks are a simple consequence of the physical process of airborne viral transmission. We use mathematical modelling to describe the physical process of the emission and inhalation of infectious particles, deriving the result that that the great majority of transmission bottlenecks involve few viral particles. While exceptions to this rule exist, the circumstances needed to create these exceptions are likely very rare. We thus provide a physical explanation for previous inferences of bottleneck size, while predicting that tight transmission bottlenecks prevail more generally in respiratory virus transmission.

Bioinspired Structures Made of Silicone Nanofilaments for Upcycling Waste Masks to Reusable N95 Respirators

The increasing demand for personal protective equipment such as single-use masks has led to large amounts of nondegradable plastic waste, aggravating economic and environmental burdens. This study reports a simple and scalable approach for upcycling waste masks via a chemical vapor deposition technique, realizing a trichome-like biomimetic (TLB) N95 respirator with superhydrophobicity (water contact angle ≥150°), N95-level protection, and reusability. The TLB N95 respirator comprising templated silicone nanofilaments with an average diameter of ∼150 nm offers N95-level protection and breathability comparable to those of commercial N95 respirators. The TLB N95 respirator can still maintain its N95-level protection against particulate matter and viruses after 10 disinfection treatment cycles (i.e., ultraviolet irradiation, microwave irradiation, dry heating, and autoclaving), demonstrating durable reusability. The proposed strategy provides new insight into upcycle waste masks, breaking the existing design and preparation concept of reusable masks.

Estimated public health impact of concurrent mask mandate and vaccinate-or-test requirement in Illinois, October to December 2021

BACKGROUND

Facing a surge of COVID-19 cases in late August 2021, the U.S. state of Illinois re-enacted its COVID-19 mask mandate for the general public and issued a requirement for workers in certain professions to be vaccinated against COVID-19 or undergo weekly testing. The mask mandate required any individual, regardless of their vaccination status, to wear a well-fitting mask in an indoor setting.

METHODS

We used Illinois Department of Public Health's COVID-19 confirmed case and vaccination data and investigated scenarios where masking and vaccination would have been reduced to mimic what would have happened had the mask mandate or vaccine requirement not been put in place. The study examined a range of potential reductions in masking and vaccination mimicking potential scenarios had the mask mandate or vaccine requirement not been enacted. We estimated COVID-19 cases and hospitalizations averted by changes in masking and vaccination during the period covering October 20 to December 20, 2021.

RESULTS

We find that the announcement and implementation of a mask mandate are likely to correlate with a strong protective effect at reducing COVID-19 burden and the announcement of a vaccinate-or-test requirement among frontline professionals is likely to correlate with a more modest protective effect at reducing COVID-19 burden. In our most conservative scenario, we estimated that from the period of October 20 to December 20, 2021, the mask mandate likely prevented approximately 58,000 cases and 1,175 hospitalizations, while the vaccinate-or-test requirement may have prevented at most approximately 24,000 cases and 475 hospitalizations.

CONCLUSION

Our results indicate that mask mandates and vaccine-or-test requirements are vital in mitigating the burden of COVID-19 during surges of the virus.

An epidemiological modeling framework to inform institutional-level response to infectious disease outbreaks: a Covid-19 case study

Institutions have an enhanced ability to implement tailored mitigation measures during infectious disease outbreaks. However, macro-level predictive models are inefficient for guiding institutional decision-making due to uncertainty in local-level model input parameters. We present an institutional-level modeling toolkit used to inform prediction, resource procurement and allocation, and policy implementation at Clemson University throughout the Covid-19 pandemic. Through incorporating real-time estimation of disease surveillance and epidemiological measures based on institutional data, we argue this approach helps minimize uncertainties in input parameters presented in the broader literature and increases prediction accuracy. We demonstrate this through case studies at Clemson and other university settings during the Omicron BA.1 and BA.4/BA.5 variant surges. The input parameters of our toolkit are easily adaptable to other institutional settings during future health emergencies. This methodological approach has potential to improve public health response through increasing the capability of institutions to make data-informed decisions that better prioritize the health and safety of their communities while minimizing operational disruptions.

Vaccine mandates for prospective versus existing employees: reply to Smith

Employment-based vaccine mandates have worse consequences for existing than prospective employees. Prospective employees are not yet dependent on a particular employment arrangement, so they are better positioned to respond to such mandates. Yet despite this asymmetry in consequences, Smith argues that if vaccine mandates are justified for prospective employees, they are similarly justified for existing employees. This paper responds to Smith's argument. First, Smith holds that bona fide occupational requirements are actions that are necessary for the safe and effective completion of one's job. As such, they apply to existing and prospective employees alike. However, I argue that the existence of effective alternative interventions precludes vaccination from being considered a bona fide occupational requirement under current circumstances. Second, Smith holds that if a requirement is justified for prospective employees, it is justified for existing employees, despite the asymmetry in consequences. However, I argue that since vaccination is not a bona fide requirement, the asymmetry in the harms of mandates experienced by prospective versus existing employees entails an asymmetry in the justification required to mandate vaccination for each group. As such, vaccination can be considered a requirement for prospective employees while not being required for existing employees.

Effects of Face Mask Mandates on COVID-19 Transmission in 51 Countries: Retrospective Event Study

BACKGROUND

The question of the utility of face masks in preventing acute respiratory infections has received renewed attention during the COVID-19 pandemic. However, given the inconclusive evidence from existing randomized controlled trials, evidence based on real-world data with high external validity is missing.

OBJECTIVE

To add real-world evidence, this study aims to examine whether mask mandates in 51 countries and mask recommendations in 10 countries increased self-reported face mask use and reduced SARS-CoV-2 reproduction numbers and COVID-19 case growth rates.

METHODS

We applied an event study approach to data pooled from four sources: (1) country-level information on self-reported mask use was obtained from the COVID-19 Trends and Impact Survey, (2) data from the Oxford COVID-19 Government Response Tracker provided information on face mask mandates and recommendations and any other nonpharmacological interventions implemented, (3) mobility indicators from Google's Community Mobility Reports were also included, and (4) SARS-CoV-2 reproduction numbers and COVID-19 case growth rates were retrieved from the Our World in Data-COVID-19 data set.

RESULTS

Mandates increased mask use by 8.81 percentage points (P=.006) on average, and SARS-CoV-2 reproduction numbers declined on average by -0.31 units (P=.008). Although no significant average effect of mask mandates was observed for growth rates of COVID-19 cases (-0.98 percentage points; P=.56), the results indicate incremental effects on days 26 (-1.76 percentage points; P=.04), 27 (-1.89 percentage points; P=.05), 29 (-1.78 percentage points; P=.04), and 30 (-2.14 percentage points; P=.02) after mandate implementation. For self-reported face mask use and reproduction numbers, incremental effects are seen 6 and 13 days after mandate implementation. Both incremental effects persist for >30 days. Furthermore, mask recommendations increased self-reported mask use on average (5.84 percentage points; P<.001). However, there were no effects of recommendations on SARS-CoV-2 reproduction numbers or COVID-19 case growth rates (-0.06 units; P=.70 and -2.45 percentage points; P=.59). Single incremental effects on self-reported mask use were observed on days 11 (3.96 percentage points; P=.04), 13 (3.77 percentage points; P=.04) and 25 to 27 (4.20 percentage points; P=.048 and 5.91 percentage points; P=.01) after recommendation. Recommendations also affected reproduction numbers on days 0 (-0.07 units; P=.03) and 1 (-0.07 units; P=.03) and between days 21 (-0.09 units; P=.04) and 28 (-0.11 units; P=.05) and case growth rates between days 1 and 4 (-1.60 percentage points; P=.03 and -2.19 percentage points; P=.03) and on day 23 (-2.83 percentage points; P=.05) after publication.

CONCLUSIONS

Contrary to recommendations, mask mandates can be used as an effective measure to reduce SARS-CoV-2 reproduction numbers. However, mandates alone are not sufficient to reduce growth rates of COVID-19 cases. Our study adds external validity to the existing randomized controlled trials on the effectiveness of face masks to reduce the spread of SARS-CoV-2.

Bio-based ionic liquid filter with enhanced electrostatic attraction for outside filtration and inside collection of viral aerosols

Hazardous biological pathogens in the air pose a significant public environmental health concern as infected individuals emit virus-laden aerosols (VLAs) during routine respiratory activities. Mask-wearing is a key preventive measure, but conventional filtration methods face challenges, particularly in high humidity conditions, where electrostatic charge decline increases the risk of infection. This study introduces a bio-based air filter comprising glycine ionic liquids (GILs) and malleable polymer composite (GILP) with high polarity and functional group density, which are wrapped around a melamine-formaldehyde (MF) resin skeleton, forming a conductive, porous GIL functionized ionic network air filter (GILP@MF). When subjected to low voltage, the GILP@MF composite efficiently captures VLAs including nanoscale virus particles through the enhanced electrostatic attraction, especially in facing high humidity bioaerosols exhaled by human body. The filtration/collection efficiency and quality factor can reach 98.3% and 0.264 Pa-1 at 0.1 m s-1, respectively. This innovative filter provides effective VLA protection and offers potential for non-invasive respiratory virus sampling, advancing medical diagnosis efforts.

Reconciling the efficacy and effectiveness of masking on epidemic outcomes

During the COVID-19 pandemic, mask wearing in public settings has been a key control measure. However, the reported effectiveness of masking has been much lower than laboratory measures of efficacy, leading to doubts on the utility of masking. Here, we develop an agent-based model that comprehensively accounts for individual masking behaviours and infectious disease dynamics, and test the impact of masking on epidemic outcomes. Using realistic inputs of mask efficacy and contact data at the individual level, the model reproduces the lower effectiveness as reported in randomized controlled trials. Model results demonstrate that transmission within households, where masks are rarely used, can substantially lower effectiveness, and reveal the interaction of nonlinear epidemic dynamics, control measures and potential measurement biases. Overall, model results show that, at the individual level, consistent masking can reduce the risk of first infection and, over time, reduce the frequency of repeated infection. At the population level, masking can provide direct protection to mask wearers, as well as indirect protection to non-wearers, collectively reducing epidemic intensity. These findings suggest it is prudent for individuals to use masks during an epidemic, and for policymakers to recognize the less-than-ideal effectiveness of masking when devising public health interventions.

[Air pollution, noise and hypertension : Partners in crime]

Air pollution and traffic noise are two important environmental risk factors that endanger health in urban societies and often act together as "partners in crime". Although air pollution and noise often co-occur in urban environments, they have typically been studied separately, with numerous studies documenting consistent effects of individual exposure on blood pressure. In the following review article, we examine the epidemiology of air pollution and noise, especially regarding the cardiovascular risk factor arterial hypertension and the underlying pathophysiology. Both environmental stressors have been shown to lead to endothelial dysfunction, oxidative stress, pronounced vascular inflammation, disruption of circadian rhythms and activation of the autonomic nervous system, all of which promote the development of hypertension and cardiovascular diseases. From a societal and political perspective, there is an urgent need to point out the potential dangers of air pollution and traffic noise in the American Heart Association (AHA)/American College of Cardiology (ACC) prevention guidelines and the European Society of Cardiology (ESC) guidelines on prevention. Therefore, an essential goal for the future is to raise awareness of environmental risk factors as important and, in particular, preventable risk factors for cardiovascular diseases.

Estimating hidden relationships in dynamical systems: Discovering drivers of infection rates of COVID-19

Discovering causal influences among internal variables is a fundamental goal of complex systems research. This paper presents a framework for uncovering hidden relationships from limited time-series data by combining methods from nonlinear estimation and information theory. The approach is based on two sequential steps: first, we reconstruct a more complete state of the underlying dynamical system, and second, we calculate mutual information between pairs of internal state variables to detail causal dependencies. Equipped with time-series data related to the spread of COVID-19 from the past three years, we apply this approach to identify the drivers of falling and rising infections during the three main waves of infection in the Chicago metropolitan region. The unscented Kalman filter nonlinear estimation algorithm is implemented on an established epidemiological model of COVID-19, which we refine to include isolation, masking, loss of immunity, and stochastic transition rates. Through the systematic study of mutual information between infection rate and various stochastic parameters, we find that increased mobility, decreased mask use, and loss of immunity post sickness played a key role in rising infections, while falling infections were controlled by masking and isolation.

Efficacy of facemasks in preventing transmission of COVID-19 in non-healthcare settings: A scoping review

Background

During the COVID-19 pandemic, an abundance of literature relating to the efficacy of face masks on reducing transmission of COVID-19 in non-healthcare settings emerged.

Aim/objective

The aim of this scoping review was to allow the identification of: types of evidence conducted in this area; knowledge gaps and common concepts relating to mask efficacy in non-healthcare settings.

Methods

A comprehensive literature search was conducted in PubMed, CINAHL, MEDLINE, Embase and the Irish Management Institute bibliographic database on December 15th, 2021. All types of face masks were included. Of 722 records, 16 were included after full text screening.

Findings/results

Themes from an adapted model of Howard et al. framework were used to group results and identify common concepts. The grouped thematic results were then applied to the socio-ecological model. This illustrated the multifactorial elements determining the efficacy of masks themselves while also illustrating how other factors such as individual behaviours, social interactions, settings and national policy can influence the degree of the protective effect.

Discussion

The findings from this scoping review indicate that an abundance of experimental literature is available indicating that masks are effective at preventing COVID-19 transmission but their degree of efficacy is impacted by external factors. This review highlights that the quality of the evidence available is low.

Effect of distributing locally produced cloth facemasks on COVID-19-like illness and all-cause mortality-a cluster-randomised controlled trial in urban Guinea-Bissau

Facemasks have been employed to mitigate the spread of SARS-CoV-2. The community effect of providing cloth facemasks on COVID-19 morbidity and mortality is unknown. In a cluster randomised trial in urban Bissau, Guinea-Bissau, clusters (geographical areas with an average of 19 houses), were randomised to an intervention or control arm using computer-generated random numbers. Between 20 July 2020 and 22 January 2021, trial participants (aged 10+ years) living in intervention clusters (n = 90) received two 2-layer cloth facemasks, while facemasks were only distributed later in control clusters (n = 91). All participants received information on COVID-19 prevention. Trial participants were followed through a telephone interview for COVID-19-like illness (3+ symptoms), care seeking, and mortality for 4 months. End-of-study home visits ensured full mortality information and distribution of facemasks to the control group. Individual level information on outcomes by trial arm was compared in logistic regression models with generalised estimating equation-based correction for cluster. Facemasks use was mandated. Facemask use in public areas was assessed by direct observation. We enrolled 39,574 trial participants among whom 95% reported exposure to groups of >20 persons and 99% reported facemasks use, with no difference between trial arms. Observed use was substantially lower (~40%) with a 3%, 95%CI: 0-6% absolute difference between control and intervention clusters. Half of those wearing a facemask wore it correctly. Few participants (532, 1.6%) reported COVID-19-like illness; proportions did not differ by trial arm: Odds Ratio (OR) = 0.81, 95%CI: 0.57-1.15. 177 (0.6%) participants reported consultations and COVID-19-like illness (OR = 0.83, 95%CI: 0.56-1.24); 89 participants (0.2%) died (OR = 1.34, 95%CI: 0.89-2.02). Hence, though trial participants were exposed to many people, facemasks were mostly not worn or not worn correctly. Providing facemasks and messages about correct use did not substantially increase their use and had limited impact on morbidity and mortality. Trial registration: clinicaltrials.gov: NCT04471766.

Hot-Pressing Metal Covalent Organic Frameworks as Personal Protection Films

Effective personal protection is crucial for controlling infectious disease spread. However, commonly used personal protective materials such as disposable masks lack antibacterial/antiviral function and may lead to cross infection. Herein, a polyethylene glycol-assisted solvent-free strategy is proposed to rapidly synthesize a series of the donor-acceptor metal-covalent organic frameworks (MCOFs) (i.e., GZHMU-2, JNM-1, and JNM-2) under air atmosphere and henceforth extend it via in situ hot-pressing process to prepare MCOFs based films with photocatalytic disinfect ability. Best of them, the newly designed GZHMU-2 has a wide absorption spectrum (200 to 1500 nm) and can efficiently produce reactive oxygen species under sunlight irradiation, achieving excellent photocatalytic disinfection performance. After in situ hot-pressing as a film material, the obtained GZHMU-2/NMF can effectively kill E. coli (99.99%), S. aureus (99%), and H1N1 (92.5%), meanwhile possessing good reusability. Noteworthy, the long-term use of a GZHMU-2/NWF-based mask has verified no damage to the living body by measuring the expression of mouse blood routine, lung tissue, and inflammatory factors at the in-vivo level.

Intranasal mask for protecting the respiratory tract against viral aerosols

The spread of many infectious diseases relies on aerosol transmission to the respiratory tract. Here we design an intranasal mask comprising a positively-charged thermosensitive hydrogel and cell-derived micro-sized vesicles with a specific viral receptor. We show that the positively charged hydrogel intercepts negatively charged viral aerosols, while the viral receptor on vesicles mediates the entrapment of viruses for inactivation. We demonstrate that when displaying matched viral receptors, the intranasal masks protect the nasal cavity and lung of mice from either severe acute respiratory syndrome coronavirus 2 or influenza A virus. With computerized tomography images of human nasal cavity, we further conduct computational fluid dynamics simulation and three-dimensional printing of an anatomically accurate human nasal cavity, which is connected to human lung organoids to generate a human respiratory tract model. Both simulative and experimental results support the suitability of intranasal masks in humans, as the likelihood of viral respiratory infections induced by different variant strains is dramatically reduced.

Ingestion and biodegradation of disposable surgical masks by yellow mealworms Tenebrio molitor larvae: Differences in mask layers and effects on the larval gut microbiome

During the COVID-19 pandemic, the usage and production of face masks considerably increased, resulting in large quantities of mask waste accumulating in the natural environment. To investigate whether masks of polypropylene (PP) material could be ingested and degraded by insect worms like PP foam plastic, yellow mealworms were provided with different layers of disposable surgical masks as sole diets for 30 d. Although mask layers, especially the middle layer of melt-blown filter, could be ingested by yellow mealworms, sole mask layer diets had adverse effects on the larval survival and growth. Analyses of Fourier transform infrared spectroscopy, differential scanning calorimeter and thermogravimetric, and gel permeation chromatography demonstrated the changes of functional groups, thermostability and molecular weights in frass compared to original masks, indicating the partial oxidation and degradation of masks. And the depolymerization of the middle layer of masks by yellow mealworms was different from that of other layers. The larval gut bacterial and fungal microbiomes were assessed by Illumina MiSeq, indicating that both of them shifted upon sole layer mask diets. Changes in relative abundances of dominant bacterial and fungal genera demonstrated the strong association between gut microbiome and mask degradation. For instance, unclassified Enterobacteriaceae was closely associated with outer layers degradation. Lactococcus and unclassified Ascomycota were responsible for middle layers degradation, while Lactococcus and Morganella for inner layers degradation. In conclusion, disposable surgical masks of PP material could be ingested and biodegraded by yellow mealworms. The diversities of gut bacterial and fungal microbiomes were associated with the differences in rigid crystalline structures of the layer masks.

Perceptions of Adults With Hearing Loss About the Communication Difficulties Generated by the COVID-19 Preventive Measures: A Qualitative Study

PURPOSE

The COVID-19 pandemic led to the implementation of preventive measures that exacerbated communication difficulties for individuals with hearing loss. This study aims to explore the perception of adults with hearing loss about the communication difficulties caused by the preventive measures and about their experiences with communication 1 year after the adoption of these preventive measures.

METHOD

Individual semistructured interviews were conducted via videoconference with six adults who have hearing loss from the province of Québec, Canada. Data were examined using qualitative content analysis.

RESULTS

The study found that face masks and in-person work (i.e., in opposition to remote work) were important barriers to communication because of hindered lipreading and competing noise in many workplaces. In contrast, preventive measures that allowed visual information transmission (e.g., transparent face masks, fixed plastic partitions) were considered favorable for communication. Communication partners were perceived as playing an important role in communication success with preventive measures: Familiar communication partners improved communication, whereas those with poor attitude or strategies hindered communication. Participants found that videoconferences could provide satisfactory communication but were sometimes hindered by issues such as bad audiovisual quality or too many participants.

CONCLUSIONS

This study identified reduced access to speech reading and lack of general awareness about hearing issues as key barriers to communication during the pandemic. The decreased communication capabilities were perceived to be most problematic at work and during health appointments, and tended to cause frustration, anxiety, self-esteem issues, and social isolation. Suggestions are outlined for current and future public health measures to better consider the experience of people with hearing loss.

Review of pediatric emergency care and the COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) pandemic posed new challenges in health care delivery for patients of all ages. These included inadequate personal protective equipment, workforce shortages, and unknowns related to a novel virus. Children have been uniquely impacted by COVID-19, both from the system of care and socially. In the initial surges of COVID-19, a decrease in pediatric emergency department (ED) volume and a concomitant increase in critically ill adult patients resulted in re-deployment of pediatric workforce to care for adult patients. Later in the pandemic, a surge in the number of critically ill children was attributed to multisystem inflammatory syndrome in children. This was an unexpected complication of COVID-19 and further challenged the health care system. This article reviews the impact of COVID-19 on the entire pediatric emergency care continuum, factors affecting ED care of children with COVID-19 infection, including availability of vaccines and therapeutics approved for children, and pediatric emergency medicine workforce innovations and/or strategies. Furthermore, it provides guidance to emergency preparedness for optimal delivery of care in future health-related crises.

Trends in the numbers of SARS-CoV-2 infections among students: a prospective cohort study comparing students in sports boarding schools with students in day schools during early COVID-19 pandemic

Introduction

During the first months of the COVID pandemic it emerged that facilities where people gather or live together in cohorts, such as nursing homes or schools, were particularly at high risk for becoming hotspots of virus transmission. German political and health institutions responded with far-reaching interventions and preventive strategies to protect the population from infection with SARS-CoV-2. In this context, it remains unclear whether boarding schools for sports particularly pose a risk of infection to their residents.

Methods

In a single-center prospective cohort study, numbers of SARS-CoV-2 infections of students in sports boarding schools (n = 11) vs. students attending regular day schools (n = 22) in the region Freiburg/Hochschwarzwald in Germany were investigated over a period from October 2020 to January 2021 via regular virus and antibody screening (German Clinical Trials Register; Study ID: DRKS00021909). In addition, individual and behavioral risk factors for infection were stratified via questionnaire, which provide an indication of cohort specific risk factors for infection and the success of the implementation of hygiene concepts, as well as other infection prevention strategies, within the respective facilities.

Results

Regarding SARS-CoV-2 infection numbers, the screening detected no significant group difference between sports boarding schools vs. day schools.

Discussion

The study results provide indications that sports boarding schools did not pose an increased risk of infection, assuming that the facilities prevent virus transmissions with appropriate preventive strategies and hygiene measures. In future pandemic scenarios larger-scale and multicenter studies are necessary to achieve more comprehensive epidemiological data in this field.

The burden and dynamics of hospital-acquired SARS-CoV-2 in England

Hospital-based transmission had a dominant role in Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus (SARS-CoV) epidemics1,2, but large-scale studies of its role in the SARS-CoV-2 pandemic are lacking. Such transmission risks spreading the virus to the most vulnerable individuals and can have wider-scale impacts through hospital-community interactions. Using data from acute hospitals in England, we quantify within-hospital transmission, evaluate likely pathways of spread and factors associated with heightened transmission risk, and explore the wider dynamical consequences. We estimate that between June 2020 and March 2021 between 95,000 and 167,000 inpatients acquired SARS-CoV-2 in hospitals (1% to 2% of all hospital admissions in this period). Analysis of time series data provided evidence that patients who themselves acquired SARS-CoV-2 infection in hospital were the main sources of transmission to other patients. Increased transmission to inpatients was associated with hospitals having fewer single rooms and lower heated volume per bed. Moreover, we show that reducing hospital transmission could substantially enhance the efficiency of punctuated lockdown measures in suppressing community transmission. These findings reveal the previously unrecognized scale of hospital transmission, have direct implications for targeting of hospital control measures and highlight the need to design hospitals better equipped to limit the transmission of future high-consequence pathogens.

The impact of COVID-19 shelter-in-place policy responses on excess mortality

As a way of slowing COVID-19 transmission, many countries and U.S. states implemented shelter-in-place (SIP) policies. However, the effects of SIP policies on public health are a priori ambiguous. Using an event study approach and data from 43 countries and all U.S. states, we measure changes in excess deaths following the implementation of COVID-19 shelter-in-place (SIP) policies. We do not find that countries or U.S. states that implemented SIP policies earlier had lower excess deaths. We do not observe differences in excess deaths before and after the implementation of SIP policies, even when accounting for pre-SIP COVID-19 death rates.

Field investigation combined with modeling uncovers the ecological heterogeneity of Aedes albopictus habitats for strategically improving systematic management during urbanization

BACKGROUND

Aedes albopictus is an invasive vector of serious Aedes-borne diseases of global concern. Habitat management remains a critical factor for establishing a cost-effective systematic strategy for sustainable vector control. However, the community-based characteristics of Ae. albopictus habitats in complex urbanization ecosystems are still not well understood.

METHODS

A large-scale investigation of aquatic habitats, involving 12 sites selected as representative of four land use categories at three urbanization levels, was performed in Guangzhou, China during 2015-2017. The characteristics and dynamics of these Ae. albopictus habitats were assessed using habitat-type composition, habitat preference, diversity indexes and the Route index (RI), and the temporal patterns of these indexes were evaluated by locally weighted scatterplot smoothing models. The associations of RI with urbanization levels, land use categories and climatic variables were inferred using generalized additive mixed models.

RESULTS

A total of 1994 potential habitats and 474 Ae. albopictus-positive habitats were inspected. The majority of these habitats were container-type habitats, with Ae. albopictus showing a particularly higher habitat preference for plastic containers, metal containers and ceramic vessels. Unexpectedly, some non-container-type habitats, especially ornamental ponds and surface water, were found to have fairly high Ae. albopictus positivity rates. Regarding habitats, the land use category residential and rural in Jiangpu (Conghua District, Guangzhou) had the highest number of Ae. albopictus habitats with the highest positive rates. The type diversity of total habitats (H-total) showed a quick increase from February to April and peaked in April, while the H-total of positive habitats (H-positive) and RIs peaked in May. RIs mainly increased with the monthly average daily mean temperature and monthly cumulative rainfall. We also observed the accumulation of diapause eggs in the winter and diapause termination in the following March.

CONCLUSIONS

Ecological heterogeneity of habitat preferences of Ae. albopictus was demonstrated in four land use categories at three urbanization levels. The results reveal diversified habitat-type compositions and significant seasonal variations, indicating an ongoing adaptation of Ae. albopictus to the urbanization ecosystem. H-positivity and RIs were inferred as affected by climatic variables and diapause behavior of Ae. albopictus, suggesting that an effective control of overwintering diapause eggs is crucial. Our findings lay a foundation for establishing a stratified systematic management strategy of Ae. albopictus habitats in cities that is expected to complement and improve community-based interventions and sustainable vector management.

Niclosamide as a chemical probe for analyzing SARS-CoV-2 modulation of host cell lipid metabolism

Introduction

SARS-CoV-2 subverts host cell processes to facilitate rapid replication and dissemination, and this leads to pathological inflammation.

Methods

We used niclosamide (NIC), a poorly soluble anti-helminth drug identified initially for repurposed treatment of COVID-19, which activates the cells' autophagic and lipophagic processes as a chemical probe to determine if it can modulate the host cell's total lipid profile that would otherwise be either amplified or reduced during SARS-CoV-2 infection.

Results

Through parallel lipidomic and transcriptomic analyses we observed massive reorganization of lipid profiles of SARS-CoV-2 infected Vero E6 cells, especially with triglycerides, which were elevated early during virus replication, but decreased thereafter, as well as plasmalogens, which were elevated at later timepoints during virus replication, but were also elevated under normal cell growth. These findings suggested a complex interplay of lipid profile reorganization involving plasmalogen metabolism. We also observed that NIC treatment of both low and high viral loads does not affect virus entry. Instead, NIC treatment reduced the abundance of plasmalogens, diacylglycerides, and ceramides, which we found elevated during virus infection in the absence of NIC, resulting in a significant reduction in the production of infectious virions. Unexpectedly, at higher viral loads, NIC treatment also resulted in elevated triglyceride levels, and induced significant changes in phospholipid metabolism.

Discussion

We posit that future screens of approved or new partner drugs should prioritize compounds that effectively counter SARS-CoV-2 subversion of lipid metabolism, thereby reducing virus replication, egress, and the subsequent regulation of key lipid mediators of pathological inflammation.

Revisiting JC virus and progressive multifocal leukoencephalopathy

Since its definition 65 years ago, progressive multifocal leukoencephalopathy (PML) has continued to devastate a growing population of immunosuppressed patients despite major advances in our understanding of the causative JC virus (JCV). Unless contained by the immune system, JCV lyses host oligodendrocytes collateral to its life cycle, leading to demyelination, neurodegeneration, and death. Novel treatments have stagnated in the absence of an animal model while current antiviral agents fail to address the now ubiquitous polyomavirus. In this review, we highlight the established pathogenesis by which JCV infection progresses to PML, highlighting major challenges that must be overcome to eliminate the underlying virus and, therefore, the debilitating disease.

At the crossroads of epidemiology and biology: Bridging the gap between SARS-CoV-2 viral strain properties and epidemic wave characteristics

The COVID-19 pandemic has given rise to numerous articles from different scientific fields (epidemiology, virology, immunology, airflow physics …) without any effort to link these different insights. In this review, we aim to establish relationships between epidemiological data and the characteristics of the virus strain responsible for the epidemic wave concerned. We have carried out this study on the Wuhan, Alpha, Delta and Omicron strains allowing us to illustrate the evolution of the relationships we have highlighted according to these different viral strains. We addressed the following questions. 1) How can the mean infectious dose (one quantum, by definition in epidemiology) be measured and expressed as an amount of viral RNA molecules (in genome units, GU) or as a number of replicative viral particles (in plaque-forming units, PFU)? 2) How many infectious quanta are exhaled by an infected person per unit of time? 3) How many infectious quanta are exhaled, on average, integrated over the whole contagious period? 4) How do these quantities relate to the epidemic reproduction rate R as measured in epidemiology, and to the viral load, as measured by molecular biological methods? 5) How has the infectious dose evolved with the different strains of SARS-CoV-2? We make use of state-of-the-art modelling, reviewed and explained in the appendix of the article (Supplemental Information, SI), to answer these questions using data from the literature in both epidemiology and virology. We have considered the modification of these relationships according to the vaccination status of the population.

Quantifying the heterogeneous impact of lockdown policies on different socioeconomic classes during the first COVID-19 wave in Colombia

In the absence of vaccines, the most widespread reaction to curb the COVID-19 pandemic worldwide was the implementation of lockdowns or stay-at-home policies. Despite the reported usefulness of such policies, their efficiency was highly constrained by socioeconomic factors determining their feasibility and their associated outcome in terms of mobility reduction and the subsequent limitation of social activity. Here we investigate the impact of lockdown policies on the mobility patterns of different socioeconomic classes in the three major cities of Colombia during the first wave of the COVID-19 pandemic. In global terms, we find a consistent positive correlation between the reduction in mobility levels and the socioeconomic stratum of the population in the three cities, implying that those with lower incomes were less capable of adopting the aforementioned policies. Our analysis also suggests a strong restructuring of the mobility network of lowest socioeconomic strata during COVID-19 lockdown, increasing their endogenous mixing while hampering their connections with wealthiest areas due to a sharp reduction in long-distance trips.

Explicit modeling of antibody levels for infectious disease simulations in the context of SARS-CoV-2

Measurable levels of immunoglobulin G antibodies develop after infections with and vaccinations against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These antibody levels are dynamic: due to waning, antibody levels will drop over time. During the COVID-19 pandemic, multiple models predicting infection dynamics were used by policymakers to support the planning of public health policies. Explicitly integrating antibody and waning effects into the models is crucial for reliable calculations of individual infection risk. However, only few approaches have been suggested that explicitly treat these effects. This paper presents a methodology that explicitly models antibody levels and the resulting protection against infection for individuals within an agent-based model. The model was developed in response to the complexity of different immunization sequences and types and is based on neutralization titer studies. This approach allows complex population studies with explicit antibody and waning effects. We demonstrate the usefulness of our model in two use cases.

Community-based N95 distribution during the COVID-19 Omicron BA.1 surge: feasibility, 1-month utilization, and price implications

Masks and other non-pharmaceutical interventions can complement vaccines and treatments as a part of multilayered mitigation to reduce the burden of COVID-19 in high-risk settings like surges. Although N95s provide greater protection than cloth and procedure masks against airborne infectious illnesses, few people used N95s historically, potentially due to lack of familiarity and cost. The study was designed to examine the feasibility of distributing N95s during a COVID-19 surge. A follow-up survey summarized mask behavior. The investigators aimed to distribute 2,500 N95s to 500 adults in 5-packs with informational handouts at community locations during the COVID-19 Omicron BA.1 surge in New Orleans, Louisiana. A 1-month follow-up survey assessed utilization, safety perceptions, social diffusion of awareness of N95s, and purchase intentions. The investigators successfully distributed all 2,500 N95s during the peak of the BA.1 surge (December 13, 2021 to January 17, 2022). At 1-month follow-up, 96.7% of participants had tried an N95. They utilized an average of 3.42 (68.4%) of the five N95s, felt safer wearing N95s (Ps < 0.0001), discussed N95s with others (80.4%), and would wear N95s again if free (87.9%). Future utilization intentions were price sensitive. Communities will readily use public health tools like N95s when at risk and offered for free with useful information. Cost was identified as a key barrier to sustained utilization. Findings have immediate public policy implications for reducing national, regional, and organizational surges. The research provides an illustrative example of the importance of behavioral science in responding to public health crises.

Global face mask pollution: threats to the environment and wildlife, and potential solutions

Face masks are an indispensable low-cost public healthcare necessity for containing viral transmission. After the coronavirus disease (COVID-19) became a pandemic, there was an unprecedented demand for, and subsequent increase in face mask production and use, leading to global ecological challenges, including excessive resource consumption and significant environmental pollution. Here, we review the global demand volume for face masks and the associated energy consumption and pollution potential throughout their life cycle. First, the production and distribution processes consume petroleum-based raw materials and other energy sources and release greenhouse gases. Second, most methods of mask waste disposal result in secondary microplastic pollution and the release of toxic gases and organic substances. Third, face masks discarded in outdoor environments represent a new plastic pollutant and pose significant challenges to the environment and wildlife in various ecosystems. Therefore, the long-term impacts on environmental and wildlife health aspects related to the production, use, and disposal of face masks should be considered and urgently investigated. Here, we propose five reasonable countermeasures to alleviate these global-scale ecological crises induced by mask use during and following the COVID-19 pandemic era: increasing public awareness; improving mask waste management; innovating waste disposal methods; developing biodegradable masks; and formulating relevant policies and regulations. Implementation of these measures will help address the pollution caused by face masks.