scholarly journals Face Masks Against COVID-19: An Evidence Review

2020 ◽  
Author(s):  
Jeremy Howard ◽  
Austin Huang ◽  
Zhiyuan Li ◽  
Zeynep Tufekci ◽  
Vladimir Zdimal ◽  
...  
Keyword(s):  
Relevant Literature ◽  
Transmission Probability ◽  
Disease Spread ◽  
Contact Tracing ◽  
Source Control ◽  
Public Officials ◽  
Effective Form ◽  
Route Of Transmission ◽  
Asymptomatic Individuals ◽  
The Cost

The science around the use of masks by the general public to impede COVID-19 transmission is advancing rapidly. Policymakers need guidance on how masks should be used by the general population to combat the COVID-19 pandemic. Here, we synthesize the relevant literature to inform multiple areas: 1) transmission characteristics of COVID-19, 2) filtering characteristics and efficacy of masks, 3) estimated population impacts of widespread community mask use, and 4) sociological considerations for policies concerning mask-wearing. A primary route of transmission of COVID-19 is likely via small respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals. Reducing disease spread requires two things: first, limit contacts of infected individuals via physical distancing and contact tracing with appropriate quarantine, and second, reduce the transmission probability per contact by wearing masks in public, among other measures. The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at stopping spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Thus we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

scholarly journals Face Masks Against COVID-19: An Evidence Review

2020 ◽  
Author(s):  
Jeremy Howard ◽  
Austin Huang ◽  
Zhiyuan Li ◽  
Zeynep Tufekci ◽  
Vladimir Zdimal ◽  
...  
Keyword(s):  
Relevant Literature ◽  
Population Level ◽  
Transmission Probability ◽  
Analytical Framework ◽  
Disease Spread ◽  
Contact Tracing ◽  
Source Control ◽  
Individual Outcomes ◽  
Route Of Transmission ◽  
Asymptomatic Individuals

The science around the use of masks by the general public to impede COVID-19 transmission is advancing rapidly. Policymakers need guidance on how masks should be used by the general population to combat the COVID-19 pandemic. Here,we develop an analytical framework to examine an overlooked aspect of mask usage: masks as source-control targeting egress from the wearer with benefits at the population-level, rather than as PPE used for ingress control for health-care workers with focus on individual outcomes. We consider and synthesize the relevant literature to inform multiple areas: 1) transmission characteristics of COVID-19, 2) filtering characteristics and efficacy of masks, 3) estimated population impacts of widespread community mask use, and 4) sociological considerations for policies concerning mask-wearing. A primary route of transmission of COVID-19 is likely via respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals. Reducing disease spread requires two things: first, limit contacts of infected individuals via physical distancing and other measures, and second, reduce the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Given the current shortages of medical masks we recommend the adoption of public cloth mask wearing, as an effective form of source control for now, in conjunction with existing hygiene, distancing, and contact tracing strategies. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

scholarly journals An evidence review of face masks against COVID-19

2021 ◽  
Vol 118 (4) ◽  
pp. e2014564118 ◽  
Author(s):  
Jeremy Howard ◽  
Austin Huang ◽  
Zhiyuan Li ◽  
Zeynep Tufekci ◽  
Vladimir Zdimal ◽  
...  
Keyword(s):  
Relevant Literature ◽  
Population Level ◽  
Transmission Probability ◽  
Analytical Framework ◽  
Disease Spread ◽  
Contact Tracing ◽  
Source Control ◽  
Individual Outcomes ◽  
Route Of Transmission ◽  
Asymptomatic Individuals

The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people (“source control”) with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

scholarly journals Face Masks Against COVID-19: An Evidence Review

2020 ◽  
Author(s):  
Jeremy Howard ◽  
Austin Huang ◽  
Zhiyuan Li ◽  
Zeynep Tufekci ◽  
Vladimir Zdimal ◽  
...  
Keyword(s):  
Relevant Literature ◽  
Population Level ◽  
Transmission Probability ◽  
Analytical Framework ◽  
Disease Spread ◽  
Contact Tracing ◽  
Source Control ◽  
Individual Outcomes ◽  
Route Of Transmission ◽  
Respiratory Droplets

The science around the use of masks by the general public to impede COVID-19 transmission is advancing rapidly. Policymakers need guidance on how masks should be used by the general population to combat the COVID-19 pandemic. In this narrative review, we develop an analytical framework to examine mask usage, considering and synthesizing the relevant literature to inform multiple areas: population impact; transmission characteristics; source control; PPE; sociological considerations; and implementation considerations. A primary route of transmission of COVID-19 is via respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals. Reducing disease spread requires two things: first, limit contacts of infected individuals via physical distancing and other measures, and second, reduce the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Given the current shortages of medical masks we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory droplets become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask-wearing by infectious people ("source control") with benefits at the population-level, rather than mask-wearing by susceptible people, such as health-care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

scholarly journals Face Masks Against COVID-19: An Evidence Review

2020 ◽  
Author(s):  
Jeremy Howard ◽  
Austin Huang ◽  
Zhiyuan Li ◽  
Zeynep Tufekci ◽  
Vladimir Zdimal ◽  
...  
Keyword(s):  
Relevant Literature ◽  
Population Level ◽  
Transmission Probability ◽  
Analytical Framework ◽  
Disease Spread ◽  
Contact Tracing ◽  
Source Control ◽  
Individual Outcomes ◽  
Route Of Transmission ◽  
Respiratory Droplets

The science around the use of masks by the general public to impede COVID-19 transmission is advancing rapidly. Policymakers need guidance on how masks should be used by the general population to combat the COVID-19 pandemic. In this narrative review, we develop an analytical framework to examine mask usage, considering and synthesizing the relevant literature to inform multiple areas: population impact; transmission characteristics; source control; PPE; sociological considerations; and implementation considerations. A primary route of transmission of COVID-19 is via respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals. Reducing disease spread requires two things: first, limit contacts of infected individuals via physical distancing and other measures, and second, reduce the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Given the current shortages of medical masks we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory droplets become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask-wearing by infectious people ("source control") with benefits at the population-level, rather than mask-wearing by susceptible people, such as health-care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

EPIDEMIOLOGIC PROFILE OF THE INITIAL COVID 19 PATIENTS AT A DESIGNATED COVID HOSPITAL IN SOUTH TAMIL NADU

2021 ◽  
pp. 73-75
Author(s):  
John, Jebamalar ◽  
Manohar, Madhumitha ◽  
Kumaraswamy Uma Suresh Balan
Keyword(s):  
Tamil Nadu ◽  
Respiratory Illness ◽  
Transmission Probability ◽  
Asymptomatic Infection ◽  
Disease Spread ◽  
Contact Tracing ◽  
Surveillance Systems ◽  
Travel History ◽  
Epidemiologic Profile ◽  
Positive Contact

BACKGROUND:COVID-19, caused by SARS CoV-2 has caused a worldwide pandemic since its origins in December 2019. The spectrum of the disease ranges from asymptomatic infection to severe respiratory illness causing mortality in severe cases. Person to person spread through respiratory droplets appears to be the most common route of spread. AIM & OBJECTIVE:This study aims to assess the demographic prole of COVID-19 patients. In addition, measures of transmission probability are determined using travel history and contact tracing. SETTINGS AND DESIGN: This study was done at a Government medical college in South Tamil Nadu over four months among patients who were RT-PCR positive for SARS CoV-2. METHODS AND MATERIAL: Aquestionnaire from NCDC for COVID-19 patients was used for collecting demographic and clinical details. Travel history and contact tracing were obtained using telephonic interviews and in person interviews. STATISTICALANALYSIS USED: Data was entered using MS-Excel and analysed using R studio version 3.6.3. RESULTS: Majority of the patients belonged to 20 to 49 years of age. Around 14.6% were symptomatic with fever and sore throat being predominant. Diabetes and hypertension were the most associated comorbidities. A positive contact history was present among 46.58% of the cases. The secondary attack rate was 25.03% and R0 was 2.76 CONCLUSIONS: The absence of a positive contact history and the preponderance of asymptomatic cases seem to contribute to the spread of the disease and impede control efforts. Hence, a multi-pronged approach including community participation, active surveillance systems and legal measures would be of great impact in slowing disease spread.

Stroke Prevention in Non-Valvular Atrial Fibrillation

1997 ◽  
Vol 17 (03) ◽  
pp. 166-169
Author(s):  
Judith O’Brien ◽  
Wendy Klittich ◽  
J. Jaime Caro
Keyword(s):  
Atrial Fibrillation ◽  
Clinical Trials ◽  
Care Home ◽  
Relevant Literature ◽  
Clinical Trial Data ◽  
Outcome Data ◽  
Sensitivity Analyses ◽  
Bleeding Events ◽  
Discharge Data ◽  
The Cost

SummaryDespite evidence from 6 major clinical trials that warfarin effectively prevents strokes in atrial fibrillation, clinicians and health care managers may remain reluctant to support anticoagulant prophylaxis because of its perceived costs. Yet, doing nothing also has a price. To assess this, we carried out a pharmacoe-conomic analysis of warfarin use in atrial fibrillation. The course of the disease, including the occurrence of cerebral and systemic emboli, intracranial and other major bleeding events, was modeled and a meta-analysis of the clinical trials and other relevant literature was carried out to estimate the required probabilities with and without warfarin use. The cost of managing each event, including acute and subsequent care, home care equipment and MD costs, was derived by estimating the cost per resource unit, the proportion consuming each resource and the volume of use. Unit costs and volumes of use were determined from established US government databases, all charges were adjusted using cost-to-charge ratios, and a 3% discount rate was applied to costs incurred beyond the first year. The proportions of patients consuming each resource were estimated by fitting a joint distribution to the clinical trial data, stroke outcome data from a recent Swedish study and aggregate ICD-9 specific, Massachusetts discharge data. If nothing is done, 3.2% more patients will suffer serious emboli annually and the expected annual cost of managing a patient will increase by DM 2,544 (1996 German Marks), from DM 4,366 to DM 6,910. Extensive multiway sensitivity analyses revealed that the higher price of doing nothing persists except for very extreme combinations of inputs unsupported by literature or clinical standards. The price of doing nothing is thus so high, both in health and economic terms, that cost-consciousness as well as clinical considerations mandate warfarin prophylaxis in atrial fibrillation.

scholarly journals How detection ranges and usage stops impact digital contact tracing effectiveness for COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Konstantin D. Pandl ◽  
Scott Thiebes ◽  
Manuel Schmidt-Kraepelin ◽  
Ali Sunyaev
Keyword(s):  
Disease Spread ◽  
Contact Tracing ◽  
Behavioral Characteristics ◽  
Policy Makers ◽  
Detection Range ◽  
Proximity Detection ◽  
Effective Technology ◽  
Different Types ◽  
Effectiveness And Efficiency ◽  
The Impact

AbstractTo combat the COVID-19 pandemic, many countries around the globe have adopted digital contact tracing apps. Various technologies exist to trace contacts that are potentially prone to different types of tracing errors. Here, we study the impact of different proximity detection ranges on the effectiveness and efficiency of digital contact tracing apps. Furthermore, we study a usage stop effect induced by a false positive quarantine. Our results reveal that policy makers should adjust digital contact tracing apps to the behavioral characteristics of a society. Based on this, the proximity detection range should at least cover the range of a disease spread, and be much wider in certain cases. The widely used Bluetooth Low Energy protocol may not necessarily be the most effective technology for contact tracing.

scholarly journals Relative infectiousness of asymptomatic SARS-CoV-2 infected persons compared with symptomatic individuals: a rapid scoping review

BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e042354
Author(s):  
David McEvoy ◽  
Conor McAloon ◽  
Aine Collins ◽  
Kevin Hunt ◽  
Francis Butler ◽  
...  
Keyword(s):  
Scoping Review ◽  
Quantitative Measure ◽  
Contact Tracing ◽  
Cochrane Library ◽  
International Studies ◽  
Screening Process ◽  
Modelling Studies ◽  
Asymptomatic Individuals ◽  
Definition Of ◽  
The Cochrane Library

ObjectivesThe aim of this study was to determine the relative infectiousness of asymptomatic SARS-CoV-2 infected persons compared with symptomatic individuals based on a scoping review of available literature.DesignRapid scoping review of peer-reviewed literature from 1 January to 5 December 2020 using the LitCovid database and the Cochrane library.SettingInternational studies on the infectiousness of individuals infected with SARS-CoV-2.ParticipantsStudies were selected for inclusion if they defined asymptomatics as a separate cohort distinct from presymptomatics and if they provided a quantitative measure of the infectiousness of asymptomatics relative to symptomatics.Primary outcome measuresPCR result (PCR studies), the rate of infection (mathematical modelling studies) and secondary attack rate (contact tracing studies) - in each case from asymptomatic in comparison with symptomatic individuals.ResultsThere are only a limited number of published studies that report estimates of relative infectiousness of asymptomatic compared with symptomatic individuals. 12 studies were included after the screening process. Significant differences exist in the definition of infectiousness. PCR studies in general show no difference in shedding levels between symptomatic and asymptomatic individuals; however, the number of study subjects is generally limited. Two modelling studies estimate relative infectiousness to be 0.43 and 0.57, but both of these were more reflective of the infectiousness of undocumented rather than asymptomatic cases. The results from contact tracing studies include estimates of relative infectiousness of 0, but with insufficient evidence to conclude that it is significantly different from 1.ConclusionsThere is considerable heterogeneity in estimates of relative infectiousness highlighting the need for further investigation of this important parameter. It is not possible to provide any conclusive estimate of relative infectiousness, as the estimates from the reviewed studies varied between 0 and 1.

Measuring the air pollution cost of shale gas development in China

2019 ◽  
Vol 31 (6) ◽  
pp. 1098-1111
Author(s):  
Zhengwei Ma ◽  
Yuanjun Pang ◽  
Dan Zhang ◽  
Yuqi Zhang
Keyword(s):  
Air Pollution ◽  
Shale Gas ◽  
Social Cost ◽  
Relevant Literature ◽  
Measurement Model ◽  
The United States ◽  
Recoverable Reserves ◽  
The Cost ◽  
Gas Fields ◽  
Ecological Cost

Shale gas is one of the most promising unconventional hydrocarbon resources in the 21st century. In recent years, economically recoverable reserves have achieved explosive growth, and drilling techniques have made large breakthroughs. As a clean unconventional energy, shale gas is given substantial consideration by governments. However, the cleanliness of shale gas has been questioned for causing serious air pollution during production. To further measure the air pollution cost during the exploration and transportation of shale gas, this article establishes an economic measurement model of the air pollution cost from the three aspects of human health, social cost and ecological cost by reviewing the relevant literature in the United States and China. This study lays a foundation for further calculating the cost of air pollution around shale gas fields.

scholarly journals Model Penyebaran Penyakit SIR Tipe Rantai Binomial dengan Kontak Random dan Waktu Penyembuhan Bernilai Tak Hingga

2021 ◽  
Vol 3 (2) ◽  
pp. 132
Author(s):  
Ilham Asyifa Maulana Rosyid ◽  
Respatiwulan Respatiwulan ◽  
Sri Sulistijowati Handajani
Keyword(s):  
Epidemic Model ◽  
Recovery Time ◽  
Transition Probability ◽  
Transmission Probability ◽  
Disease Spread ◽  
Sir Epidemic Model ◽  
Sir Epidemic ◽  
Long Life ◽  
Number Of Individuals ◽  
Chain Type

<p>Susceptible-Infected-Recovered (SIR) epidemic model is an epidemic model that illustrates the pattern of disease spread with the characteristics of individuals who have recovered cannot be re-infected and have a permanent immune system. The binomial chain type epidemic model assumes that infection spreads in discrete time units and the number of the infected individuals follows a binomial distribution. This research aims to discuss  binomial chain type SIR epidemic model by simulating the model. The transition probability depends on  the number of infected individuals in the period   the number of individuals encountered, and  the transmission probability. This model also assumes an infinite recovery time ( = ∞). This situation illustrates that infected individuals remain contagious during the period of spread of the disease. This situation can arise when the causative agent of the disease has a long life. Then simulations are performed by giving different transmission probability  The results show that the greater transmission probability will cause the probability of a new individual being infected in the next period to be greater.</p><p><strong>Keywords</strong><strong> : </strong>SIR<em> </em>epidemic model, binomial chain, infinite recovery time</p>

Sign in / Sign up

Export Citation Format

Share Document