Transmission Of Respiratory Infections Research Articles

Social contacts in Switzerland during the COVID-19 pandemic: insights from the CoMix study

To mitigate the spread of SARS-CoV-2, the Swiss government enacted restrictions on social contacts from 2020 to 2022. In addition, individuals changed their social contact behavior to limit the risk of COVID-19. In this study, we aimed to investigate the changes in social contact patterns of the Swiss population.As part of the CoMix study, we conducted a survey consisting of 24 survey waves from January 2021 to May 2022. We collected data on social contacts and constructed contact matrices for the age groups 0-4, 5-14, 15-29, 30-64, and 65 years and older. We estimated the change in contact numbers during the COVID-19 pandemic to a synthetic pre-pandemic contact matrix. We also investigated the association of the largest eigenvalue of the social contact and transmission matrices with the stringency of pandemic measures, the effective reproduction number (Re), and vaccination uptake.During the pandemic period, 7,084 responders reported an average number of 4.5 contacts (95% confidence interval, CI: 4.5-4.6) per day overall, which varied by age and survey wave. Children aged 5-14 years had the highest number of contacts with 8.5 (95% CI: 8.1-8.9) contacts on average per day and participants that were 65 years and older reported the fewest (3.4, 95% CI: 3.2-3.5) per day. Compared with the pre-pandemic baseline, we found that the 15-29 and 30-64 year olds had the largest reduction in contacts. We did not find statistically significant associations between the largest eigenvalue of the social contact and transmission matrices and the stringency of measures, Re, or vaccination uptake.The number of social contacts in Switzerland fell during the COVID-19 pandemic and remained below pre-pandemic levels after contact restrictions were lifted. The collected social contact data will be critical in informing modeling studies on the transmission of respiratory infections in Switzerland and to guide pandemic preparedness efforts.

Reducing Transmission of Airborne Respiratory Pathogens: A New Beginning as the COVID-19 Emergency Ends.

In response to the COVID-19 pandemic, new evidence-based strategies have emerged for reducing transmission of respiratory infections through management of indoor air. This paper reviews critical advances that could reduce the burden of disease from inhaled pathogens and describes challenges in their implementation. Proven strategies include assuring sufficient ventilation, air cleaning by filtration, and air disinfection by germicidal ultraviolet (UV) light. Layered intervention strategies are needed to maximize risk reduction. Case studies demonstrate how to implement these tools while also revealing barriers to implementation. Future needs include standards designed with infection resilience and equity in mind, buildings optimized for infection resilience among other drivers, new approaches and technologies to improve ventilation, scientific consensus on the amount of ventilation needed to achieve a desired level of risk, methods for evaluating new air-cleaning technologies, studies of their long-term health effects, workforce training on ventilation systems, easier access to federal funds, demonstration projects in schools, and communication with the public about the importance of indoor air quality and actions people can take to improve it. https://doi.org/10.1289/EHP13878.

Riboflavin based setup as an alternative method for a preliminary screening of face mask filtration efficiency

Face masks are essential in reducing the transmission of respiratory infections and bacterial filtration efficiency, a key parameter of mask performances, requires the use of Staphylococcus aureus and specialised staff. This study aims to develop a novel method for a preliminary screening of masks or materials filtration efficiency by a green, easy and rapid setup based on the use of a riboflavin solution, a safe autofluorescent biomolecule. The proposed setup is composed of a commercial aerosol generator commonly used for aerosol therapy, custom 3D printed aerosol chamber and sample holder, a filter for downstream riboflavin detection and a vacuum pump. The filtration efficiency of four different masks was assessed using the riboflavin-based setup and the bacterial filtration efficiency (BFE). The averaged filtration efficiency values, measured with both methods, were similar but were higher for the riboflavin-based setup (about 2% for all tested samples) than bacterial filtration efficiency. Considering the good correlation, the riboflavin-based setup can be considered validated as an alternative method to bacterial filtration efficiency for masks and related materials fabrics filtration efficiency screening but This study aims to develop a novel method for a preliminary screening of masks or materials filtration efficiency by a green, easy and rapid setup based on the use of a riboflavin solution, a safe autofluorescent biomolecule, but not to replace regulation approaches. The proposed setup can be easily implemented at low price, is more rapid and eco-friendly and can be performed in chemical-physical laboratories without the needing of biosafety laboratory and specialised operators.

Upper Respiratory Tract Infection and Paraneuronal Transmission of SARS-CoV-2

Upper Respiratory Tract Infection and Paraneuronal Transmission of SARS-CoV-2

Respiratory infection transmission risk and indoor air quality at outpatient departments and emergency treatment units of Sri Lankan teaching hospitals.

Indoor carbon dioxide (CO2) concentration has been used as a proxy of the degree of ventilation and, by extension, as an indicator of the risk of contracting respiratory infections. No publications exist regarding indoor air quality (IAQ) parameters of Sri Lankan hospitals.We measured the levels of CO2 and seven other IAQ parameters during morning rush hours for three days, in outpatient departments (OPDs) and emergency treatment units (ETUs) of all 21 teaching hospitals of Sri Lanka. We measured the same parameters of outdoor air also. We calculated the mean values of those parameters. We looked for correlations between outdoors and OPD and ETU levels of selected air quality parameters.The average CO2 levels of outdoors, OPDs and ETUs respectively were 514ppm (ppm = parts per million), 749ppm and 795ppm. The average levels of PM2.5 (particulate matter with diameters <2.5μm) outdoors, OPDs and ETUs respectively, were 28.7μg/m3,32μg/m3 and 25.6 μg/m3. The average levels of PM10 (particulate matter with diameters <10μm) outdoors, OPDs and ETUs respectively, were 49.4μg/m3, 55.5μg/m3 and 47.9 μg/m3. The median levels of formaldehyde outdoors, OPDs and ETUs respectively, were 0.03mg/m3, 0.04mg/m3 and 0.08mg/m3. The median levels of total volatile organic compounds (VOC) outdoors, OPDs and ETUs respectively were 0.12mg/m3, 0.19mg/m3 and 0.38mg/m3.CO2 levels of air in OPDs and ETUs generally were below the national ceilings but above the ceilings used by some developed countries. Outdoors, OPDs and ETUs air contain PM10, PM2.5 levels higher than WHO ceilings, although below the national ceilings. VOC and formaldehyde levels are generally below the national ceilings. Air in OPDs and ETUs is hotter and humid than national ceilings. Outdoor PM10, PM2.5 levels influence OPDs and ETUs levels. We propose methods to reduce the risk of nosocomial respiratory infections and to improve IAQ of Sri Lankan OPDs and ETUs.

Airborne transmission risks of tuberculosis and COVID-19 in schools in South Africa, Switzerland, and Tanzania: Modeling of environmental data.

The COVID-19 pandemic renewed interest in airborne transmission of respiratory infections, particularly in congregate indoor settings, such as schools. We modeled transmission risks of tuberculosis (caused by Mycobacterium tuberculosis, Mtb) and COVID-19 (caused by SARS-CoV-2) in South African, Swiss and Tanzanian secondary schools. We estimated the risks of infection with the Wells-Riley equation, expressed as the median with 2.5% and 97.5% quantiles (credible interval [CrI]), based on the ventilation rate and the duration of exposure to infectious doses (so-called quanta). We computed the air change rate (ventilation) using carbon dioxide (CO2) as a tracer gas and modeled the quanta generation rate based on reported estimates from the literature. The share of infectious students in the classroom is determined by country-specific estimates of pulmonary TB. For SARS-CoV-2, the number of infectious students was estimated based on excess mortality to mitigate the bias from country-specific reporting and testing. Average CO2 concentration (parts per million [ppm]) was 1,610 ppm in South Africa, 1,757 ppm in Switzerland, and 648 ppm in Tanzania. The annual risk of infection for Mtb was 22.1% (interquartile range [IQR] 2.7%-89.5%) in South Africa, 0.7% (IQR 0.1%-6.4%) in Switzerland, and 0.5% (IQR 0.0%-3.9%) in Tanzania. For SARS-CoV-2, the monthly risk of infection was 6.8% (IQR 0.8%-43.8%) in South Africa, 1.2% (IQR 0.1%-8.8%) in Switzerland, and 0.9% (IQR 0.1%-6.6%) in Tanzania. The differences in transmission risks primarily reflect a higher incidence of SARS-CoV-2 and particularly prevalence of TB in South Africa, but also higher air change rates due to better natural ventilation of the classrooms in Tanzania. Global comparisons of the modeled risk of infectious disease transmission in classrooms can provide high-level information for policy-making regarding appropriate infection control strategies.

Genetic diversity and molecular analysis of human influenza virus among pilgrims during Hajj

The risk of transmission of respiratory tract infections is considerably enhanced at mass gathering (MG) religious events. Hajj is an annual Islamic MG event with approximately 3 million Muslim pilgrims from over 180 countries concentrated in Makkah, Saudi Arabia. This study aimed to investigate the genetic diversity of influenza viruses circulating among pilgrims during the Hajj pilgrimage. We performed a cross-sectional analytical study where nasopharyngeal swabs (NPs) from pilgrims with respiratory tract illnesses presenting to healthcare facilities during the 2019 Hajj were screened for influenza viruses. Influenza A subtypes and influenza B lineages were determined by multiplex RT–PCR for positive influenza samples. The phylogenetic analysis was carried out for the hemagglutination (HA) gene. Out of 185 nasopharyngeal samples, 54 were positive for the human influenza virus. Of these, 27 were influenza A H1N1 and 19 H3N2, 4 were untypable influenza A, and 4 were influenza B. Phylogenetic analysis revealed that the H1N1 and H3N2 strains differentiated into different and independent genetic groups and formed close clusters with selected strains of influenza viruses from various locations. To conclude, this study demonstrates a high genetic diversity of circulating influenza A subtypes among pilgrims during the Hajj Season. There is a need for further larger studies to investigate in-depth the genetic characteristics of influenza viruses and other respiratory viruses during Hajj seasons.

Number of children in the household influences respiratory morbidities in children with bronchopulmonary dysplasia in the outpatient setting.

Bronchopulmonary dysplasia (BPD), a common complication of prematurity, is associated with outpatient morbidities, including respiratory exacerbations. Daycare attendance is associated with increased rates of acute and chronic morbidities in children with BPD. We sought to determine if additional children in the household conferred similar risks for children with BPD. The number of children in the household and clinical outcomes were obtained via validated instruments for 933 subjects recruited from 13 BPD specialty clinics in the United States. Clustered logistic regression models were used to test for associations. The mean gestational age of the study population was 26.5 ± 2.2 weeks and most subjects (69.1%) had severe BPD. The mean number of children in households (including the subject) was 2.1 ± 1.3 children. Each additional child in the household was associated with a 13% increased risk for hospital admission, 13% increased risk for antibiotic use for respiratory illnesses, 10% increased risk for coughing/wheezing/shortness of breath, 14% increased risk for nighttime symptoms, and 18% increased risk for rescue medication use. Additional analyses found that the increased risks were most prominent when there were threeor more other children in the household. We observed that additional children in the household were a risk factor for adverse respiratory outcomes. We speculate that secondary person-to-person transmission of respiratory viral infections drives this finding. While this risk factor is not easily modified, measures do exist to mitigate this disease burden. Further studies are needed to define best practices for mitigating this risk associated with household viral transmission.

Regional differences in historical diphtheria and scarlet fever notification rates in The Netherlands, 1905-1925: a spatial-temporal analysis.

We describe how rates of two frequently occurring notifiable diseases-diphtheria and scarlet fever-varied between regions of The Netherlands in the early twentieth century, and identify potential factors underlying this variation. Digitized weekly mandatory notification data for 1905-1925, municipality level, were aggregated into 27 'spatial units' defined by unique combinations of province and population density category (high: more than 4500; mid : 1250-4500; low: less than 1250 inhabitants km-2). Generalized additive regression models were fitted to estimate the associations between notification rates and population density, infant mortality rate and household income, while adjusting for temporal trends per spatial unit. Annual per capita notification rates for both diphtheria and scarlet fever tended to rise from the beginning of the period 1905-1925 until peaking around 1918/1919. Adjusted diphtheria notification rates were higher for high- and mid- compared with low-density municipalities (by 71.6 cases per 100 000, 95% confidence interval (CI) : 52.7-90.5; 39.0/100 k, 95% CI : 24.7-53.3, respectively). Scarlet fever showed similar associations with population density (35.7 cases per 100 000, 95% CI : 9.4-62.0; 21.4/100 k, 95% CI: 1.5-41.3). There was considerable spatial variation in notification rates for both diseases in early twentieth century Netherlands, which could partly be explained by factors capturing variation in living conditions and socio-economic circumstances. These findings aid understanding of contemporary respiratory infection transmission.

Targeted Hygiene reduces surface transmission and infection risk for respiratory viruses

Abstract Background In public spaces, the importance of surface contamination in the transmission of respiratory viruses has been debated. This study aimed to compare the spread of a surrogate virus in a hotel lobby before and after a Targeted Hygiene intervention, and to quantify the reduction in risk of infection from respiratory diseases. Methods In a working hotel lobby, 13 fomites were seeded with a bacteriophage (Phi-X174) tracer at 8 am; 4 hours later 25 surfaces were swabbed to determine baseline tracer distribution and contamination levels. This was then repeated with the addition of a pre-determined Targeted Hygiene intervention performed 2 hours after seeding. Four replicate baseline and intervention trials were conducted, and data were compared for statistically significant (p &amp;lt; 0.05) differences. Risk of infection was estimated via Quantitative Microbial Risk Assessment modelling. Results Following the Targeted Hygiene intervention there was a significant reduction in the spread of the tracer (contamination of 13% of sampled surfaces vs. 50% at baseline). Tracer concentrations (PFU/site) were significantly lower overall (9.1E+02 PFU vs. 5.8E+04 PFU, p &amp;lt; 0.0001), including surfaces that had not been disinfected. Our model estimates that the risk of infection from common respiratory viruses via surface transmission was reduced by 97%. Conclusions Extensive spread of surface contamination can occur in a hotel lobby in as little as 4 hours. This study demonstrates how a Targeted Hygiene intervention can significantly disrupt the journey of the germ, even on surfaces not cleaned and disinfected, resulting in a consequent reduction of infection risk via surface transmission of common respiratory infections. This demonstrates the value of carrying out effective hygiene interventions to those managing commercial spaces. Key messages • Targeted Hygiene can significantly reduce the spread of respiratory pathogens via surface transmission, providing a means for facilities managers to achieve high standards using a targeted approach. • The Targeted Hygiene approach can significantly reduce the risk of infection from common respiratory viruses via surface transmission in public spaces.

The Rise of Electroactive Materials in Face Masks for Preventing Virus Infections.

Air-transmitted pathogens may cause severe epidemics, posing considerable threats to public health and safety. Wearing a face mask is one of the most effective ways to prevent respiratory virus infection transmission. Especially since the new coronavirus pandemic, electroactive materials have received much attention in antiviral face masks due to their highly efficient antiviral capabilities, flexible structural design, excellent sustainability, and outstanding safety. This review first introduces the mechanism for preventing viral infection or the inactivation of viruses by electroactive materials. Then, the applications of electrostatic-, conductive-, triboelectric-, and microbattery-based materials in face masks are described in detail. Finally, the problems of various electroactive antiviral materials are summarized, and the prospects for their future development directions are discussed. In conclusion, electroactive materials have attracted great attention for antiviral face masks, and this review will provide a reference for materials scientists and engineers in antiviral materials and interfaces.

Real-World Efficacy of N95, Surgical, and Cloth Masks in Mitigating SARS-CoV-2 Respiratory Infections: A Comprehensive Comparative Study

The effectiveness of different types of masks in mitigating respiratory infections, particularly those caused by SARS-CoV-2, has been a topic of significant interest during the COVID-19 pandemic. In this study, we conducted a comprehensive comparative analysis of the real-world efficacy of N95, surgical, and cloth masks in reducing the transmission of respiratory infections. Using a large sample size and rigorous data collection methods, we evaluated the protective capabilities of each mask type by assessing the number of infections among individuals wearing these masks in various settings. Our findings reveal that N95 masks exhibited the highest level of protection, followed by surgical masks and cloth masks. However, even cloth masks provided a significant level of protection compared to no mask usage. The results of our study underscore the importance of widespread mask usage as a critical public health measure to control the spread of respiratory infections. These findings have significant implications for public health policies and highlight the need for continued adherence to mask-wearing practices.

A single-arm, prospective study comparing translaryngeal ultrasonography with direct visualisation by flexible laryngoscopy for vocal cord assessment in patients undergoing oesophagectomy or mediastinoscopy.

Translaryngeal ultrasonography (TLUSG) for diagnosis of vocal cord palsy, a relatively new, safe and noninvasive bedside technique with minimal risk of respiratory infection transmission, has been effective in patients with thyroid disease. We studied its use as an alternative method to visual inspection by flexible laryngoscopy (FL) for vocal cord assessment in patients undergoing thoracic surgeries. After Institutional Ethics Committee approval and trial registration, in this single-arm, prospective study, the vocal cord function of 110 patients who underwent either total oesophagectomy or mediastinoscopy was assessed immediately after extubation by both FL and TLUSG. A follow-up assessment was done by laryngoscopy using Hopkin's endoscope (HL) and a repeat TLUSG. The primary outcome was the concordance between direct visualisation (FL or HL) and TLUSG. Vocal cords were successfully visualised by TLUSG in 90% of male and all female patients. Findings of FL and TLUSG done at the first assessment matched in 89 (86.4%) out of 103 patients, and the degree of concordance was 0.69 (95% confidence interval [CI] =0.52-0.83). At the second assessment, HL and TLUSG findings matched in 83 (94.3%) out of 88 patients, and the degree of concordance was 0.89 (95% CI = 0.77-0.98). TLUSG is an effective noninvasive alternative to direct visualisation for vocal cord assessment in both male and female patients undergoing thoracic surgery.

Inequalities in access to paid sick leave among workers in England and Wales.

It is poorly understood which workers lack access to sick pay in England and Wales. This evidence gap has been of particular interest in the context of the Covid-19 pandemic given the relationship between presenteeism and infectious disease transmission. This cross-sectional analysis (n=8874) was nested within a large community cohort study based across England and Wales (Virus Watch). An online survey in February 2021 asked participants in work if they had access to paid sick leave. We used logistic regression to examine sociodemographic factors associated with lacking access to sick pay. Only 66% (n=5864) of participants reported access to sick pay. South Asian workers (adjusted odds ratio [OR] 1.40, 95% confidence interval [CI] 1.06-1.83) and those from Other minority ethnic backgrounds (OR 2.93, 95% CI 1.54-5.59) were more likely to lack access to sick pay compared to White British workers. Older workers (OR range 1.72 [1.53-1.93]-5.26 [4.42-6.26]), workers in low-income households (OR 2.53, 95% CI 2.15-2.98) and those in transport, trade, and service occupations (OR range 2.03 [1.58-2.61]-5.29 [3.67-7.72]) were also more likely to lack access to sick pay compared respectively to workers aged 25-44, those in high income households and managerial occupations. Unwarranted age and ethnic inequalities in sick pay access are suggestive of labour market discrimination. Occupational differences are also cause for concern. Policymakers should consider expanding access to sick pay to mitigate transmission of Covid-19 and other endemic respiratory infections in the community, and in the context of pandemic preparation.

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

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. 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.

Simulation of acute respiratory viral infections pathogen spread in dentists

Aim. To study the airborne transmission of acute respiratory viral infections (ARVIs) in medical care workers of dental clinics.Materials and Methods. We developed a simulation model in which the bacteriophage E. coli, which is a part of the drug "Intesti-bacteriophage", was used as a model of the virus. The host bacterium was Escherichia coli strain M-17, which is part of the Kolibakterin drug. The phage titer according to Appelman was 10-5 plaque-forming units per mL. The experiment was conducted in outpatient care dental office with the participation of medical care workers and implied the contamination of the dental dummy oral cavity by the bacteriophage (A-Dec Simulator REF: 4820) during the treatment of tooth decay by means of aerosol-generating technologies and further detection of the bacteriophage in the environment. Bacteriophage spread was evaluated in 5 series of experiments by collecting the samples from dental office air (n = 50), surfaces of equipment (n = 90), and personal protective equipment of a dentist (n = 80).Results. We found an intensive contamination by bacteriophages during the treatment of tooth decay with the use of aerosol-generating technologies. Phage was isolated in all air samples in the treatment area (100.00% [95% CI 47.82-134.48]) and in 20% of samples at a distance of 160 cm (near the exit). Bacteriophages spread by air currents contaminated the personal protective equipment: protective glasses, gloves, and sleeves of a robe in 100.00% [95% CI 47.82-134.48]) of samples. We have also found a frequent contamination of the inner surface of glasses (40.00% [95% CI 5.27-85.34]) and a medical mask (80.00% [95% CI 28.36-99.49]).Conclusion. We developed a model to study the airborne transmission of ARVI pathogens spread during dental care. Intensive phage contamination of the dental office air and personal protective equipment has been established. A detailed study of the airborne transmission of ARVIs is necessary to improve their prevention in dental workers.

Advantages and disadvantages of maintaining the mandatory use of masks in health centers and nursing homes in Spain. How and when is it justified to maintain it?

We address the advantages and disadvantages of maintaining the mandatory use of masks in health centers and nursing homes in the current epidemiological situation in Spain and after the declaration of the World Health Organization on May 5, 2023 of the end of COVID-19 as public health emergency. We advocate for prudence and flexibility, respecting the individual decision to wear a mask and emphasizing the need for its use when symptoms suggestive of a respiratory infection appear, in situations of special vulnerability (such as immunosuppression), or when caring for patients with those infections. At present, given the observed low risk of severe COVID-19 and the low transmission of other respiratory infections, we believe that it is disproportionate to maintain the mandatory use of masks in a general way in health centers and nursing homes. However, this could change depending on the results of epidemiological surveillance and it would be necessary to reconsider returning to the obligation in periods with a high incidence of respiratory infections.

SARS-CoV-2 transmission with and without mask wearing or air cleaners in schools in Switzerland: A modeling study of epidemiological, environmental, and molecular data.

Growing evidence suggests an important contribution of airborne transmission to the overall spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), in particular via smaller particles called aerosols. However, the contribution of school children to SARS-CoV-2 transmission remains uncertain. The aim of this study was to assess transmission of airborne respiratory infections and the association with infection control measures in schools using a multiple-measurement approach. We collected epidemiological (cases of Coronavirus Disease 2019 (COVID-19)), environmental (CO2, aerosol and particle concentrations), and molecular data (bioaerosol and saliva samples) over 7 weeks from January to March 2022 (Omicron wave) in 2 secondary schools (n = 90, average 18 students/classroom) in Switzerland. We analyzed changes in environmental and molecular characteristics between different study conditions (no intervention, mask wearing, air cleaners). Analyses of environmental changes were adjusted for different ventilation, the number of students in class, school and weekday effects. We modeled disease transmission using a semi-mechanistic Bayesian hierarchical model, adjusting for absent students and community transmission. Molecular analysis of saliva (21/262 positive) and airborne samples (10/130) detected SARS-CoV-2 throughout the study (weekly average viral concentration 0.6 copies/L) and occasionally other respiratory viruses. Overall daily average CO2 levels were 1,064 ± 232 ppm (± standard deviation). Daily average aerosol number concentrations without interventions were 177 ± 109 1/cm3 and decreased by 69% (95% CrI 42% to 86%) with mask mandates and 39% (95% CrI 4% to 69%) with air cleaners. Compared to no intervention, the transmission risk was lower with mask mandates (adjusted odds ratio 0.19, 95% CrI 0.09 to 0.38) and comparable with air cleaners (1.00, 95% CrI 0.15 to 6.51). Study limitations include possible confounding by period as the number of susceptible students declined over time. Furthermore, airborne detection of pathogens document exposure but not necessarily transmission. Molecular detection of airborne and human SARS-CoV-2 indicated sustained transmission in schools. Mask mandates were associated with greater reductions in aerosol concentrations than air cleaners and with lower transmission. Our multiple-measurement approach could be used to continuously monitor transmission risk of respiratory infections and the effectiveness of infection control measures in schools and other congregate settings.

Aerosol generation and risk of transmission of acute respiratory infections: A systematic review

Aerosol generation and risk of transmission of acute respiratory infections: A systematic review

Effect of the coronavirus disease 2019 pandemic on paediatric bilateral myringotomy and tube insertion rates in New Brunswick, Canada.

To assess the effect of the coronavirus disease 2019 pandemic on paediatric bilateral myringotomy and tube insertion rates in New Brunswick, Canada. All paediatric bilateral myringotomy and tube insertion cases from 1 July 2015 through 30 June 2021 were provided by New Brunswick Medicare. The numbers of otolaryngologists, cataract surgical procedures, total hip arthroplasties and thyroidectomies were collected to assess the availability of operating theatres and otolaryngologists. Negative binomial logarithmic regressions were used for analyses. Of the 5175 paediatric bilateral myringotomy and tube insertion cases that were included, the bilateral myringotomy and tube insertion rate significantly decreased by 2.9 times (p < 0.001) during the pandemic. Thyroidectomies, cataract surgical procedures and total hip arthroplasties did not significantly decrease. The number of otolaryngologists increased (20 vs 16-17). Paediatric bilateral myringotomy and tube insertion rates significantly decreased during the pandemic. This cannot be accounted for by reduced otolaryngologists or operating theatre availability. The paediatric bilateral myringotomy and tube insertion rate decrease is likely due to public health measures reducing the transmission of upper respiratory tract infections, resulting in fewer indications for paediatric bilateral myringotomy and tube insertion.