The Effectiveness of Face Masks in Preventing COVID-19 Transmission: A Systematic Review.

INTRODUCTION: Since the beginning of the COVID-19 pandemic, face masks have been among the cornerstones of COVID-19 prevention. Therefore, evaluating their preventive effects against COVID-19 is crucial. This review aimed to systematically search for the systematic review articles that explored the role of various types of face masks in preventing COVID-19. METHODS: We browsed the keywords of this study in the online databases of Scopus, Web of Science, PubMed, and Cochrane on 10th January 2023 and retrieved all the relevant systematic review articles. The records were downloaded into an Endnote file, and the duplicates were removed. A two-step screening process consisting of title/abstract and full-text screenings was conducted to select the most relevant articles. To ensure the validity and reliability of the results, this study adhered to the PRISMA protocol. RESULTS: A total of 28 systematic reviews were included in this review. Most studies found that face masks are beneficial against viral respiratory infections, such as COVID-19. Different types of masks were evaluated in included studies. It appeared that mask efficacy depends on the material, layers, fitting on the face and user compliance. N 95 respirator had maximum efficacy, especially when used continuously. CONCLUSION: Face masks have a beneficial effect against COVID-19. Home masks are less protective than surgical masks or N95 personal breathing masks. Besides, the use of masks may elicit a false sense of security in people, which may lead to poor hand hygiene and violation of social distancing. Therefore, the necessary training should be provided to the public to increase awareness and encourage the right practice of using the mask, emphasizing the preventive effects of washing hands, social distancing, and using a face mask against COVID-19.

Effect of an N95 respirator and a surgical mask-covered N95 on the cardiovascular responses of dentists treating paediatric patients: A crossover clinical trial.

BACKGROUND: The studies on cardiovascular alterations when using an N95 respirator or surgical mask-covered N95 during dental treatments are limited. AIM: To investigate and compare the cardiovascular responses of dentists treating paediatric patients while wearing an N95 respirator or a surgical mask-covered N95. DESIGN: This was a crossover clinical trial in 18 healthy dentists wearing an N95 respirator or surgical mask-covered N95 during the dental treatment of paediatric patients. Oxygen saturation (SpO2 ), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were monitored at baseline, intraoperation, and postoperation. The data were analyzed using the generalized estimating equation. RESULTS: The mean SpO2 , HR, SBP, DBP, and MAP significantly changed from baseline up to the end of the procedures after wearing an N95 by 3.1%, 19.3%, 11.5%, 17.7%, and 13.8% and after wearing a surgical mask-covered N95 by 3.0%, 20.2%, 5.3%, 13.9%, and 8.8%, respectively (p < .05). No significant differences in these values were found between groups (p > .05). CONCLUSIONS: N95 respirators and surgical mask-covered N95s significantly impact the cardiovascular responses of dentists treating paediatric patients with no differences between the two types of masks.

Aerosol-Generating Medical Procedures: Controversies in Definition, Risks, and Mitigation Strategies

An aerosol-generating medical procedure (AGMP) is any procedure performed on a patient that can induce the production of aerosols of various sizes, including droplet nuclei. AGMPs have become a subject of increasing interest during the COVID-19 pandemic for two critical reasons. First, AGMP likely increases the risk of transmission from patients infected with respiratory infections to healthcare personnel and other patients in their environment. Second, special risk mitigation strategies, including selection of specific types of personal protective equipment and environmental controls, are necessary to protect staff during the performance of AGMPs. Heightened awareness for AGMPs began during the 2003 severe acute respiratory syndrome (SARS) pandemic, where it was noted that, in outbreaks, many frontline HCWs had increased risk of contracting the virus related to certain procedures performed on the respiratory tract (Tran et al. PLoS One 7:e35797, 2012). Numerous clinical guidelines were published attempting to categorize and classify the risk associated with various AGMP. However, while numerous procedures have been identified as "aerosol generating, " the scientific evidence for the creation of aerosols associated with these procedures, the burden of potential viable microbes within the created aerosols, and the mechanism of transmission to the host have not been well studied (Davies et al. J Infect Prev 10:122-6, 2009). Almost 20 years later, there are still large gaps in knowledge around AGMPs - what defines them, what is the added risk associated with them, and which strategies are most effective at mitigating the risks associated with them. Here, we summarize the current knowledge around AGMPs including the types, risk, and mitigation strategies. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

N95 masks: skin changes in health professionals in northern Brazil / Máscaras N95: alterações de pele em profissionais de saúde do norte brasileiro / Mascarillas N95: alteraciones en la piel de profesionales de salud en el norte de Brasil

Resumo Objetivo Identificar os fatores associados ao uso de máscara N95 relacionados a alterações de pele entre profissionais de saúde do Norte do Brasil durante a pandemia de COVID-19. Métodos Estudo multicêntrico realizado na região Norte do Brasil no período de outubro a dezembro de 2020, com 1.684 profissionais de saúde que atuaram na assistência à saúde durante a pandemia da COVID-19. Os participantes foram convidados via mídias sociais e as informações coletadas eletronicamente foram armazenadas na plataforma Survey Monkey. Foi usada estatística descritiva para caracterização da amostra, testes de associação (Qui-quadrado), com nível de significância estatística em p < 0,05. Os fatores associados ao uso de máscara N95 relacionados a alterações de pele foram determinados por Regressão Logística Binária, nível de significância de 5% (α = 0,05). Resultados Profissionais de saúde do sexo masculino apresentaram 1,708 mais chances de ter alterações de pele. Outros fatores como, o período de troca de máscara N95, ter atuado em hospital de campanha para COVID-19, terapia intensiva, urgência e emergência e ter recebido alguma capacitação ou curso sobre o COVID-19 foram considerados protetores ao desenvolvimento de alterações de pele, enquanto os principais motivos de troca de máscara N95 foram a umidade, perda de vedação, contaminação, danificação (rasgo). Conclusão Concluiu-se que profissionais de saúde do sexo masculino apresentaram mais chances de ter alterações de pele relacionadas ao uso de máscaras N95. Destacaram-se os fatores protetores e torna-se relevante a realização de estudos de intervenção a fim explorar medidas para prevenção destes tipos de lesões.

Resumen Objetivo Identificar los factores asociados al uso de la mascarilla N95 relacionados con las alteraciones en la piel entre profesionales de salud del norte de Brasil durante la pandemia de COVID-19. Métodos Estudio multicéntrico realizado en la región Norte de Brasil, en el período de octubre a diciembre de 2020, con 1.684 profesionales de salud que actuaron en la asistencia a la salud durante la pandemia de COVID-19. Se convocó a los participantes a través de las redes sociales y la información recopilada electrónicamente fue guardada en la plataforma Survey Monkey. Se utilizó la estadística descriptiva para la caracterización de la muestra, pruebas de asociación (Ji-cuadrado), con un nivel de significación estadística de p < 0,05. Los factores asociados al uso de la mascarilla N95 relacionados con alteraciones en la piel fueron determinados por regresión logística binaria, nivel de significación del 5 % (α = 0,05). Resultados Profesionales de salud de sexo masculino tuvieron 1,708 más posibilidades de presentar alteraciones en la piel. Otros factores como el intervalo de tiempo entre los cambios de mascarillas N95, haber trabajado en hospitales de campaña para COVID-19, cuidados intensivos, urgencias y emergencias y haber realizado alguna capacitación o curso sobre COVID-19 fueron considerados protectores del surgimiento de alteraciones en la piel, mientras que los principales motivos para el cambio de la mascarilla N95 fueron la humedad, la pérdida del sellado, la contaminación y daños (rotura). Conclusión Se concluye que los profesionales de la salud de sexo masculino presentaron más probabilidades de tener alteraciones en la piel relacionadas con el uso de mascarillas N95. Se destacaron los factores protectores y resulta importante la realización de estudios experimentales con la finalidad de explorar medidas para la prevención de este tipo de lesiones.

Abstract Objective To identify the factors associated with N95 mask use related to skin changes among health professionals in northern Brazil during the COVID-19 pandemic. Methods This is a multicenter study carried out in northern Brazil, from October to December 2020, with 1,684 health professionals who worked in health care during the COVID-19 pandemic. Participants were invited via social media and the information collected electronically was stored on the Survey Monkey platform. Descriptive statistics were used to characterize the sample, association tests (chi-square), with statistical significance level at p < 0.05. Factors associated with N95 mask ruse elated to skin changes were determined by Binary Logistic Regression, significance level of 5% (α = 0.05). Results Male health professionals were 1.708 more likely to have skin changes. Other factors such as the N95 mask change period, having worked in a COVID-19 field hospital, intensive care, urgency and emergency and having received some training or course on COVID-19 were considered protective against the development of skin changes, while the main reasons for changing the N95 mask were humidity, loss of seal, contamination, damage (tear). Conclusion We concluded that male health professionals were more likely to have skin changes related to N95 mask use. The protective factors were highlighted and it is relevant to carry out intervention studies in order to explore measures to prevent these types of injuries.

Headache Associated with PPE During COVID-19 Pandemic in Health Care Workers.

PURPOSE: In the pandemic coronavirus disease 2019 (COVID-19), health care workers (HCWs) are at very high risk. Personal protective equipment (PPE) and masks are not only difficult to wear while working but also causes various complications. The present self-administered questionnaire- based study aimed to explore the headache and complications in HCWs on wearing PPE during the COVID-19 pandemic. METHODS: The present study was performed by obtaining a self-administered questionnaire from HCWs, which provides evidence of various complications due to the use of a PPE and mask. RESULTS: Out of a total of 329 respondents, 189(57.45%), 67(20.36%), 238(72.34%), 213(64.74%), 177(53.80%), and 34(10.33%) reported headache, breathlessness, suffocation, nose pain, ear pain, and leg pain respectively. Out of 329 respondents, 47(14.29%) had pre-existing headaches. Headache was significantly high for those who wore PPE for 4-6h (121/133; 87.05%) than that of those who wore up to 4h (18/26; 69.23%). Of the 34(24.46%) required medication who reported headaches wearing PPE. Acetaminophen is quite helpful in most health care workers to decrease headaches. Nose-related complications occur frequently in health care workers after regular shifts for more than 6 days. Gelatinous adhesives patch was a wonderful prophylactic remedy as it was helpful to prevent nose- related complications in 24 HCWs out of 25(96%). CONCLUSIONS: More than half of the HCWs reported headache, suffocation, nose pain, and ear pain. Duration of PPE use of more than 4h is significantly associated with headache. Short duration PPE use prevent HCWs from headache and various ill effects.

Review of the Effect of Continuous Use and Limited Reuse of N95 Respirators on Respirator Fit.

Background: Coronavirus disease 2019 (COVID-19) has led to severe shortages of filtering facepiece respirators (FFRs). As a result, extended use, limited reuse, and FFR decontamination have been utilized to extend the life of single-use FFRs. Although some studies have raised concerns that reuse could affect the FFR's ability to form a seal, no comprehensive literature review of the effect of extended use or limited reuse on FFR seal exists. Objective: The goal of this review was to assess the effect of extended use and reuse on respirator fit, with and without decontamination. Methods: Searches of PubMed and Medrxiv yielded 24 papers that included assessment of fit after extended use or limited reuse on a human. One additional handpicked paper was added. Results: Studies report a wide variation in the number of donnings and doffings before fit failure between different models of respirators. Additionally, while seal checks lack sufficient sensitivity to reliably detect fit failures, individuals who failed fit testing were often able to pass subsequent tests by re-positioning the respirator. Even with failure, respirators often maintained a substantially higher level of fit than a surgical mask, so they may still provide a level of protection in crisis settings. Conclusion: Based on currently available data, this literature review was unable to establish a consensus regarding the amount of time a respirator can be worn or the number of uses before fit failure will occur. Furthermore, variations in reuses before fit failure between different models of N95 respirators limit the ability to offer a comprehensive recommendation of greater than one reuse or a specific amount of wear time.

Efficacy of Surgical Masks Versus N95 Respirators for the Prevention of COVID-19 in Dental Settings: A Systematic Review.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2. (SARS-CoV-2). It spreads mainly through saliva droplets or nasal discharge. Dentists are among the professionals with the greatest risk of contracting and transmitting COVID-19. We compared the efficacy of surgical masks versus N95 respirators in preventing COVID-19 infection in dental settings. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched. Search terms corresponded to a predefined PICOS (patient/population, intervention, comparison, and outcomes) question. The risk of bias was evaluated using AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews-2), ROBIS (Risk of Bias in Systematic Reviews), and Health Evidence tools. A total of 191 articles were screened, and nine of them were further evaluated for eligibility, of which five articles (fulfilled the selection criteria) and were included in this study. Two studies concluded that surgical masks could provide equivalent protection to N95 respirators. Another study found that N95 respirators were superior to surgical masks. The fourth study found that better protection can be achieved when using surgical masks by the aerosol source than when the recipient uses an N95 respirator, while the last study concluded that surgical masks or N95 respirators alone do not provide full protection. Thus, according to this systematic review, N95 respirators provide better protection against COVID-19 infection compared to surgical masks.

Effect of N95 Filtering Facepiece Respirator on Venous Blood Carbon Dioxide Levels and Hemodynamic Changes in Health Care Workers.

Background: N95 filtering facepiece respirators (FFR) are used by health care workers for prevention of airborne infection, and its use has increased manifolds during COVID-19 pandemic. Prolonged use may result in carbon dioxide (CO2) accumulation, affect hemodynamics, and blood gas values. Although arterial blood gas values accurately measure the blood CO2 levels, venous blood gas values also show acceptable correlation. Aim: To evaluate the physiological impact of N95 FFRs on health care workers, including hemodynamic changes and venous blood levels of CO2 during a period of 6 h. Settings and Design: Prospective observational study in a tertiary care hospital. Methods: The study was conducted on 30 health care workers who performed routine duties while wearing N95 FFR. Venous blood gas values (CO2, pH, and bicarbonate) and vitals (respiratory rate, heart rate, blood pressure, and saturation) were noted at baseline, 2 (T2), and 6 h (T6) after wearing the mask. Discomfort level was also measured on a Visual Analogue Scale (VAS) of 1-10. Statistical Analysis: Repeated measures analysis was done using repeated measures ANOVA or Friedman's test. Group comparisons for continuously distributed data were made using independent sample "t" test or Wilcoxon test. Results and Conclusion: Hemodynamic and blood gas values did not change over time. The VAS for discomfort because of respirator use was 1.33 (1.42) at T2 and 2.77 (1.91) at T6. This was a significant increase in discomfort over time (P = 0.001). About 80% of participants experienced discomfort during this period. N95 FFR did not lead to significant alteration in hemodynamics or change in blood gas values after 6 h of continuous usage. However, discomfort significantly increased over time.

Required Personal Protective Equipment for Prehospital Healthcare Provider in COVID-19 Pandemic: A Systematic Review

Aims. Coronavirus Disease 2019 (COVID-19) is a highly contagious disease, and a variety of personal protective equipment (PPE) has been recommended as preventive measures for prehospital emergency personnel, which has led to considerable challenges and a great confusion for the personnel. This review aims to identify different types of PPE required in the care of COVID-19 patients in prehospital emergency system.Material and methods. This study was carried out by searching through databases including: Pubmed, Proqust, Google Scholar, and Cinahl. All articles that recommended different types of PPE against COVID-19 and infectious diseases for prehospital emergency personnel were collected in a table.Results. After carrying out the initial search in the databases, 1,009 studies were obtained and then 16 articles were selected. The findings seem to suggest using equipment including: gloves, face shields (shield/goggles), protective clothes (medical jumpsuit/scrubs), surgical masks, N-95 masks, powered air purifying respirators (PAPR), hair covers, shoe covers and washing up the hands by the emergency medical service (EMS) personnel.Discussion. The scrutiny of the relevant studies showed that each of them advised the EMS personnel to use a number of PPE. The present study highlighted the fact that there are other components of the PPE which can be useful to them.Conclusion. This study identified the most appropriate PPE needed for prehospital emergency personnel against COVID-19, and it is believed that planning for adequate access to this equipment and training on how to use them can significantly help to reduce the infection among the personnel.

Acute effects of different facemasks during High Intensity Interval Training in trained women. A randomized crossover pilot study

The aim of the present investigation was to analyze the acute effect of different facemasks on physiological, perceptual and performance parameters in trained young women during a High Intensity Interval Training (HIIT) on cycle ergometer. Fifteen subjects participated in the study. Heart rate variability, muscle oxygen saturation, lactate concentration and comfort parameters were measured under 3 conditions: no facemask, surgical and FFP2 facemask. The use of facemasks had no effect on any variable related to oxygen saturation, heart rate variability and cycling power during the HIIT protocol. Only lactate concentration revealed significantly lower values in the No mask condition compared to FFP2 3 min after HIIT (p =.038). Regarding the overall perception and comfort, participants reported greater discomfort when wearing the FFP2 mask compared to the No mask condition (p<.05). On the contrary, the analysis of heart rate variability, revealed significant differences (p<.001) in the Pre compared to the Post exercise for all conditions. The use of surgical or FFP2 facemask during HIIT training does not affect performance during strenuous exercise while perceived comfort appears to be lower with FFP2 masks in physically trained women.

Awareness and Pragmatic Use of Respirators among Dental Healthcare Professionals during COVID-19 Pandemic: A Cross-sectional Study

Aim: This cross-sectional study intends to assess dental healthcare professionals' (DHCPs) knowledge and awareness of the proper use and reuse of respirators. Materials and methods: A hospital-based cross-sectional survey was conducted using a self-administered questionnaire adapted from the Centers for Disease Control and Prevention (CDC) guidelines regarding the use of respirators with the primary objective of cognizance regarding fit testing, use, reuse, and reprocessing. A total of 478 dental professionals, including 192 postgraduate (PG) students, 176 interns, and 110 teaching faculty, participated in the survey. Data were analyzed using descriptive statistics. Results: A cumulative assessment revealed that 56.9% of dental professionals signed in to use level III masks and 29.3% for N95/KN95 respirators. Amongst those individuals using respirators, only 2.9% have got fit testing done. 92.1% (n = 440) were clueless about the various fit testing methods. 75.7% of DHCPs chose rotation base reuse of respirators rather than extended use of respirators. Conclusion: Clear evidence of incognizance among dental professionals regarding respirator use may put the health care professional at risk of infection. The incorporation of respirator training in infection prevention and control programs should be a prerequisite for preventing cross-infection. Clinical significance: There is a definite need for regular training and educational programs among DHCPs on various infection control protocols with the incorporation of respirator training and the terms of use of the respirator. © The Author(s).

Lesões de pele associadas ao uso de respiradores N95 entre profissionais de saúde no Brasil em 2020

Objetivo: investigar a prevalência de lesões de pele e fatores associados ao uso de respiradores N95 entre profissionais de saúde no Brasil. Método: estudo transversal realizado com 11.368 profissionais de saúde por meio de um método de amostragem dirigido por respondentes adaptado para ambientes online. Análises univariadas e multivariadas foram realizadas para investigar a associação entre a variável "lesão de pele com uso de respirador N95” e sexo, categoria profissional, local de trabalho, treinamento, diagnóstico de COVID-19 e disponibilidade suficiente de equipamentos de proteção individual de qualidade. Resultados: a prevalência de lesões cutâneas foi de 61,8%. As mulheres foram 1,203 vezes (IC 95%: 1.154-1.255) mais propensas a desenvolver uma lesão do que os homens. As chances de lesão de pele em psicólogos (RP=0,805;IC 95%: 0,678-0,956) e dentistas (RP=0,884;IC 95%: 0,788-0,992) foram menores quando comparados aos profissionais de Enfermagem. Profissionais com diagnóstico positivo para COVID-19 e que trabalham em Unidade de Cuidados Intensivos têm maior chance de apresentar lesões de pele (RP=1,074;IC 95%: 1,042-1,107);(RP=1,203;IC 95%: 1,168- 1,241), respectivamente. Conclusão: a prevalência de lesões de pele causadas pelo uso do respirador N95 foi de 61,8% e esteve associada ao sexo feminino, categoria profissional, local de trabalho, treinamento, diagnóstico de COVID-19 e disponibilidade suficiente de equipamentos de proteção individual de qualidade.Alternate : Objective: to investigate the prevalence of skin lesions and factors associated with the use of N95 respirators among health professionals in Brazil. Method: cross-sectional study conducted with 11,368 health professionals using a respondent-driven sampling method adapted for online environments. Univariate and multivariate analyses were performed to investigate the association between the "skin lesions with the use of N95 respirators” variable and gender, professional category, workplace, training, COVID-19 diagnosis, and availability of sufficient and high-quality Personal Protective Equipment. Results: the prevalence of skin lesions was 61.8%. Women were 1.203 times (95% CI: 1.154-1.255) more likely to develop a lesion than men. The chances of skin lesions in psychologists (PR=0.805;95% CI: 0.678-0.956) and dentists (PR=0.884;95% CI: 0.788-0.992), were lower when compared to Nursing professionals. Professionals with a positive COVID-19 diagnosis and working in the Intensive Care Unit have an increased chance of presenting skin lesions (PR=1.074;95% CI: 1.042-1.107);(PR=1.203;95% CI: 1.168-1.241), respectively. Conclusion: the prevalence of skin lesions caused by the use of N95 respirators was 61.8% and was associated with female gender, professional category, workplace, training, COVID-19 diagnosis, and availability of sufficient and highquality Personal Protective Equipment.

Wearing N95 masks decreases the odor discrimination ability of healthcare workers: a self-controlled before-after study.

Objective: During the coronavirus disease 2019 (COVID-19) pandemic, the N95 mask is an essential piece of protective equipment for healthcare workers. However, the N95 mask may inhibit air exchange and odor penetration. Our study aimed to determine whether the use of N95 masks affects the odor discrimination ability of healthcare workers. Methods: In our study, all the participants were asked to complete three olfactory tests. Each test involved 12 different odors. The participants completed the test while wearing an N95 mask, a surgical mask, and no mask. The score for each olfactory test was documented. Results: The olfactory test score was significantly lower when the participants wore N95 masks than when they did not wear a mask (7 vs. 10, p < 0.01). The score was also lower when the participants wore N95 masks than surgical masks (7 vs. 8, p < 0.01). Conclusion: Wearing N95 masks decreases the odor discrimination ability of healthcare workers. Therefore, we suggest that healthcare workers seek other clues when diagnosing disease with a characteristic odor.

Possible toxicity of chronic carbon dioxide exposure associated with face mask use, particularly in pregnant women, children and adolescents - A scoping review.

Introduction: During the SARS-CoV-2-pandemic, face masks have become one of the most important ubiquitous factors affecting human breathing. It increases the resistance and dead space volume leading to a re-breathing of CO2. So far, this phenomenon and possible implications on early life has not been evaluated in depth. Method: As part of a scoping review, literature was systematically reviewed regarding CO2 exposure and facemask use. Results: Fresh air has around 0.04% CO2, while wearing masks more than 5 min bears a possible chronic exposure to carbon dioxide of 1.41% to 3.2% of the inhaled air. Although the buildup is usually within the short-term exposure limits, long-term exceedances and consequences must be considered due to experimental data. US Navy toxicity experts set the exposure limits for submarines carrying a female crew to 0.8% CO2 based on animal studies which indicated an increased risk for stillbirths. Additionally, mammals who were chronically exposed to 0.3% CO2 the experimental data demonstrate a teratogenicity with irreversible neuron damage in the offspring, reduced spatial learning caused by brainstem neuron apoptosis and reduced circulating levels of the insulin-like growth factor-1. With significant impact on three readout parameters (morphological, functional, marker) this chronic 0.3% CO2 exposure has to be defined as being toxic. Additional data exists on the exposure of chronic 0.3% CO2 in adolescent mammals causing neuron destruction, which includes less activity, increased anxiety and impaired learning and memory. There is also data indicating testicular toxicity in adolescents at CO2 inhalation concentrations above 0.5%. Discussion: There is a possible negative impact risk by imposing extended mask mandates especially for vulnerable subgroups. Circumstantial evidence exists that extended mask use may be related to current observations of stillbirths and to reduced verbal motor and overall cognitive performance in children born during the pandemic. A need exists to reconsider mask mandates.

Physio-metabolic and clinical consequences of wearing face masks-Systematic review with meta-analysis and comprehensive evaluation.

Background: As face masks became mandatory in most countries during the COVID-19 pandemic, adverse effects require substantiated investigation. Methods: A systematic review of 2,168 studies on adverse medical mask effects yielded 54 publications for synthesis and 37 studies for meta-analysis (on n = 8,641, m = 2,482, f = 6,159, age = 34.8 ± 12.5). The median trial duration was only 18 min (IQR = 50) for our comprehensive evaluation of mask induced physio-metabolic and clinical outcomes. Results: We found significant effects in both medical surgical and N95 masks, with a greater impact of the second. These effects included decreased SpO2 (overall Standard Mean Difference, SMD = -0.24, 95% CI = -0.38 to -0.11, p < 0.001) and minute ventilation (SMD = -0.72, 95% CI = -0.99 to -0.46, p < 0.001), simultaneous increased in blood-CO2 (SMD = +0.64, 95% CI = 0.31-0.96, p < 0.001), heart rate (N95: SMD = +0.22, 95% CI = 0.03-0.41, p = 0.02), systolic blood pressure (surgical: SMD = +0.21, 95% CI = 0.03-0.39, p = 0.02), skin temperature (overall SMD = +0.80 95% CI = 0.23-1.38, p = 0.006) and humidity (SMD +2.24, 95% CI = 1.32-3.17, p < 0.001). Effects on exertion (overall SMD = +0.9, surgical = +0.63, N95 = +1.19), discomfort (SMD = +1.16), dyspnoea (SMD = +1.46), heat (SMD = +0.70), and humidity (SMD = +0.9) were significant in n = 373 with a robust relationship to mask wearing (p < 0.006 to p < 0.001). Pooled symptom prevalence (n = 8,128) was significant for: headache (62%, p < 0.001), acne (38%, p < 0.001), skin irritation (36%, p < 0.001), dyspnoea (33%, p < 0.001), heat (26%, p < 0.001), itching (26%, p < 0.001), voice disorder (23%, p < 0.03), and dizziness (5%, p = 0.01). Discussion: Masks interfered with O2-uptake and CO2-release and compromised respiratory compensation. Though evaluated wearing durations are shorter than daily/prolonged use, outcomes independently validate mask-induced exhaustion-syndrome (MIES) and down-stream physio-metabolic disfunctions. MIES can have long-term clinical consequences, especially for vulnerable groups. So far, several mask related symptoms may have been misinterpreted as long COVID-19 symptoms. In any case, the possible MIES contrasts with the WHO definition of health. Conclusion: Face mask side-effects must be assessed (risk-benefit) against the available evidence of their effectiveness against viral transmissions. In the absence of strong empirical evidence of effectiveness, mask wearing should not be mandated let alone enforced by law. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021256694, identifier: PROSPERO 2021 CRD42021256694.

Ripple effect mitigation capabilities of a hub and spoke distribution network: an empirical analysis of pharmaceutical supply chains in India

In this study, we focus on ripple effect mitigation capability of the Indian pharmaceutical distribution network during disruptions like COVID-19 pandemic. To study the mitigation capabilities, we conduct a multi-layer analysis (network, process, and control levels) using Bayesian network, mathematical optimisation, and discrete event simulation methodologies. This analysis revealed an associative relationship between ripple effect mitigation capabilities and network design characteristics of upstream supply chain entities. Using stochastic optimisation and Lagrangian relaxation, we then find ideal candidates for regional distribution centres at the downstream level. We then integrate these downstream locations with other supply chain entities for building the network optimisation and simulation model to analyse overall performance of the system. We demonstrate utility of our proposed methodology using a case study involving distribution of N95 masks to ‘Jan Aushadhi' (peoples' medicines) stores in India during COVID-19 pandemic. We find that supply chain reconfiguration improves service level to 95.7% and reduces order backlogs by 10.7%. We also find that regional distribution centres and backup supply sources provide overall flexibility and improve occupational health and safety. We further investigate alternate mitigation capabilities through fortification of suppliers' workforce by vaccination. We offer recommendations for policymakers and managers and implications for academic research.

Nosocomial SARS-CoV-2 transmission in multi-bedded hospital cubicles over successive pandemic waves: Lower mortality but wider spread with Omicron despite enhanced infection-prevention measures.

BACKGROUND: Increased transmissibility of severe-acute-respiratory-syndrome-coronavirus-2(SARS-CoV-2) variants, such as the Omicron-variant, presents an infection-control challenge. We contrasted nosocomial transmission amongst hospitalized inpatients across successive pandemic waves attributed to the Delta- and Omicron variants, over a 9-month period in which enhanced-infection-prevention-measures were constantly maintained. METHODS: Enhanced-infection-prevention-measures in-place at a large tertiary hospital included universal N95-usage, routine-rostered-testing (RRT) for all inpatient/healthcare-workers (HCWs), rapid-antigen-testing (RAT) for visitors, and outbreak-investigation coupled with enhanced-surveillance (daily-testing) of exposed patients. The study-period lasted from 21st June 2021-21st March 2022. Chi-square test and multivariate-logistic-regression was utilized to identify factors associated with onward transmission and 28d-mortality amongst inpatient cases of hospital-onset COVID-19. RESULTS: During the Delta-wave, hospital-onset cases formed 2.7% (47/1727) of all COVID-19 cases requiring hospitalisation; in contrast, hospital onset-cases formed a greater proportion (17.7%, 265/1483; odds-ratio, OR = 7.78, 95%CI = 5.65-10.70) during the Omicron-wave, despite universal N95-usage and other enhanced infection-prevention measures that remained unchanged. The odds of 28d-mortality were higher during the Delta-wave compared to the Omicron-wave (27.7%, 13/47, vs. 10.6%, 28/265, adjusted-odds-ratio, aOR = 2.78, 95%CI = 1.02-7.69). Onward-transmission occurred in 21.2% (66/312) of hospital-onset cases; being on enhanced-surveillance (daily-testing) was independently associated with lower odds of onward-transmission (aOR = 0.18, 95%CI = 0.09-0.38). Costs amounted to $USD7141 per-hospital-onset COVID-19 case. CONCLUSION: A surge of hospital-onset COVID-19 cases was encountered during the Omicron-wave, despite continuation of enhanced infection-prevention measures; mortality amongst hospital-onset cases was reduced. The Omicron variant poses an infection-control challenge in contrast to Delta; surveillance is important especially in settings where infrastructural limitations make room-sharing unavoidable, despite the high risk of transmission.

Case study of the Beijing 2022 Olympic Winter Games: Implications for global mass gathering events amidst the COVID-19 pandemic.

Objective: This study aimed to evaluate the public health countermeasures against coronavirus disease 2019 (COVID-19) that are important for organizing mass gathering events (MGEs) during a pandemic and to identify the practices suitable for application at future MGEs. Methods: This study analyzed data from the Beijing 2022 Olympic Winter Games. The aforementioned analysis was conducted from the viewpoints of overseas stakeholders and Chinese residents. The comprehensive set of countermeasures established to prevent the transmission of the COVID-19 pandemic comprised the bubble strategy, the three-layer testing strategy (pre-departure testing, testing at the airport, and daily screening), the mandatory wearing of N95 masks, and mandatory vaccination. Findings: A total of 437 positive cases within the bubble were reported during the Games, of which 60.6% were detected through screening at the airport and 39.4% were detected through routine screening. Nearly, 92.0% of the positive cases were detected within 7 days of arrival in China, and 80.8% of the cases had already been identified before the Opening Ceremony of the Games. Outside the bubble, no Games stakeholders were infected and no spectator contracted COVID-19. The bubble strategy, the three-layer testing strategy, the mandatory wearing of N95 masks, and mandatory vaccination are promising countermeasures to prevent the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during MGEs. Conclusion: Public health countermeasures introduced during the Beijing 2022 Olympic Winter Games were proven to be useful. The success in delivering and organizing the Games instills confidence and leaves a public health legacy for future MGEs amid the pandemic of COVID-19 or future emerging infectious diseases.

Protecting healthcare personnel and patients over 3 years of COVID-19 : Effective protection by masks and hygiene: What else was effective?

Healthcare professionals, particularly those in test centers, laboratories, or specialized COVID-19 wards, are in danger of becoming infected. Patients with special underlying health conditions are at an increased risk of getting very sick, being hospitalized, or dying from COVID-19. Age is a leading risk factor in this context. Currently, FFP2 (Filtering Facepiece 2, European standard), N95 (US standard), and KN95 (Chinese standard) face masks remain the simplest measure of protection. Coronavirus warning apps installed on smartphones have been recommended for anonymous contact tracing and quickly disrupting chains of infection. Preventive testing two to three times per week for healthcare personnel, on the day of hospital admission for patients, and upon facility entry for visitors has been routinely performed or has been requested from external test centers in most medical institutions. However, vaccination is regarded the most effective protective measure against COVID-19. The general recommendation of the World Health Organization is that countries continue to work toward vaccinating at least 70% of their populations, prioritizing the vaccination of 100% of healthcare workers and 100% of the most vulnerable groups, including people who are over 60 years of age and those who are immunocompromised or have underlying health conditions. The most vulnerable individuals among patients and healthcare workers should be identified and then their vaccination status should be checked and, if necessary, optimized by booster administration. In Germany, seasonal and institutional recommendations for individual protection by face masks, for hygiene measures, and for preventive testing must follow the updated coronavirus protection regulations (Coronavirus-Schutzverordnungen).