Transmission routes of respiratory viruses among humans

Comparison of antimicrobial efficacy of different disinfectants on the biofilm formation in dental unit water systems using dip slide and conventional methods: A pilot study

OBJECTIVE

Biofilm formation in dental waterlines brings opportunistic infections, especially for immunosuppressive patients. This study aimed to determine biofilm-forming microorganisms by various methods and investigate disinfectants' effects on biofilm.

MATERIALS & METHODS

In the study, samples were obtained from the waterlines of 10-15 aged six dental units, before (0 min.) and after chlorine dioxide (ClO2) and hypochlorous acid (HOCl) treatment (1, 5, 10, 20, and 30 min.), and total colony counts were performed using conventional surface smear method (SSM) and dip slide method (DSM). The Congo red agar and Christensen methods were used to examine the biofilm-forming properties of the isolates. Monitoring of biofilm presence was also visualized by SEM scanning.

RESULTS

When DSM and SSM are compared in all units where ClO2 and HOCl are applied, DSM can detect bacterial growth even during periods of greater exposure to disinfectant application. Although DSM can achieve a value approaching 3% even at the 10th minute in units treated with HOCl; SSM does not show reproduction at the same disinfectant exposure and duration; It was observed that in the units where ClO2 was applied, the growth was no longer observed at the 10th minute with DSM, and SSM, 50% growth in the first minute of the units treated with ClO2 could not be detected in the 5th minute.

CONCLUSIONS

It is concluded that it can be advisable to routinely disinfect the dental unit water systems with non-toxic doses of ClO2 application before patient treatments in clinics and also to perform contamination controls at regular intervals with DSM, which is a sensitive and very practical method.

RESEARCH HIGHLIGHTS

It has been observed that the dip slide method can count bacteria more sensitively than conventional methods in dental water systems without the need for experienced personnel and equipment. The difference between biofilm formation in water systems before and after disinfectant exposure in SEM examinations is remarkable. The effects of ClO2 and HOCl on biofilm were investigated and bacterial growth was inhibited in dental units between 5 and 10 minutes with both disinfectants.

New Vaccines for Chronic Respiratory Patients

Chronic respiratory diseases (CRD) are responsible for more than four million deaths worldwide and have become especially prevalent in developed countries. Although the current therapies help manage daily symptoms and improve patients' quality of life, there is a major need to prevent exacerbations triggered mainly by respiratory infections. Therefore, CRD patients are a prime target for vaccination against infectious agents. In the present manuscript we review the state of the art of available vaccines specifically indicated in patients with CRDs. In addition to pneumococcus, influenza, pertussis, and SARS-CoV-2 vaccines, recently added immunization options like vaccines and monoclonal antibodies against respiratory syncytial virus, are particularly interesting in CRD patients. As new products reach the market, health authorities must be agile in updating immunization recommendations and in the programming of the vaccination of vulnerable populations such as patients with CRDs. Organizational and educational strategies might prove useful to increase vaccine uptake by CRD patients.

Impacts of human mobility on the citywide transmission dynamics of 18 respiratory viruses in pre- and post-COVID-19 pandemic years

Many studies have used mobile device location data to model SARS-CoV-2 dynamics, yet relationships between mobility behavior and endemic respiratory pathogens are less understood. We studied the effects of population mobility on the transmission of 17 endemic viruses and SARS-CoV-2 in Seattle over a 4-year period, 2018-2022. Before 2020, visits to schools and daycares, within-city mixing, and visitor inflow preceded or coincided with seasonal outbreaks of endemic viruses. Pathogen circulation dropped substantially after the initiation of COVID-19 stay-at-home orders in March 2020. During this period, mobility was a positive, leading indicator of transmission of all endemic viruses and lagging and negatively correlated with SARS-CoV-2 activity. Mobility was briefly predictive of SARS-CoV-2 transmission when restrictions relaxed but associations weakened in subsequent waves. The rebound of endemic viruses was heterogeneously timed but exhibited stronger, longer-lasting relationships with mobility than SARS-CoV-2. Overall, mobility is most predictive of respiratory virus transmission during periods of dramatic behavioral change and at the beginning of epidemic waves.

Droplet Digital RT-PCR (dd RT-PCR) Detection of SARS-CoV-2 in Honey Bees and Honey Collected in Apiaries across the Campania Region

Coronaviruses (CoVs), a subfamily of Orthocoronavirinae, are viruses that sometimes present a zoonotic character. Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is responsible for the recent outbreak of COVID-19, which, since its outbreak in 2019, has caused about 774,593,066 confirmed cases and 7,028,881 deaths. Aereosols are the main route of transmission among people; however, viral droplets can contaminate surfaces and fomites as well as particulate matter (PM) in suspensions of natural and human origin. Honey bees are well known bioindicators of the presence of pollutants and PMs in the environment as they can collect a great variety of substances during their foraging activities. The aim of this study was to evaluate the possible role of honey bees as bioindicators of the prevalence SARS-CoV-2. In this regard, 91 samples of honey bees and 6 of honey were collected from different apiaries of Campania region (Southern Italy) in four time periods from September 2020 to June 2022 and were analyzed with Droplet Digital RT-PCR for SARS-CoV-2 target genes Orf1b and N. The screening revealed the presence of SARS-CoV-2 in 12/91 in honey bee samples and in 2/6 honey samples. These results suggest that honey bees could also be used as indicators of outbreaks of airborne pathogens such as SARS-CoV-2.

Viral infection transmission and indoor air quality: A systematic review

Respiratory disease transmission in indoor environments presents persistent challenges for health authorities, as exemplified by the recent COVID-19 pandemic. This underscores the urgent necessity to investigate the dynamics of viral infection transmission within indoor environments. This systematic review delves into the methodologies of respiratory infection transmission in indoor settings and explores how the quality of indoor air (IAQ) can be controlled to alleviate this risk while considering the imperative of sustainability. Among the 2722 articles reviewed, 178 were retained based on their focus on respiratory viral infection transmission and IAQ. Fifty eight articles delved into SARS-CoV-2 transmission, 21 papers evaluated IAQ in contexts of other pandemics, 53 papers assessed IAQ during the SARS-CoV-2 pandemic, and 46 papers examined control strategies to mitigate infectious transmission. Furthermore, of the 46 papers investigating control strategies, only nine considered energy consumption. These findings highlight clear gaps in current research, such as analyzing indoor air and surface samples for specific indoor environments, oversight of indoor and outdoor parameters (e.g., temperature, relative humidity (RH), and building orientation), neglect of occupancy schedules, and the absence of considerations for energy consumption while enhancing IAQ. This study distinctly identifies the indoor environmental conditions conducive to the thriving of each respiratory virus, offering IAQ trade-offs to mitigate the risk of dominant viruses at any given time. This study argues that future research should involve digital twins in conjunction with machine learning (ML) techniques. This approach aims to enhance IAQ by analyzing the transmission patterns of various respiratory viruses while considering energy consumption.

The epidemic forest reveals the spatial pattern of the spread of acute respiratory infections in Jakarta, Indonesia

Acute respiratory infection (ARI) is a communicable disease of the respiratory tract that implies impaired breathing. The infection can expand from one to the neighboring areas at a region-scale level through a human mobility network. Specific to this study, we leverage a record of ARI incidences in four periods of outbreaks for 42 regions in Jakarta to study its spatio-temporal spread using the concept of the epidemic forest. This framework generates a forest-like graph representing an explicit spread of disease that takes the onset time, spatio-temporal distance, and case prevalence into account. To support this framework, we use logistic curves to infer the onset time of the outbreak for each region. The result shows that regions with earlier onset dates tend to have a higher burden of cases, leading to the idea that the culprits of the disease spread are those with a high load of cases. To justify this, we generate the epidemic forest for the four periods of ARI outbreaks and identify the implied dominant trees (that with the most children cases). We find that the primary infected city of the dominant tree has a relatively higher burden of cases than other trees. In addition, we can investigate the timely ( R t ) and spatial reproduction number ( R c ) by directly evaluating them from the inferred graphs. We find that R t for dominant trees are significantly higher than non-dominant trees across all periods, with regions in western Jakarta tend to have higher values of R c . Lastly, we provide simulated-implied graphs by suppressing 50% load of cases of the primary infected city in the dominant tree that results in a reduced R c , suggesting a potential target of intervention to depress the overall ARI spread.

What did we learn about changing behaviour during the COVID-19 pandemic? A systematic review of interventions to change hand hygiene and mask use behaviour

BACKGROUND

behaviour change interventions were central in the COVID-19 response and are vital for strengthening pandemic preparedness and resilience. To be effective, interventions must target specific behavioural determinants, but determinants are complex and multifaceted and there is a gap in robust, theory driven evidence on which behavioural determinants are most effective at changing mask usage and hand hygiene behaviour.

PURPOSE

to map available evidence on the types of hand hygiene and mask usage behaviour change interventions conducted during the COVID-19 pandemic and assess their effectiveness, feasibility and acceptability.

METHODS

we conducted a systematic review, searching four peer-reviewed databases for terms related to COVID-19, targeted behaviours (hand hygiene and mask usage) and interventions. Eligible studies were those which focused on adults or children in naturalistic, non-experimental settings; reported on an intervention designed to change hand hygiene and or mask usage to reduce COVID-19 transmission; provided clear outcome measures, including through self-report, proxy indicators or observation. Studies were excluded if they were purely qualitative, opinion pieces or based on secondary data alone; focused on health workers; measured intended rather than enacted behaviour; were conducted in laboratory or health care-based settings; involved infants; were published before the 11th of March 2020 (when COVID-19 was declared a pandemic) and published in a language other than English. There were no geographical limits set. Descriptive summaries were produced and the quality of evidence and reporting was evaluated. Studies were divided into three sub-groups according to the behaviour targeted and behaviour change techniques (BCTs) were mapped. Effect estimates were summarised and the relationship between BCTs and effect was explored. Feasibility and acceptability was summarised where reported. Due to the heterogeneity of studies included, meta-analysis could not be conducted.

FINDINGS

sixteen citations met the criteria, with sub-studies (two citations including multiple studies) totalling nineteen eligible studies. The majority were randomised controlled trials which targeted hand hygiene only and were conducted in high income nations, with none conducted in crisis settings. Due to the constraints of the pandemic, many interventions were delivered online. The quality of studies was low, with the majority demonstrating a medium risk of bias (Likert scale: low, medium, high). Whilst acceptability and feasibility was good, both were rarely evaluated. 'Natural consequences' was the most commonly used BCT group. Fourteen of the studies elicited positive or potentially positive effects in at least one intervention arm and/or targeted behaviour. Effective interventions typically targeted multiple individual BCTs, including 'Instruction on how to perform a behaviour', 'Information about health consequences', and group 'Reward and threat', through repeated engagement over a sustained period of time.

CONCLUSION

there is a substantial knowledge gap, particularly in low resource and crisis settings, and available evidence is of low quality. We must address these gaps to enable evidence-based practice and strengthen pandemic preparedness and resilience. Future research should include another systematic review which includes grey literature and different languages, as well as more robust evaluations which use implementation research to explore the impact of multiple BCTs in low resource and crisis settings. Evaluations should include assessments of acceptability, practicability, affordability and equity.

Sensitivity Evaluation of Enveloped and Non-enveloped Viruses to Ethanol Using Machine Learning: A Systematic Review

Viral diseases are a severe public health issue worldwide. During the coronavirus pandemic, the use of alcohol-based sanitizers was recommended by WHO. Enveloped viruses are sensitive to ethanol, whereas non-enveloped viruses are considerably less sensitive. However, no quantitative analysis has been conducted to determine virus ethanol sensitivity and the important variables influencing the inactivation of viruses to ethanol. This study aimed to determine viruses' sensitivity to ethanol and the most important variables influencing the inactivation of viruses exposed to ethanol based on machine learning. We examined 37 peer-reviewed articles through a systematic search. Quantitative analysis was employed using a decision tree and random forest algorithms. Based on the decision tree, enveloped viruses required around ≥ 35% ethanol with an average contact time of at least 1 min, which reduced the average viral load by 4 log10. In non-enveloped viruses with and without organic matter, ≥ 77.50% and ≥ 65% ethanol with an extended contact time of ≥ 2 min were required for a 4 log10 viral reduction, respectively. Important variables were assessed using a random forest based on the percentage increases in mean square error (%IncMSE) and node purity (%IncNodePurity). Ethanol concentration was a more important variable with a higher %IncMSE and %IncNodePurity than contact time for the inactivation of enveloped and non-enveloped viruses with the available organic matter. Because specific guidelines for virus inactivation by ethanol are lacking, data analysis using machine learning is essential to gain insight from certain datasets. We provide new knowledge for determining guideline values related to the selection of ethanol concentration and contact time that effectively inactivate viruses.

Unmasking the potential of secretory IgA and its pivotal role in protection from respiratory viruses

Mucosal immunity has regained its spotlight amidst the ongoing Coronavirus disease 19 (COVID-19) pandemic, with numerous studies highlighting the crucial role of mucosal secretory IgA (SIgA) in protection against Severe acute respiratory syndrome coronavirus-2 or SARS-CoV-2 infections. The observed limitations in the efficacy of currently authorized COVID-19 vaccines in inducing effective mucosal immune responses remind us of the limitations of systemic vaccination in promoting protective mucosal immunity. This resurgence of interest has motivated the development of vaccine platforms capable of enhancing mucosal responses, specifically the SIgA response, and the development of IgA-based therapeutics. Recognizing viral respiratory infections as a global threat, we would like to comprehensively review the existing knowledge on mucosal immunity, with a particular emphasis on SIgA, in the context of SARS-CoV-2, influenza, and Respiratory Syncytial Virus (RSV) infections. This review aims to describe the structural and functional specificities of SIgA, along with its nuanced role in combating influenza, RSV, and SARS-CoV-2 infections. Subsequent sections further elaborate promising vaccine strategies, including mucosal vaccines against Influenza, RSV, and SARS-CoV-2 respiratory viruses, currently undergoing preclinical and clinical development. Additionally, we address the challenges associated with mucosal vaccine development, concluding with a discussion on IgA-based therapeutics as a promising platform for the treatment of viral respiratory infections. This comprehensive review not only synthesizes current insights into mucosal immunity but also identifies critical knowledge gaps, strengthening the way for further advancements in our current understanding and approaches to combat respiratory viral threats.

Hydroxypropyl-Beta Cyclodextrin Barrier Prevents Respiratory Viral Infections: A Preclinical Study

The emergence and mutation of pathogenic viruses have been occurring at an unprecedented rate in recent decades. The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has developed into a global public health crisis due to extensive viral transmission. In situ RNA mapping has revealed angiotensin-converting enzyme 2 (ACE2) expression to be highest in the nose and lower in the lung, pointing to nasal susceptibility as a predominant route for infection and the cause of subsequent pulmonary effects. By blocking viral attachment and entry at the nasal airway using a cyclodextrin-based formulation, a preventative therapy can be developed to reduce viral infection at the site of entry. Here, we assess the safety and antiviral efficacy of cyclodextrin-based formulations. From these studies, hydroxypropyl beta-cyclodextrin (HPBCD) and hydroxypropyl gamma-cyclodextrin (HPGCD) were then further evaluated for antiviral effects using SARS-CoV-2 pseudotypes. Efficacy findings were confirmed with SARS-CoV-2 Delta variant infection of Calu-3 cells and using a K18-hACE2 murine model. Intranasal pre-treatment with HPBCD-based formulations reduced viral load and inflammatory signaling in the lung. In vitro efficacy studies were further conducted using lentiviruses, murine hepatitis virus (MHV), and influenza A virus subtype H1N1. These findings suggest HPBCD may be used as an agnostic barrier against transmissible pathogens, including but not limited to SARS-CoV-2.

Establishment of a screening platform based on human coronavirus OC43 for the identification of microbial natural products with antiviral activity

IMPORTANCE

The COVID-19 pandemic has revealed the lack of effective treatments against betacoronaviruses and the urgent need for new broad-spectrum antivirals. Natural products are a valuable source of bioactive compounds with pharmaceutical potential that may lead to the discovery of new antiviral agents. Specifically, compared to conventional synthetic molecules, microbial natural extracts possess a unique and vast chemical diversity and are amenable to large-scale production. The implementation of a high-throughput screening platform using the betacoronavirus OC43 in a human cell line infection model has provided proof of concept of the approach and has allowed for the rapid and efficient evaluation of 1,280 microbial extracts. The identification of several active compounds validates the potential of the platform for the search for new compounds with antiviral capacity.

Development of Human Rhinovirus RNA Reference Material Using Digital PCR

The human rhinovirus (RV) is a positive-stranded RNA virus that causes respiratory tract diseases affecting both the upper and lower halves of the respiratory system. RV enhances its replication by concentrating RNA synthesis within a modified host membrane in an intracellular compartment. RV infections often occur alongside infections caused by other respiratory viruses, and the RV virus may remain asymptomatic for extended periods. Alongside qualitative detection, it is essential to accurately quantify RV RNA from clinical samples to explore the relationships between RV viral load, infections caused by the virus, and the resulting symptoms observed in patients. A reference material (RM) is required for quality evaluation, the performance evaluation of molecular diagnostic products, and evaluation of antiviral agents in the laboratory. The preparation process for the RM involves creating an RV RNA mixture by combining RV viral RNA with RNA storage solution and matrix. The resulting RV RNA mixture is scaled up to a volume of 25 mL, then dispensed at 100 µL per vial and stored at -80 °C. The process of measuring the stability and homogeneity of RV RMs was conducted by employing reverse transcription droplet digital polymerase chain reaction (RT-ddPCR). Digital PCR is useful for the analysis of standards and can help to improve measurement compatibility: it represents the equivalence of a series of outcomes for reference materials and samples being analyzed when a few measurement procedures are employed, enabling objective comparisons between quantitative findings obtained through various experiments. The number of copies value represents a measured result of approximately 1.6 × 105 copies/μL. The RM has about an 11% bottle-to-bottle homogeneity and shows stable results for 1 week at temperatures of 4 °C and -20 °C and for 12 months at a temperature of -80 °C. The developed RM can enhance the dependability of RV molecular tests by providing a precise reference value for the absolute copy number of a viral target gene. Additionally, it can serve as a reference for diverse studies.

Stability of Feline Coronavirus in aerosols and dried in organic matrices on surfaces at various environmental conditions

Enveloped respiratory viruses, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can be transmitted through aerosols and contact with contaminated surfaces. The stability of these viruses outside the host significantly impacts their transmission dynamics and the spread of diseases. In this study, we investigated the tenacity of Feline Coronavirus (FCoV) in aerosols and on surfaces under varying environmental conditions. We found that airborne FCoV showed different stability depending on relative humidity (RH), with higher stability observed at low and high RH. Medium RH conditions (50-60%) were associated with increased loss of infectivity. Furthermore, FCoV remained infectious in the airborne state over 7 h. On stainless-steel surfaces, FCoV remained infectious for several months, with stability influenced by organic material and temperature. The presence of yeast extract and a temperature of 4 °C resulted in the longest maintenance of infectivity, with a 5 log10 reduction of the initial concentration after 167 days. At 20 °C, this reduction was achieved after 19 days. These findings highlight the potential risk of aerosol and contact transmission of respiratory viruses, especially in enclosed environments, over extended periods. Studying surrogate viruses like FCoV provides important insights into the behavior of zoonotic viruses like SARS-CoV-2 in the environment.

On-site airborne pathogen detection for infection risk mitigation

Human-infecting pathogens that transmit through the air pose a significant threat to public health. As a prominent instance, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that caused the COVID-19 pandemic has affected the world in an unprecedented manner over the past few years. Despite the dissipating pandemic gloom, the lessons we have learned in dealing with pathogen-laden aerosols should be thoroughly reviewed because the airborne transmission risk may have been grossly underestimated. From a bioanalytical chemistry perspective, on-site airborne pathogen detection can be an effective non-pharmaceutic intervention (NPI) strategy, with on-site airborne pathogen detection and early-stage infection risk evaluation reducing the spread of disease and enabling life-saving decisions to be made. In light of this, we summarize the recent advances in highly efficient pathogen-laden aerosol sampling approaches, bioanalytical sensing technologies, and the prospects for airborne pathogen exposure measurement and evidence-based transmission interventions. We also discuss open challenges facing general bioaerosols detection, such as handling complex aerosol samples, improving sensitivity for airborne pathogen quantification, and establishing a risk assessment system with high spatiotemporal resolution for mitigating airborne transmission risks. This review provides a multidisciplinary outlook for future opportunities to improve the on-site airborne pathogen detection techniques, thereby enhancing the preparedness for more on-site bioaerosols measurement scenarios, such as monitoring high-risk pathogens on airplanes, weaponized pathogen aerosols, influenza variants at the workplace, and pollutant correlated with sick building syndromes.

Willow (Salix spp.) bark hot water extracts inhibit both enveloped and non-enveloped viruses: study on its anti-coronavirus and anti-enterovirus activities

Introduction

Recurring viral outbreaks have a significant negative impact on society. This creates a need to develop novel strategies to complement the existing antiviral approaches. There is a need for safe and sustainable antiviral solutions derived from nature.

Objective

This study aimed to investigate the antiviral potential of willow (Salix spp.) bark hot water extracts against coronaviruses and enteroviruses. Willow bark has long been recognized for its medicinal properties and has been used in traditional medicines. However, its potential as a broad-spectrum antiviral agent remains relatively unexplored.

Methods

Cytopathic effect inhibition assay and virucidal and qPCR-based assays were used to evaluate the antiviral potential of the bark extracts. The mechanism of action was investigated using time-of-addition assay, confocal microscopy, TEM, thermal, and binding assays. Extracts were fractionated and screened for their chemical composition using high-resolution LC-MS.

Results

The native Salix samples demonstrated their excellent antiviral potential against the non-enveloped enteroviruses even at room temperature and after 45 s. They were equally effective against the seasonal and pandemic coronaviruses. Confocal microscopy verified the loss of infection capacity by negligible staining of the newly synthesized capsid or spike proteins. Time-of-addition studies demonstrated that Salix bark extract had a direct effect on the virus particles but not through cellular targets. Negative stain TEM and thermal assay showed that antiviral action on enteroviruses was based on the added stability of the virions. In contrast, Salix bark extract caused visible changes in the coronavirus structure, which was demonstrated by the negative stain TEM. However, the binding to the cells was not affected, as verified by the qPCR study. Furthermore, coronavirus accumulated in the cellular endosomes and did not proceed after this stage, based on the confocal studies. None of the tested commercial reference samples, such as salicin, salicylic acid, picein, and triandrin, had any antiviral activity. Fractionation of the extract and subsequent MS analysis revealed that most of the separated fractions were very effective against enteroviruses and contained several different chemical groups such as hydroxycinnamic acid derivatives, flavonoids, and procyanidins.

Conclusion

Salix spp. bark extracts contain several virucidal agents that are likely to act synergistically and directly on the viruses.

Design and testing of a sew-free origami mask for improvised respiratory protection

Respiratory aerosols with diameters smaller than 100μm have been confirmed as important vectors for the spread of diseases such as SARS-CoV-2. While disposable and cloth masks afford some protection, they are typically inefficient at filtering these aerosols and require specialized fabrication devices to produce. We describe a fabrication technique that makes use of a folding procedure (origami) to transform any filtration material into a mask. These origami masks can be fabricated by non-experts at minimal cost and effort, provide adequate filtration efficiencies, and are easily scaled to different facial sizes. Using a mannequin fit test simulator, we demonstrate that these masks can provide filtration efficiencies of over 90% while simultaneously providing greater comfort as demonstrated by pressure drops of <20 Pa. We also quantify mask leakage by measuring the variations in filtration efficiency and pressure drop when masks are sealed to the mannequin face compared to when the mask is unsealed but positioned to achieve the best fit. While leakage generally trended with pressure drop, some of the best performing mask media achieved <10% reduction in filtration efficiency due to leakage. Because this mask can provide high filtration efficiencies at low pressure drop compared to commercial alternatives, it is likely to promote greater mask wearing tolerance and acceptance.

Lung cDC1 and cDC2 dendritic cells priming naive CD8+ T cells in situ prior to migration to draining lymph nodes

The current paradigm indicates that naive T cells are primed in secondary lymphoid organs. Here, we present evidence that intranasal administration of peptide antigens appended to nanofibers primes naive CD8+ T cells in the lung independently and prior to priming in the draining mediastinal lymph node (MLN). Notably, comparable accumulation and transcriptomic responses of CD8+ T cells in lung and MLN are observed in both Batf3KO and wild-type (WT) mice, indicating that, while cDC1 dendritic cells (DCs) are the major subset for cross-presentation, cDC2 DCs alone are capable of cross-priming CD8+ T cells both in the lung and draining MLN. Transcription analyses reveal distinct transcriptional responses in lung cDC1 and cDC2 to intranasal nanofiber immunization. However, both DC subsets acquire shared transcriptional responses upon migration into the lymph node, thus uncovering a stepwise activation process of cDC1 and cDC2 toward their ability to cross-prime effector and functional memory CD8+ T cell responses.

Comparison of respiratory pathogens in children with community-acquired pneumonia before and during the COVID-19 pandemic

BACKGROUND

Multifaceted non-pharmaceutical interventions during the COVID-19 pandemic have not only reduced the transmission of SARS-CoV2, but have had an effect on the prevalence of other pathogens. This retrospective study aimed to compare and analyze the changes of respiratory pathogens in hospitalized children with community-acquired pneumonia.

METHODS

From January 2019 to December 2020, children with community-acquired pneumonia were selected from the Department of Respiratory Medicine, Shanghai Children's Medical Center. On the first day of hospitalization, sputum, throat swabs, venous blood samples from them were collected for detection of pathogens.

RESULTS

A total of 2596 children with community-acquired pneumonia were enrolled, including 1871 patients in 2019 and 725 in 2020. The detection rate in 2020 was lower than in 2019, whether single or multiple pathogens. Compared with 2019, the detection rate of virus, especially parainfluenza virus, influenza virus and respiratory syncytial virus, all decreased in 2020. On the contrary, the prevalence of human rhinovirus was much higher than that in 2019. In addition, the positivity rate for bacteria did not change much over the two years, which seemed to be less affected by COVID-19. And Mycoplasma pneumoniae which broke out in 2019 has been in low prevalence since March 2020 even following the reopening of school.

CONCLUSIONS

Strict public health interventions for COVID-19 in China have effectively suppressed the spread of not only SARS-CoV2 but parainfluenza virus, influenza virus and Mycoplasma pneumonia as well. However, it had a much more limited effect on bacteria and rhinovirus. Therefore, more epidemiological surveillance of respiratory pathogens will help improve early preventive measures.

Airborne influenza virus shedding by patients in health care units: Removal mechanisms affecting virus transmission

In this study, we characterize the distribution of airborne viruses (influenza A/B) in hospital rooms of patients with confirmed infections. Concurrently, we monitored fine particulate matter (PM2.5 & PM10) and several physical parameters including the room air exchange rate, temperature, and relative humidity to identify corresponding correlations with virus transport and removal determinants. The results continue to raise concerns about indoor air quality (IAQ) in healthcare facilities and the potential exposure of patients, staff and visitors to aerosolized viruses as well as elevated indoor PM levels caused by outdoor sources and/or re-suspension of settled particles by indoor activities. The influenza A virus was detected in 42% of 33 monitored rooms, with viruses detectible up to 1.5 m away from the infected patient. Active coughing was a statistically significant variable that contributed to a higher positive rate of virus detection in the collected air samples. Viral load across patient rooms ranged between 222 and 5,760 copies/m3, with a mean of 820 copies/m3. Measured PM2.5 and PM10 levels exceeded IAQ daily exposure guidelines in most monitored rooms. Statistical and numerical analyses showed that dispersion was the dominant viral removal pathway followed by settling. Changes in the relative humidity and the room's temperature were had a significant impact on the viral load removal. In closure, we highlight the need for an integrated approach to control determinants of IAQ in patients' rooms.

Admissions for Bronchiolitis at Children's Hospitals Before and During the COVID-19 Pandemic

Importance

The COVID-19 pandemic has been associated with a transient decrease in bronchiolitis hospitalizations compared with prepandemic patterns, but current effects remain unknown.

Objective

To analyze changes in patterns of bronchiolitis admissions at US children's hospitals during the 2020-2023 bronchiolitis seasons compared with the 2010-2019 seasons.

Design, Setting, and Participants

This retrospective cross-sectional study used data from 41 US children's hospitals in the Pediatric Health Information System database. Bronchiolitis has winter-predominant seasonality, so hospitalizations were grouped according to bronchiolitis season (from July through June). This study included all patients aged younger than 2 years admitted with a diagnosis of bronchiolitis between July 1, 2010, and June 30, 2023. Bronchiolitis seasons from July through June between 2010-2011 and 2019-2020 were classified as the prepandemic era, and seasons between 2020-2021 and 2022-2023 were classified as the pandemic era. Data analysis was performed from July 1, 2010, through June 30, 2023.

Exposures

Admission date.

Main Outcomes and Measures

The primary outcome was number of hospitalizations for bronchiolitis by season and month. Monthly admission counts from the prepandemic era were transformed into time series and used to train seasonal ensemble forecasting models. Forecasts were compared to monthly admissions during the pandemic era.

Results

In this study, there were 400 801 bronchiolitis admissions among 349 609 patients between July 1, 2010, and June 30, 2023. The median patient age was 6 (IQR, 2-12) months; 58.7% were boys and 43.7% were White. Hospitalizations increased gradually during the prepandemic era (median, 29 309 [IQR, 26 196-34 157]), decreased 69.2% (n = 9030) in the 2020-2021 season, and increased 75.3% (n = 51 397) in the 2022-2023 season. Patients in the pandemic era were older than those in the prepandemic era (median, 7 [IQR, 3-14] vs 6 [2-12] months; P < .001). Intensive care unit (ICU) admissions increased from 32.2% (96 245 of 298 535) in the prepandemic era to 36.7% (37 516 of 102 266) in the pandemic era (P < .001). The seasonality of bronchiolitis admissions changed during the pandemic era. Admissions peaked in August 2021 (actual 5036 vs 943 [95% CI, 0-2491] forecasted) and November 2022 (actual 10 120 vs 5268 [95% CI, 3425-7419] forecasted). These findings were unchanged in sensitivity analyses excluding children with complex chronic conditions and excluding repeat admissions. In a sensitivity analysis including all viral lower respiratory tract infections in children aged younger than 5 years, there were 66 767 admissions in 2022-2023 vs 35 623 (31 301-41 002) in the prepandemic era, with the largest increase in children aged 24 to 59 months.

Conclusions and Relevance

The findings of this cross-sectional study suggest that bronchiolitis hospitalizations decreased transiently and then increased markedly during the COVID-19 pandemic era. Patients admitted during the pandemic era were older and were more likely to be admitted to an ICU. These findings suggest that bronchiolitis seasonality has not yet returned to prepandemic patterns, and US hospitals should prepare for the possibility of atypical timing again in 2023.

LSTM-based recurrent neural network provides effective short term flu forecasting

BACKGROUND

Influenza virus is responsible for a yearly epidemic in much of the world. To better predict short-term, seasonal variations in flu infection rates and possible mechanisms of yearly infection variation, we trained a Long Short-Term Memory (LSTM)-based deep neural network on historical Influenza-Like-Illness (ILI), climate, and population data.

METHODS

Data were collected from the Centers for Disease Control and Prevention (CDC), the National Center for Environmental Information (NCEI), and the United States Census Bureau. The model was initially built in Python using the Keras API and tuned manually. We explored the roles of temperature, precipitation, local wind speed, population size, vaccination rate, and vaccination efficacy. The model was validated using K-fold cross validation as well as forward chaining cross validation and compared to several standard algorithms. Finally, simulation data was generated in R and used for further exploration of the model.

RESULTS

We found that temperature is the strongest predictor of ILI rates, but also found that precipitation increased the predictive power of the network. Additionally, the proposed model achieved a +1 week prediction mean absolute error (MAE) of 0.1973. This is less than half of the MAE achieved by the next best performing algorithm. Additionally, the model accurately predicted simulation data. To test the role of temperature in the network, we phase-shifted temperature in time and found a predictable reduction in prediction accuracy.

CONCLUSIONS

The results of this study suggest that short term flu forecasting may be effectively accomplished using architectures traditionally reserved for time series analysis. The proposed LSTM-based model was able to outperform comparison models at the +1 week time point. Additionally, this model provided insight into the week-to-week effects of climatic and biotic factors and revealed potential patterns in data series. Specifically, we found that temperature is the strongest predictor of seasonal flu infection rates. This information may prove to be especially important for flu forecasting given the uncertain long-term impact of the SARS-CoV-2 pandemic on seasonal influenza.

Persistence of Coronavirus on Surface Materials and Its Control Measures Using Nonthermal Plasma and Other Agents

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been responsible for the initiation of the global pandemic since 2020. The virus spreads through contaminated air particles, fomite, and surface-contaminated porous (i.e., paper, wood, and masks) and non-porous (i.e., plastic, stainless steel, and glass) materials. The persistence of viruses on materials depends on porosity, adsorption, evaporation, isoelectric point, and environmental conditions, such as temperature, pH, and relative humidity. Disinfection techniques are crucial for preventing viral contamination on animated and inanimate surfaces. Currently, there are few effective methodologies for preventing SARS-CoV-2 and other coronaviruses without any side effects. Before infection can occur, measures must be taken to prevent the persistence of the coronavirus on the surfaces of both porous and non-porous inanimate materials. This review focuses on coronavirus persistence in surface materials (inanimate) and control measures. Viruses are inactivated through chemical and physical methods; the chemical methods particularly include alcohol, chlorine, and peroxide, whereas temperature, pH, humidity, ultraviolet irradiation (UV), gamma radiation, X-rays, ozone, and non-thermal, plasma-generated reactive oxygen and nitrogen species (RONS) are physical methods.

High resolution mass spectrometry of respiratory viruses: beyond MALDI-ToF instruments for next generation viral typing, subtyping, variant and sub-variant identification

In the wake of the SARS-CoV2 pandemic, a point has been reached to assess the limitations and strengths of the analytical responses to virus identification and characterisation. Mass spectrometry has played a growing role in this area for over two decades, and this review highlights the benefits of mass spectrometry (MS) over PCR-based methods together with advantages of high mass resolution, high mass accuracy strategies over conventional MALDI-ToF and ESI-MS/MS instrumentation. This review presents the development and application of high resolution mass spectrometry approaches to detect, characterise, type and subtype, and distinguish variants of the influenza and SARS-CoV-2 respiratory viruses. The detection limits for the identification of SARS-CoV2 virus variants in clinical specimens and the future uptake of high resolution instruments in clinical laboratories are discussed. The same high resolution mass data can be used to monitor viral evolution and follow evolutionary trajectories.

Air purifiers for reducing the incidence of acute respiratory infections in australian residential aged care facilities: A study protocol for a randomised control trial

INTRODUCTION

Adults living in Residential Aged Care Facilities (RACFs) are highly susceptible to seasonal respiratory infections. Evidence indicates that the aerosols contaminated with virus particles in closed indoor spaces may play a significant role in the transmission of respiratory infections. In this protocol paper, we outline details of a planned RCT which aims to evaluate the effectiveness of portable in room air purifiers in reducing the risk of ARIs among residents in Australian RACFs. This study uses a multi-centre double-blind randomised crossover design. Three RACFs in a regional area of New South Wales will be invited to participate in the study. Air purifiers with or without high-efficiency particulate absorbing (HEPA) filters will be placed in the rooms of residents who are enrolled in the trial. The primary outcome will be a reduction in the incidence of ARI and the secondary outcomes will be the time to first infection, number of emergency department admissions, hospital admissions, and medical consultations due to an ARI.

CONCLUSION

To our knowledge, this will be the first RCT using air purifiers in resident rooms to identify their effect in reducing ARIs in RACFs. If our findings indicate some potential benefit for in-room air purification, it will help provide support and justification for larger trials, which may include a facility wide approach to air purification.

Estimation of the relationship between meteorological factors and measles using spatiotemporal Bayesian model in Shandong Province, China

BACKGROUND

Measles-containing vaccine (MCV) has been effective in controlling the spread of measles. Some countries have declared measles elimination. But recently years, the number of cases worldwide has increased, posing a challenge to the global goal of measles eradication. This study estimated the relationship between meteorological factors and measles using spatiotemporal Bayesian model, aiming to provide scientific evidence for public health policy to eliminate measles.

METHODS

Descriptive statistical analysis was performed on monthly data of measles and meteorological variables in 136 counties of Shandong Province from 2009 to 2017. Spatiotemporal Bayesian model was used to estimate the effects of meteorological factors on measles, and to evaluate measles risk areas at county level. Case population was divided into multiple subgroups according to gender, age and occupation. The effects of meteorological factors on measles in subgroups were compared.

RESULTS

Specific meteorological conditions increased the risk of measles, including lower relative humidity, temperature, and atmospheric pressure; higher wind velocity, sunshine duration, and diurnal temperature variation. Taking lowest value (Q1) as reference, RR (95%CI) for higher temperatures (Q2-Q4) were 0.79 (0.69-0.91), 0.54 (0.44-0.65), and 0.48 (0.38-0.61), respectively; RR (95%CI) for higher relative humidity (Q2-Q4) were 0.76 (0.66-0.88), 0.56 (0.47-0.67), and 0.49 (0.38-0.63), respectively; RR (95%CI) for higher wind velocity (Q2-Q4) were 1.43 (1.25-1.64), 1.85 (1.57-2.18), 2.00 (1.59-2.52), respectively. 22 medium-to-high risk counties were identified, mainly in northwestern, southwestern and central Shandong Province. The trend was basically same in the effects of meteorological factors on measles in subgroups, but the magnitude of the effects was different.

CONCLUSIONS

Meteorological factors have an important impact on measles. It is crucial to integrate these factors into public health policies for measles prevention and control in China.

Common cold

The common cold is a unique human disease, as it is arguably the most common disease and because of the large number of respiratory viruses causing colds it is one of the most complex of human diseases. This review discusses the respiratory viruses and notes that all these viruses may cause the illness complex recognised as the common cold. The common cold is discussed as part of the "iceberg concept" of disease which ranges from asymptomatic infection to severe illness and death. The factors influencing the incidence of colds are discussed: crowding and sociability, stress, smoking and alcohol, immune status, sex, age, sleep, season, chilling, nutrition and exercise. The mechanism of symptoms related to the innate immune response is explained and symptomatic treatments are tabulated. Morbidity associated with common cold is discussed and possible vaccines.

Hemagglutinin stability as a key determinant of influenza A virus transmission via air

To cause pandemics, zoonotic respiratory viruses need to adapt to replication in and spread between humans, either via (indirect or direct) contact or through the air via droplets and aerosols. To render influenza A viruses transmissible via air, three phenotypic viral properties must change, of which receptor-binding specificity and polymerase activity have been well studied. However, the third adaptive property, hemagglutinin (HA) acid stability, is less understood. Recent studies show that there may be a correlation between HA acid stability and virus survival in the air, suggesting that a premature conformational change of HA, triggered by low pH in the airways or droplets, may render viruses noninfectious before they can reach a new host. We here summarize available data from (animal) studies on the impact of HA acid stability on airborne transmission and hypothesize that the transmissibility of other respiratory viruses may also be impacted by an acidic environment in the airways.

Decay rate estimation of respiratory viruses in aerosols and on surfaces under different environmental conditions

Majority of the viral outbreaks are super-spreading events established within 2-10 h, dependent on a critical time interval for successful transmission between humans, which is governed by the decay rates of viruses. To evaluate the decay rates of respiratory viruses over a short span, we calculated their decay rate values for various surfaces and aerosols. We applied Bayesian regression and ridge regression and determined the best estimation for respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), influenza viruses, and respiratory syncytial virus (RSV); the decay rate values in aerosols for these viruses were 4.83 ± 5.70, 0.40 ± 0.24, 0.11 ± 0.04, 2.43 ± 5.94, and 1.00 ± 0.50 h^-1, respectively. The highest decay rate values for each virus type differed according to the surface type. According to the model performance criteria, the Bayesian regression model was better for SARS-CoV-2 and influenza viruses, whereas ridge regression was better for SARS-CoV and MERS-CoV. A simulation using a better estimation will help us find effective non-pharmaceutical interventions to control virus transmissions.

Quantitatively Visualizing Airborne Disease Transmission Risks of Different Exhalation Activities through CO2 Imaging

Aerosol transmission has played a leading role in COVID-19 pandemic. However, there is still a poor understanding about how it is transmitted. This work was designed to study the exhaled breath flow dynamics and transmission risks under different exhaling modes. Using an infrared photography device, exhaled flow characteristics of different breathing activities, such as deep breathing, dry coughing, and laughing, together with the roles of mouth and nose were characterized by imaging CO2 flow morphologies. Both mouth and nose played an important role in the disease transmission though in the downward direction for the nose. In contrast to the trajectory commonly modeled, the exhaled airflows appeared with turbulent entrainments and obvious irregular movements, particularly the exhalations involving mouth were directed horizontal and had a higher propagation capacity and transmission risk. While the cumulative risk was high for deep breathing, those transient ones from dry coughing, yawning, and laughing were also shown to be significant. Various protective measures including masks, canteen table shields, and wearable devices were visually demonstrated to be effective for altering the exhaled flow directions. This work is useful to understanding the risk of aerosol infection and guiding the formulation of its prevention and control strategies. Experimental data also provide important information for refining model boundary conditions.

Resurgence of Respiratory Syncytial Virus in Children: An Out-of-Season Epidemic in Portugal

INTRODUCTION

An out-of-season increase in respiratory syncytial virus (RSV) incidence was observed in Portugal from June 2021 onwards, revealing a continuing surge in cases throughout 2021/2022 autumn/winter. We aimed to describe this out-of-season epidemic and define its epidemic period, by analysing RSV incidence from week 40 of 2020 (2020-W40) to week 18 of 2022 (2022-W18).

MATERIAL AND METHODS

Surveillance data on weekly RSV laboratory confirmed cases, in Portugal, was used to monitor RSV incidence using CUSUM test methodology for count data.

RESULTS

In 2021-W23, the CUSUM score identified a significant increase in the risk of RSV. By that time, the percentage of RSV positive tests rose from 1% in 2021-W22 (3/265) to 6% in 2021-W23 (18/298). Despite a sharp decrease in RSV incidence on 2021-W33 and on 2022-W02, the CUSUM score stayed over the limit up to 2022-W07, indicating that the RSV activity remained at an epidemic level. Distinct peaks of RSV cases were observed between 2021-W30 and 2021-W32 (average of 77 RSV cases per week) and between 2021-W39 and 2021-W41 (average of 79 RSV cases per week) with positivity rates around 60%.

CONCLUSION

An out-of-season RSV epidemic was identified, with a longer epidemic period compared with previous seasons. Possible reasons include relaxation of COVID-19 physical distancing measures and a greater proportion of population susceptible to disease. As several factors may change the pattern of RSV activity, countries should implement year-round surveillance RSV surveillance systems. These findings might have an impact on public health planning regarding future RSV surges, namely, on the palivizumab prophylaxis period for high-risk infants.

Atomic layer deposition of ZnO on polypropylene nonwovens for photocatalytic antibacterial facemasks

Addressing respiratory infectious diseases remains one of the main priorities due to the increased risk of exposure caused by population growth, increasing international travel and commerce, and most recently, the COVID-19 outbreak. In the war against respiratory diseases, facemasks are powerful tools to obstruct the penetration of microorganisms, thereby protecting the wearer from infections. Nonetheless, the intercepted microorganisms on the surface of facemasks may proliferate and lead to secondary infection. To solve this problem, atomic layer deposition is introduced to deposit uniform and mechanically robust ZnO layers on polypropylene (PP) nonwoven fabrics, a widely used raw material in fabricating facemasks. The loading of ZnO demonstrates no adverse effects on the separation performance of facemasks, and the filtration efficiency of the facemasks towards different types of nanoparticles remains higher than 98.9%. Moreover, the modified PP nonwoven fabrics are granted with excellent antibacterial activity and photocatalytic sterilization ability, which can inactivate both germ-negative and germ-positive bacteria (E. coliandS. aureus) effectively with and without light illumination. Therefore, the modified PP nonwoven fabrics are potential candidates to be used as the outer layer on facemasks and endow them with photocatalytic antibacterial activity.

Evolution of SARS-CoV-2 Variants: Implications on Immune Escape, Vaccination, Therapeutic and Diagnostic Strategies

The COVID-19 pandemic caused by SARS-CoV-2 is associated with a lower fatality rate than its SARS and MERS counterparts. However, the rapid evolution of SARS-CoV-2 has given rise to multiple variants with varying pathogenicity and transmissibility, such as the Delta and Omicron variants. Individuals with advanced age or underlying comorbidities, including hypertension, diabetes and cardiovascular diseases, are at a higher risk of increased disease severity. Hence, this has resulted in an urgent need for the development of better therapeutic and preventive approaches. This review describes the origin and evolution of human coronaviruses, particularly SARS-CoV-2 and its variants as well as sub-variants. Risk factors that contribute to disease severity and the implications of co-infections are also considered. In addition, various antiviral strategies against COVID-19, including novel and repurposed antiviral drugs targeting viral and host proteins, as well as immunotherapeutic strategies, are discussed. We critically evaluate strategies of current and emerging vaccines against SARS-CoV-2 and their efficacy, including immune evasion by new variants and sub-variants. The impact of SARS-CoV-2 evolution on COVID-19 diagnostic testing is also examined. Collectively, global research and public health authorities, along with all sectors of society, need to better prepare against upcoming variants and future coronavirus outbreaks.

A review on indoor airborne transmission of COVID-19– modelling and mitigation approaches

In the past few years, significant efforts have been made to investigate the transmission of COVID-19. This paper provides a review of the COVID-19 airborne transmission modeling and mitigation strategies. The simulation models here are classified into airborne transmission infectious risk models and numerical approaches for spatiotemporal airborne transmissions. Mathematical descriptions and assumptions on which these models have been based are discussed. Input data used in previous simulation studies to assess the dispersion of COVID-19 are extracted and reported. Moreover, measurements performed to study the COVID-19 airborne transmission within indoor environments are introduced to support validations for anticipated future modeling studies. Transmission mitigation strategies recommended in recent studies have been classified to include modifying occupancy and ventilation operations, using filters and air purifiers, installing ultraviolet (UV) air disinfection systems, and personal protection compliance, such as wearing masks and social distancing. The application of mitigation strategies to various building types, such as educational, office, public, residential, and hospital, is reviewed. Recommendations for future works are also discussed based on the current apparent knowledge gaps covering both modeling and mitigation approaches. Our findings show that different transmission mitigation measures were recommended for various indoor environments; however, there is no conclusive work reporting their combined effects on the level of mitigation that may be achieved. Moreover, further studies should be conducted to understand better the balance between approaches to mitigating the viral transmissions in buildings and building energy consumption.

Characterization of SARS-CoV-2 Distribution and Microbial Succession in a Clinical Microbiology Testing Facility during the SARS-CoV-2 Pandemic

The exchange of microbes between humans and the built environment is a dynamic process that has significant impact on health. Most studies exploring the microbiome of the built environment have been predicated on improving our understanding of pathogen emergence, persistence, and transmission. Previous studies have demonstrated that SARS-CoV-2 presence significantly correlates with the proportional abundance of specific bacteria on surfaces in the built environment. However, in these studies, SARS-CoV-2 originated from infected patients. Here, we perform a similar assessment for a clinical microbiology lab while staff were handling SARS-CoV-2 infected samples. The goal of this study was to understand the distribution and dynamics of microbial population on various surfaces within different sections of a clinical microbiology lab during a short period of 2020 Coronavirus disease (COVID-19) pandemic. We sampled floors, benches, and sinks in 3 sections (bacteriology, molecular microbiology, and COVID) of an active clinical microbiology lab over a 3-month period. Although floor samples harbored SARS-CoV-2, it was rarely identified on other surfaces, and bacterial diversity was significantly greater on floors than sinks and benches. The floors were primarily colonized by bacteria common to natural environments (e.g., soils), and benchtops harbored a greater proportion of human-associated microbes, including Staphylococcus and Streptococcus. Finally, we show that the microbial composition of these surfaces did not change over time and remained stable. Despite finding viruses on the floors, no lab-acquired infections were reported during the study period, which suggests that lab safety protocols and sanitation practices were sufficient to prevent pathogen exposures. IMPORTANCE For decades, diagnostic clinical laboratories have been an integral part of the health care systems that perform diagnostic tests on patient's specimens in bulk on a regular basis. Understanding their microbiota should assist in designing and implementing disinfection, and cleaning regime in more effective way. To our knowledge, there is a lack of information on the composition and dynamics of microbiota in the clinical laboratory environments, and, through this study, we have tried to fill that gap. This study has wider implications as understanding the makeup of microbes on various surfaces within clinical laboratories could help identify any pathogenic bacterial taxa that could have colonized these surfaces, and might act as a potential source of laboratory-acquired infections. Mapping the microbial community within these built environments may also be critical in assessing the reliability of laboratory safety and sanitation practices to lower any potential risk of exposures to health care workers.

Computational optimization of delivery parameters to guide the development of targeted Nasal spray

Airborne transmission by droplets and aerosols is known to play a critical role in the spread of many viruses amongst which are the common flu and the more recent SARS-CoV-2 viruses. In the case of SARS-CoV-2, the nasal cavity not only constitutes an important viral entry point, but also a primary site of infection (Sungnak W. et al. Nat. Med. 26:681-687. https://doi.org/10.1038/s41591-020-0868-6 , 2020).. Although face masks are a well-established preventive measure, development of novel and easy-to-use prophylactic measures would be highly beneficial in fighting viral spread and the subsequent emergence of variants of concern (Tao K. et al. Nat Rev Genet 22:757-773. https://doi.org/10.1038/s41576-021-00408-x , 2021). Our group has been working on optimizing a nasal spray delivery system that deposits particles inside the susceptible regions of the nasal cavity to act as a mechanical barrier to impede viral entry. Here, we identify computationally the delivery parameters that maximize the protection offered by this barrier. We introduce the computational approach and quantify the protection rate obtained as a function of a broad range of delivery parameters. We also introduce a modified design and demonstrate that it significantly improves deposition, thus constituting a viable approach to protect against nasal infection of airborne viruses. We then discuss our findings and the implications of this novel system on the prevention of respiratory diseases and targeted drug delivery.

Protocol of a randomised controlled trial to assess medical staff's inhalation exposure to infectious particles exhaled by patients during oesophagogastroduodenoscopy and the efficacy of surgical masks in this context

BACKGROUND

Aerosol-generating procedures such as oesophagogastroduodenoscopy (OGD) result in infectious particles being exhaled by patients. This substantially increases the medical staff's risk of occupational exposure to pathogenic particles via airway inhalation and facial mucosal deposition. Infectious particles are regarded as a key route of transmission of SARS-CoV-2 and, thus, represents a major risk factor for medical staff during the ongoing COVID-19 pandemic. There is a need for quantitative evidence on medical staff's risk of multiroute exposure to infectious particles exhaled by patients during OGD to enable the development of practical, feasible and economical methods of risk-reduction for use in OGD and related procedures. This randomised controlled trial (RCT)-Personal protective EquiPment intervention TrIal for oesophagogastroDuodEnoscopy (PEPTIDE)-aims to establish a state-of-the-art protocol for quantifying the multiroute exposure of medical staff to infectious particles exhaled by patients during real OGD procedures.

METHOD AND ANALYSIS

PEPTIDE will be a prospective, two-arm, RCT using quantitative methods and will be conducted at a tertiary hospital in China. It will enrol 130 participants (65 per group) aged over 18. The intervention will be an anthropomorphic model with realistic respiratory-related morphology and respiratory function that simulates a medical staff member. This model will be used either without or with a surgical mask, depending on the group allocation of a participant, and will be placed beside the participants as they undergo an OGD procedure. The primary outcome will be the anthropomorphic model's airway dosage of the participants' exhaled infectious particles with or without a surgical mask, and the secondary outcome will be the anthropomorphic model's non-surgical mask-covered facial mucosa dosage of the participants' exhaled infectious particles. Analyses will be performed in accordance with the type of data collected (categorical or quantitative data) using SPSS (V.26.0) and RStudio (V.1.3.959).

ETHICS AND DISSEMINATION

Ethical approval for this RCT was obtained from the Ethics Committee of Peking Union Medical College Hospital (ZS-3377). All of the potential participants who agree to participate will provide their written informed consent before they are enrolled. The results will be disseminated through presentations at national and international conferences and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05321056.

Spatial and temporal distribution of emerging airborne viral infectious diseases outbreaks on a global scale

Aim

This study aimed to explore the spatial and temporal characteristics of emerging airborne viral infectious diseases outbreaks worldwide.

Subject and methods

We conducted a systematic literature review on outbreaks of emerging airborne viral infectious diseases and calculated outbreak number and intensity at the country level. Fisher's exact test was used to compare the viral infectious diseases outbreaks in different income-level regions. To identify the major airborne viral infectious diseases outbreaks, we ranked and extracted the leading viral infectious diseases in outbreak number and intensity in each country by year.

Results

A total of 2505 outbreaks were reported from 1873 to 2021 across 2010 studies. There were 47 countries (47/130, 36.15%) with more frequent emerging airborne viral infectious disease outbreaks (more than nine outbreaks), and these countries mainly distributed in high-income regions (22/47 countries, 46.81%, p < 0.05), especially in Western Europe (14/47 countries, 29.79%, p < 0.05). The number of overall outbreaks was more in the United States and China than in other countries in different years. Outbreaks of measles and influenza are always frequent and intense. Highly pathogenic human coronaviruses infection caused short-term pandemics during which their outbreak number and intensity exceeded other viruses. Rift valley fever outbreaks in the human population are spreading outside of Africa through the flow of goods and travelers.

Conclusion

Countries in high-income regions reported more emerging airborne viral infectious diseases outbreaks, especially in the Western European region, the United States, and China. It is urgent to strengthen collaborative surveillance of emerging airborne viruses, cross-border flow of goods and travelers, and ecological environment to avoid the spread of viral infectious diseases outbreaks worldwide.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-023-01850-3.

Evaluation of Environmental Stability and Disinfectant Effectiveness for Human Coronavirus OC43 on Human Skin Surface

The environmental stability of human coronavirus OC43 (HCoV-OC43) on the surface of human skin and the effectiveness of disinfectant against HCoV-OC43, which are important to prevent contact transmission, have not been clarified in previous studies. Using previously generated models, we evaluated HCoV-OC43 stability and disinfection effectiveness. Then we compared the results with those for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The median survival time of HCoV-OC43 on the surface of human skin was 24.6 h (95% confidence interval, 19.7 to 29.6 h), which was higher than that of SARS-CoV-2 (10.8 h). Although the in vitro disinfectant effectiveness evaluation showed that HCoV-OC43 has a higher ethanol resistance than SARS-CoV-2, HCoV-OC43 on the skin surface was completely inactivated by a minimum of 50% ethanol within 5 s (the log reduction values were >4.0). Moreover, 1.0% chlorhexidine gluconate and 0.2% benzalkonium chloride showed relatively high disinfectant effectiveness, and the log reduction values when these disinfectants were applied for 15 s were >3.0. HCoV-OC43 is highly stable on the skin surface, which may increase the risk of contact transmission. Although HCoV-OC43 has relatively high ethanol resistance, appropriate hand hygiene practices with current alcohol-based disinfectants sufficiently reduce the risk of contact transmission. IMPORTANCE This study revealed the environmental stability of HCoV-OC43 and disinfectant effectiveness against HCoV-OC43, which had not been demonstrated in previous studies. HCoV-OC43 is highly stable on the surface of human skin, with a survival time of approximately 25 h. High stability of HCoV-OC43 may increase the risk of contact transmission. Furthermore, the in vitro disinfectant effectiveness evaluation showed that HCoV-OC43, which is classified as an envelope virus, has a relatively high ethanol resistance. This finding suggests that disinfectant effectiveness may vary greatly depending on the virus and that each virus targeted for infection control should be evaluated individually. HCoV-OC43 on the skin surface was rapidly inactivated by 50% ethanol, which suggests that appropriate hand hygiene practices with current alcohol-based disinfectants can sufficiently reduce the risk of HCoV-OC43 contact transmission.

Comparing the Etiology of Viral Acute Respiratory Illnesses Between Children Who Do and Do Not Attend Childcare

BACKGROUND AND OBJECTIVE

Childcare attendance is a common risk factor for acute respiratory illness (ARI) in young children. Our goal was to better understand the specific respiratory viruses that predominate in childcare, which may support the development of tailored illness prevention and intervention strategies in childcare settings.

METHODS

Using data from a prospective household cohort of ARI surveillance, we assessed specimen from 1418 ARIs reported by 359 childcare-aged children over 6 study seasons (2012/2013 through 2017/2018). Respiratory swabs were tested by polymerase chain reaction for 9 respiratory viruses. A mixed-effect logistic regression model was used to compare odds of various viral detection outcomes. The Shannon's Diversity index was used to compare the richness (ie, number of species) and diversity (ie, relative species abundance) associated with respiratory viruses detected in both groups.

RESULTS

At least 1 virus was detected in 75.5% of childcare-associated ARIs and in 80.1% of homecare ARIs. Compared with illnesses among homecare children, childcare illnesses were associated with significantly higher odds of detected adenovirus (odds ratio = 1.86, 95% confidence interval = 1.05-3.28) and human metapneumovirus (odds ratio = 1.76, 95% confidence interval = 1.03-3.0). The pool of viruses associated with childcare ARI was found to be significantly richer and more diverse than that of viruses associated with homecare ARI (P < 0.0001).

CONCLUSIONS

Children attending childcare experience a higher risk of adenovirus and human metapneumovirus infection and are regularly exposed to a rich and diverse pool of respiratory viruses in childcare environments. Our results underscore the necessity of thorough and multifaceted viral prevention strategies in childcare settings.

Quinones as Promising Compounds against Respiratory Viruses: A Review

Respiratory viruses represent a world public health problem, giving rise to annual seasonal epidemics and several pandemics caused by some of these viruses, including the COVID-19 pandemic caused by the novel SARS-CoV-2, which continues to date. Some antiviral drugs have been licensed for the treatment of influenza, but they cause side effects and lead to resistant viral strains. Likewise, aerosolized ribavirin is the only drug approved for the therapy of infections by the respiratory syncytial virus, but it possesses various limitations. On the other hand, no specific drugs are licensed to treat other viral respiratory diseases. In this sense, natural products and their derivatives have appeared as promising alternatives in searching for new compounds with antiviral activity. Besides their chemical properties, quinones have demonstrated interesting biological activities, including activity against respiratory viruses. This review summarizes the activity against respiratory viruses and their molecular targets by the different types of quinones (both natural and synthetic). Thus, the present work offers a general overview of the importance of quinones as an option for the future pharmacological treatment of viral respiratory infections, subject to additional studies that support their effectiveness and safety.

Occurrence and transport of SARS-CoV-2 in wastewater streams and its detection and remediation by chemical-biological methods

This paper explains the transmission of SARS-CoV and influences of several environmental factors in the transmission process. The article highlighted several methods of collection, sampling and monitoring/estimation as well as surveillance tool for detecting SARS-CoV in wastewater streams. In this context, WBE (Wastewater based epidemiology) is found to be the most effective surveillance tool. Several methods of genomic sequencing are discussed in the paper, which are applied in WBE, like qPCR-based wastewater testing, metagenomics-based analysis, next generation sequencing etc. Additionally, several types of biosensors (colorimetric biosensor, mobile phone-based biosensors, and nanomaterials-based biosensors) showed promising results in sensing SARS-CoV in wastewater. Further, this review paper outlined the gaps in assessing the factors responsible for transmission and challenges in detection and monitoring along with the remediation and disinfection methods of this virus in wastewater. Various methods of disinfection of SARS-CoV-2 in wastewater are discussed (primary, secondary, and tertiary phases) and it is found that a suite of disinfection methods can be used for complete disinfection/removal of the virus. Application of ultraviolet light, ozone and chlorine-based disinfectants are also discussed in the context of treatment methods. This study calls for continuous efforts to gather more information about the virus through continuous monitoring and analyses and to address the existing gaps and identification of the most effective tool/ strategy to prevent SARS-CoV-2 transmission. Wastewater surveillance can be very useful in effective surveillance of future pandemics and epidemics caused by viruses, especially after development of new technologies in detecting and disinfecting viral pathogens more effectively.

Microscopic model on indoor propagation of respiratory droplets

Indoor propagation of airborne diseases is yet poorly understood. Here, we theoretically study a microscopic model based on the motions of virus particles in a respiratory microdroplet, responsible for airborne transmission of diseases, to understand their indoor propagation. The virus particles are driven by a driving force that mimics force due to gushing of air by devices like indoor air conditioning along with the gravity. A viral particle within the droplet experiences viscous drag due to the droplet medium, force due to interfacial tension at the droplet boundary, the thermal forces and mutual interaction forces with the other viral particles. We use Brownian Dynamics (BD) simulations and scaling arguments to study the motion of the droplet, given by that of the center of mass of the viral assembly. The BD simulations show that in presence of the gravity force alone, the time the droplet takes to reach the ground level, defined by the gravitational potential energy being zero, from a vertical height H,t_f∼γ^-0.1 dependence, where γ is the interfacial tension. In presence of the driving force of magnitude F₀ and duration τ₀, the horizontal propagation length, Y_max from the source increase linearly with τ₀, where the slope is steeper for larger F₀. Our scaling analysis explains qualitatively well the simulation observations and show long-distance transmission of airborne respiratory droplets in the indoor conditions due to F₀ ∼ nano-dyne.

Smart Mask as Wearable for Post-Pandemic Personal Healthcare

A mask serves as a simple external barrier that protects humans from infectious particles from poor air conditions in the surrounding environment. As an important personal protective equipment (PPE) to protect our respiratory system, masks are able not only to filter pathogens and dust particles but also to sense, reflect or even respond to environmental conditions. This smartness is of particular interest among academia and industries due to its potential in disease detection, health monitoring and caring aspects. In this review, we provide an overlook of the current air filtration strategies used in masks, from structural designs to integrated functional modules that empower the mask's ability to sense and transfer physiological or environmental information to become smart. Specifically, we discussed recent developments in masks designed to detect macroscopic physiological signals from the wearer and mask-based disease diagnoses, such as COVID-19. Further, we propose the concept of next-generation smart masks and the requirements from material selection and function design perspectives that enable masks to interact and play crucial roles in health-caring wearables.

Physical interventions to interrupt or reduce the spread of respiratory viruses

BACKGROUND

Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review last published in 2020. We include results from studies from the current COVID-19 pandemic.

OBJECTIVES

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, CINAHL, and two trials registers in October 2022, with backwards and forwards citation analysis on the new studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, glasses, and gargling) to prevent respiratory virus transmission.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 11 new RCTs and cluster-RCTs (610,872 participants) in this update, bringing the total number of RCTs to 78. Six of the new trials were conducted during the COVID-19 pandemic; two from Mexico, and one each from Denmark, Bangladesh, England, and Norway. We identified four ongoing studies, of which one is completed, but unreported, evaluating masks concurrent with the COVID-19 pandemic. Many studies were conducted during non-epidemic influenza periods. Several were conducted during the 2009 H1N1 influenza pandemic, and others in epidemic influenza seasons up to 2016. Therefore, many studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID-19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high-income countries; crowded inner city settings in low-income countries; and an immigrant neighbourhood in a high-income country. Adherence with interventions was low in many studies. The risk of bias for the RCTs and cluster-RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included 12 trials (10 cluster-RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and 10 in the community). Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants; moderate-certainty evidence. Wearing masks in the community probably makes little or no difference to the outcome of laboratory-confirmed influenza/SARS-CoV-2 compared to not wearing masks (RR 1.01, 95% CI 0.72 to 1.42; 6 trials, 13,919 participants; moderate-certainty evidence). Harms were rarely measured and poorly reported (very low-certainty evidence). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). We are very uncertain on the effects of N95/P2 respirators compared with medical/surgical masks on the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; 3 trials, 7779 participants; very low-certainty evidence). N95/P2 respirators compared with medical/surgical masks may be effective for ILI (RR 0.82, 95% CI 0.66 to 1.03; 5 trials, 8407 participants; low-certainty evidence). Evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; 5 trials, 8407 participants; moderate-certainty evidence). Restricting pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies (very low-certainty evidence).  One previously reported ongoing RCT has now been published and observed that medical/surgical masks were non-inferior to N95 respirators in a large study of 1009 healthcare workers in four countries providing direct care to COVID-19 patients.  Hand hygiene compared to control Nineteen trials compared hand hygiene interventions with controls with sufficient data to include in meta-analyses. Settings included schools, childcare centres and homes. Comparing hand hygiene interventions with controls (i.e. no intervention), there was a 14% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.86, 95% CI 0.81 to 0.90; 9 trials, 52,105 participants; moderate-certainty evidence), suggesting a probable benefit. In absolute terms this benefit would result in a reduction from 380 events per 1000 people to 327 per 1000 people (95% CI 308 to 342). When considering the more strictly defined outcomes of ILI and laboratory-confirmed influenza, the estimates of effect for ILI (RR 0.94, 95% CI 0.81 to 1.09; 11 trials, 34,503 participants; low-certainty evidence), and laboratory-confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials, 8332 participants; low-certainty evidence), suggest the intervention made little or no difference. We pooled 19 trials (71, 210 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. Pooled data showed that hand hygiene may be beneficial with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.83 to 0.94; low-certainty evidence), but with high heterogeneity. In absolute terms this benefit would result in a reduction from 200 events per 1000 people to 178 per 1000 people (95% CI 166 to 188). Few trials measured and reported harms (very low-certainty evidence). We found no RCTs on gowns and gloves, face shields, or screening at entry ports.

AUTHORS' CONCLUSIONS

The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions. There were additional RCTs during the pandemic related to physical interventions but a relative paucity given the importance of the question of masking and its relative effectiveness and the concomitant measures of mask adherence which would be highly relevant to the measurement of effectiveness, especially in the elderly and in young children. There is uncertainty about the effects of face masks. The low to moderate certainty of evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of RCTs did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness, and although this effect was also present when ILI and laboratory-confirmed influenza were analysed separately, it was not found to be a significant difference for the latter two outcomes. Harms associated with physical interventions were under-investigated. There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs.

Transmission of SARS-CoV-2 in the workplace: Key findings from a rapid review of the literature

At the beginning of the COVID-19 pandemic, the primary route of transmission of the SARS-CoV-2 virus was not well understood. Research gathered from other respiratory infectious diseases, including other coronaviruses, was the basis for the initial perceptions for transmission of SARS-CoV-2. To better understand transmission of SARS-CoV-2, a rapid literature review was conducted from literature generated March 19, 2020, through September 23, 2021. 18,616 unique results were identified from literature databases and screened. Of these, 279 key articles were reviewed and abstracted covering critical topics such as environmental/workplace monitoring, sampling and analytical method evaluation, and the ability of the virus to remain intact and infectious during sampling. This paper describes the results of the rapid literature review, which evaluated pathways that contribute to transmission as well as the strengths and limitations of current sampling approaches. This review also evaluates how different factors, including environmental conditions and surface characteristics, could impact the transmission potential of SARS-CoV-2. A continual rapid review in the midst of a pandemic proved particularly useful for quickly understanding the transmission parameters of the virus and enabled us to comprehensively assess literature, respond to workplace questions, and evaluate our understanding as the science evolved. Air and surface sampling with the accompanying analytical methods were not generally effective in recovering SARS-CoV-2 viable virus or RNA in many likely contaminated environments. In light of these findings, the development of validated sampling and analysis methods is critical for determining worker exposure to SARS-CoV-2 and to assess the impact of mitigation efforts.

SARS-CoV-2 Aerosol and Surface Detections in COVID-19 Testing Centers and Implications for Transmission Risk in Public Facing Workers

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and resulting COVID-19 (coronavirus disease 2019) pandemic have required mass diagnostic testing, often taking place in testing sites within hospitals, clinics, or at satellite locations. To establish the potential of SARS-CoV-2 aerosol transmission and to identify junctures during testing that result in increased viral exposure, aerosol and surface samples were examined for the presence of SARS-CoV-2 RNA from locations within Nebraska Medicine COVID-19 testing and vaccine clinics. Aerosols containing SARS-CoV-2 RNA detected within clinics suggest viral shedding from infected individuals. SARS-CoV-2 RNA detection in aerosol samples was shown to correlate with clinic operation and patient infection, as well as with community infection findings. Additionally, SARS-CoV-2 RNA was detected in surface samples collected from clinics. The presence of SARS-CoV-2 RNA in aerosols in these clinics supports the continued use of respiratory protection and sanitization practices for healthcare workers, and other workers with public facing occupations.

A robotic arm for safe and accurate control of biomedical equipment during COVID-19

Purpose

Hospital facilities and social life, along with the global economy, have been severely challenged by COVID-19 since the World Health Organization (WHO) declared it a pandemic in March 2020. Since then, countless ordinary citizens, as well as healthcare workers, have contracted the virus by just coming into contact with infected surfaces. In order to minimise the risk of getting infected by contact with such surfaces, our study aims to design, prototype, and test a new device able to connect users, such as common citizens, doctors or paramedics, with either common-use interfaces (e.g., lift and snack machine keyboards, traffic light push-buttons) or medical-use interfaces (e.g., any medical equipment keypad).

Method

To this purpose, the device was designed with the help of Unified Modelling Language (UML) schemes, and was informed by a risk analysis, that highlighted some of its essential requirements and specifications. Consequently, the chosen constructive solution of the robotic system, i.e., a robotic-arm structure, was designed and manufactured using computer-aided design and 3D printing.

Result

The final prototype included a properly programmed micro-controller, linked via Bluetooth to a multi-platform mobile phone app, which represents the user interface. The system was then successfully tested on different physical keypads and touch screens. Better performance of the system can be foreseen by introducing improvements in the industrial production phase.

Conclusion

This first prototype paves the way for further research in this area, allowing for better management and preparedness of next pandemic emergencies.

Droplet nuclei are generated during colonoscopy and are decreased by the use of carbon dioxide and water immersion technique

OBJECTIVES

The COVID-19 pandemic has raised concerns on whether colonoscopies (CS) carry a transmission risk. The aim was to determine whether CS are aerosol-generating procedures.

METHODS

This was a prospective observational trial including all patients undergoing CS at the Prince of Wales Hospital from 1 June to 31 July 2020. Three particle counters were placed 10 cm from each patient's anus and near the mouth of endoscopists and nurses. The particle counter recorded the number of particles of size 0.3, 0.5, 0.7, 1, 5, and 10 μm. Patient demographics, seniority of endoscopists, use of CO₂ and water immersion technique, and air particle count (particles/cubic foot, dCF) were recorded. Multilevel modeling was used to test all the hypotheses with a post-hoc analysis.

RESULTS

A total of 117 patients were recruited. During CS, the level of 5 μm and 10 μm were significantly higher than the baseline period (P = 0.002). Procedures performed by trainees had a higher level of aerosols when compared to specialists (0.3 μm, P < 0.001; 0.5 μm and 0.7 μm, P < 0.001). The use of CO₂ and water immersion techniques had significantly lower aerosols generated when compared to air (CO₂ : 0.3, 0.5, and 0.7 μm: P < 0.001; water immersion: 0.3 μm: P = 0.048; 0.7 μm: P = 0.03). There were no significant increases in any particle sizes during the procedure at the endoscopists' and nurses' mouth. However, 8/117 (6.83%) particle count tracings showed a simultaneous surge of all particle sizes at the patient's anus and endoscopists' and nurses' level during rectal extubation.

CONCLUSION

Colonoscopy generates droplet nuclei especially during rectal extubation. The use of CO₂ and water immersion techniques may mitigate these risks.

Opportunistic etiological agents causing lung infections: emerging need to transform lung-targeted delivery

Lung diseases continue to draw considerable attention from biomedical and public health care agencies. The lung with the largest epithelial surface area is continuously exposed to the external environment during exchanging gas. Therefore, the chances of respiratory disorders and lung infections are overgrowing. This review has covered promising and opportunistic etiologic agents responsible for lung infections. These pathogens infect the lungs either directly or indirectly. However, it is difficult to intervene in lung diseases using available oral or parenteral antimicrobial formulations. Many pieces of research have been done in the last two decades to improve inhalable antimicrobial formulations. However, very few have been approved for human use. This review article discusses the approved inhalable antimicrobial agents (AMAs) and identifies why pulmonary delivery is explored. Additionally, the basic anatomy of the respiratory system linked with barriers to AMA delivery has been discussed here. This review opens several new scopes for researchers to work on pulmonary medicines for specific diseases and bring more respiratory medication to market.