scholarly journals Model-driven mitigation measures for reopening schools during the COVID-19 pandemic

2021 ◽  
Vol 118 (39) ◽  
pp. e2108909118
Author(s):  
Ryan Seamus McGee ◽  
Julian R. Homburger ◽  
Hannah E. Williams ◽  
Carl T. Bergstrom ◽  
Alicia Y. Zhou
Keyword(s):  
Social Interaction ◽  
Severe Acute Respiratory Syndrome ◽  
Secondary Schools ◽  
Protective Effect ◽  
Mitigation Measures ◽  
Stochastic Network ◽  
Model Driven ◽  
Interaction Control ◽  
Crucial Component ◽  
Reduce Risk

Reopening schools is an urgent priority as the COVID-19 pandemic drags on. To explore the risks associated with returning to in-person learning and the value of mitigation measures, we developed stochastic, network-based models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in primary and secondary schools. We find that a number of mitigation measures, alone or in concert, may reduce risk to acceptable levels. Student cohorting, in which students are divided into two separate populations that attend in-person classes on alternating schedules, can reduce both the likelihood and the size of outbreaks. Proactive testing of teachers and staff can help catch introductions early, before they spread widely through the school. In secondary schools, where the students are more susceptible to infection and have different patterns of social interaction, control is more difficult. Especially in these settings, planners should also consider testing students once or twice weekly. Vaccinating teachers and staff protects these individuals and may have a protective effect on students as well. Other mitigations, including mask wearing, social distancing, and increased ventilation, remain a crucial component of any reopening plan.

scholarly journals Model-driven mitigation measures for reopening schools during the COVID-19 pandemic

2021 ◽  
Author(s):  
Ryan S. McGee ◽  
Julian R. Homburger ◽  
Hannah E. Williams ◽  
Carl T. Bergstrom ◽  
Alicia Y. Zhou
Keyword(s):  
Social Interaction ◽  
Secondary Schools ◽  
Protective Effect ◽  
Mitigation Measures ◽  
Stochastic Network ◽  
Social Distancing ◽  
Model Driven ◽  
Interaction Control ◽  
Crucial Component ◽  
Reduce Risk

AbstractReopening schools is an urgent priority as the COVID-19 pandemic drags on. To explore the risks associated with returning to in-person learning and the value of mitigation measures, we developed stochastic, network-based models of SARS-CoV-2 transmission in primary and secondary schools. We find that a number of mitigation measures, alone or in concert, may reduce risk to acceptable levels particularly when community prevalence is low. Student cohorting, in which students are divided into two separate populations that attend in-person classes on alternating schedules, can reduce both the likelihood and the size of outbreaks. Proactive testing of teachers and staff once or twice a week can help catch introductions early, before they spread widely through the school. In secondary schools, where the students are more susceptible to infection and have different patterns of social interaction, control is more difficult. Especially in these settings, planners should also consider testing students once or twice weekly. Vaccinating teachers and staff protects these individuals and—when vaccines block SARS-CoV-2 transmission in addition to symptoms—may also have a protective effect on students as well. Other mitigations, including mask-wearing, social distancing, and increased ventilation, remain a crucial component of any reopening plan.

scholarly journals The Ugandan Severe Acute Respiratory Syndrome -Coronavirus 2 (SARS-CoV-2) Model: A Data Driven Approach to Estimate Risk

2021 ◽  
Author(s):  
Betty Nannyonga ◽  
Henry Kyobe Bosa ◽  
Yonas Tegegn Woldermariam ◽  
Pontiano Kaleebu ◽  
John M Ssenkusu ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Population Attributable Risk ◽  
Case Fatality ◽  
Truck Drivers ◽  
Mitigation Measures ◽  
Vulnerable Groups ◽  
Control Analysis ◽  
Age Group ◽  
Reproduction Ratio ◽  
First Case

AbstractObjectivesThe first case of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) was identified on March 21, 2020, in Uganda. The number of cases increased to 8,287 by September 30, 2020. By May throughout June, most of the cases were predominantly imported cases of truck drivers from neighbouring countries. Uganda responded with various restrictions and interventions including lockdown, physical distancing, hand hygiene, and use of face masks in public, to control the growth rate of the outbreak. By end of September 2020, Uganda had transitioned into community transmissions and most of the reported cases were locals contacts and alerts. This study assessed risks associated with SARS-CoV-2 in Uganda, and presents estimates of the reproduction ratio in real time. An optimal control analysis was performed to determine how long the current mitigation measures such as controlling the exposure in communities, rapid detection, confirmation and contact tracing, partial lockdown of the vulnerable groups and control at the porous boarders, could be implemented and at what cost.MethodsThe daily confirmed cases of SARS-CoV-2 in Uganda were extracted from publicly available sources. Using the data, relative risks for age, gender, and geographical location were determined. Four approaches were used to forecast SARS-CoV-2 in Uganda namely linear exponential, nonlinear exponential, logistic and a deterministic model. The discrete logistic model and the next generation matrix method were used to estimate the effective reproduction number.ResultsResults showed that women were at a higher risk of acquiring SARS-CoV-2 than the men, and the population attributable risk of SARS-CoV-2 to women was 42.22%. Most of the women affected by SARS-CoV-2 were likely contacts of cargo truck drivers at the boarders, where high infection rates were reported. Although most deaths in Uganda were in the age group of 60-69, the highest case fatality rate per 1000 was attributable the age group of 80-89, followed by 70-79. Geographically, Amuru had the highest relative risk compared to the national risk to SARS-CoV-2. For the case of mitigation scenarios, washing hands with 70% com pliance and regular hand washing of 6 times a day, was the most effective and sustainable to reduce SARS- CoV-2 exposure. This was followed by public wearing of face masks if at least 60% of the population complied, and physical distancing by 60% of the population. If schools, bars and churches were opened without compliance, i.e., no distancing, no handwashing and no public wearing of face masks, to mitigation measures, the highest incidence was observed, leading to a big replacement number. If mitigation measures are not followed by the population, then there will be high incidences and prevalence of the virus in the population.

scholarly journals Reducing travel-related SARS-CoV-2 transmission with layered mitigation measures: Symptom monitoring, quarantine, and testing

2020 ◽  
Author(s):  
Michael A. Johansson ◽  
Hannah Wolford ◽  
Prabasaj Paul ◽  
Pamela S. Diaz ◽  
Tai-Ho Chen ◽  
...  
Keyword(s):  
Transmission Risk ◽  
Mitigation Measures ◽  
Infectious Period ◽  
Time Of Arrival ◽  
Optimal Test ◽  
Symptom Monitoring ◽  
Trade Offs ◽  
Global Priority ◽  
Time Of Infection ◽  
Reduce Risk

AbstractBalancing the control of SARS-CoV-2 transmission with the resumption of travel is a global priority. Current recommendations include mitigation measures before, during, and after travel. Pre- and post-travel strategies including symptom monitoring, testing, and quarantine can be combined in multiple ways considering different trade-offs in feasibility, adherence, effectiveness, cost and adverse consequences. Here we use a mathematical model to analyze the expected effectiveness of symptom monitoring, testing, and quarantine under different estimates of the infectious period, test-positivity relative to time of infection, and test sensitivity to reduce the risk of transmission from infected travelers during and after travel. If infection occurs 0-7 days prior to travel, immediate isolation following symptom onset prior to or during travel reduces risk of transmission while traveling by 26-30%. Pre-departure testing can further reduce risk if testing is close to the time of departure. For example, testing on the day of departure can reduce risk while traveling by 37-61%. For transmission risk after travel with infection time up to 7 days prior to arrival at the destination, isolation based on symptom monitoring reduced introduction risk at the destination by 42-56%. A 14-day quarantine after arrival, without symptom monitoring or testing, can reduce risk by 97-100% on its own. However, a shorter quarantine of 7 days combined with symptom monitoring and a test on day 3-4 after arrival is also effective (95-99%) at reducing introduction risk and is less burdensome, which may improve adherence. To reduce the risk of introduction without quarantine, optimal test timing after arrival is close to the time of arrival; with effective quarantine after arrival, testing a few days later optimizes sensitivity to detect those infected immediately before or while traveling. These measures can complement recommendations such as social distancing, using masks, and hand hygiene, to further reduce risk during and after travel.

Development and Application of Risk-Based Inspection in Ethylene Compression Unit

2014 ◽  
Author(s):  
Jun Si ◽  
Yuqing Yang ◽  
Zhenrong Yan ◽  
Xiaoming Luo
Keyword(s):  
Failure Modes ◽  
Risk Mitigation ◽  
Pressure Vessels ◽  
Mitigation Measures ◽  
Mechanical Equipment ◽  
Process Industries ◽  
Static Mechanical ◽  
Inspection And Maintenance ◽  
Reduce Risk

Inspections are widely used in the process industries to reduce risk related to failure on static mechanical equipment. Risk-based inspection is one of effective tools to optimize inspection and maintenance planning. Based on principle of the risk-based inspection methodology, the main failure modes and damage mechanisms of pressure vessels and pipelines in ethylene compression unit are identified. The risk assessment of pressure vessels and pipelines is carried out. All pressure vessels and pipelines in this unit are prioritized based on the level of risk. Risk mitigation measures and optimal inspection and maintenance strategy are proposed. The results of risk evaluation have highlighted a clear improvement in the quality of inspection and maintenance of the ethylene compression unit.

scholarly journals Reducing travel-related SARS-CoV-2 transmission with layered mitigation measures: symptom monitoring, quarantine, and testing

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Michael A. Johansson ◽  
Hannah Wolford ◽  
Prabasaj Paul ◽  
Pamela S. Diaz ◽  
Tai-Ho Chen ◽  
...  
Keyword(s):  
Nucleic Acid Amplification ◽  
Transmission Risk ◽  
Mitigation Measures ◽  
Infectious Period ◽  
Optimal Test ◽  
Effective Measure ◽  
Symptom Monitoring ◽  
Test Sensitivity ◽  
Trade Offs ◽  
Reduce Risk

Abstract Background Balancing the control of SARS-CoV-2 transmission with the resumption of travel is a global priority. Current recommendations include mitigation measures before, during, and after travel. Pre- and post-travel strategies including symptom monitoring, antigen or nucleic acid amplification testing, and quarantine can be combined in multiple ways considering different trade-offs in feasibility, adherence, effectiveness, cost, and adverse consequences. Methods We used a mathematical model to analyze the expected effectiveness of symptom monitoring, testing, and quarantine under different estimates of the infectious period, test-positivity relative to time of infection, and test sensitivity to reduce the risk of transmission from infected travelers during and after travel. Results If infection occurs 0–7 days prior to travel, immediate isolation following symptom onset prior to or during travel reduces risk of transmission while traveling by 30–35%. Pre-departure testing can further reduce risk, with testing closer to the time of travel being optimal even if test sensitivity is lower than an earlier test. For example, testing on the day of departure can reduce risk while traveling by 44–72%. For transmission risk after travel with infection time up to 7 days prior to arrival at the destination, isolation based on symptom monitoring reduced introduction risk at the destination by 42–56%. A 14-day quarantine after arrival, without symptom monitoring or testing, can reduce post-travel risk by 96–100% on its own. However, a shorter quarantine of 7 days combined with symptom monitoring and a test on day 5–6 after arrival is also effective (97--100%) at reducing introduction risk and is less burdensome, which may improve adherence. Conclusions Quarantine is an effective measure to reduce SARS-CoV-2 transmission risk from travelers and can be enhanced by the addition of symptom monitoring and testing. Optimal test timing depends on the effectiveness of quarantine: with low adherence or no quarantine, optimal test timing is close to the time of arrival; with effective quarantine, testing a few days later optimizes sensitivity to detect those infected immediately before or while traveling. These measures can complement recommendations such as social distancing, using masks, and hand hygiene, to further reduce risk during and after travel.

scholarly journals Effectiveness of Face Masks in Preventing Airborne Transmission of SARS-CoV-2

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Hiroshi Ueki ◽  
Yuri Furusawa ◽  
Kiyoko Iwatsuki-Horimoto ◽  
Masaki Imai ◽  
Hiroki Kabata ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Protective Effect ◽  
Protective Efficiency ◽  
Airborne Transmission ◽  
Simulation Experiments ◽  
Additional Equipment ◽  
Human Respiration ◽  
Surgical Masks ◽  
And Performance

ABSTRACT Guidelines from the CDC and the WHO recommend the wearing of face masks to prevent the spread of coronavirus (CoV) disease 2019 (COVID-19); however, the protective efficiency of such masks against airborne transmission of infectious severe acute respiratory syndrome CoV-2 (SARS-CoV-2) droplets/aerosols is unknown. Here, we developed an airborne transmission simulator of infectious SARS-CoV-2-containing droplets/aerosols produced by human respiration and coughs and assessed the transmissibility of the infectious droplets/aerosols and the ability of various types of face masks to block the transmission. We found that cotton masks, surgical masks, and N95 masks all have a protective effect with respect to the transmission of infective droplets/aerosols of SARS-CoV-2 and that the protective efficiency was higher when masks were worn by a virus spreader. Importantly, medical masks (surgical masks and even N95 masks) were not able to completely block the transmission of virus droplets/aerosols even when completely sealed. Our data will help medical workers understand the proper use and performance of masks and determine whether they need additional equipment to protect themselves from infected patients. IMPORTANCE Airborne simulation experiments showed that cotton masks, surgical masks, and N95 masks provide some protection from the transmission of infective SARS-CoV-2 droplets/aerosols; however, medical masks (surgical masks and even N95 masks) could not completely block the transmission of virus droplets/aerosols even when sealed.

scholarly journals Assessing the impact of SARS-CoV-2 prevention measures in schools by means of agent-based simulations calibrated to cluster tracing data

2021 ◽  
Author(s):  
Jana Lasser ◽  
Johannes Sorger ◽  
Lukas Richter ◽  
Stefan Thurner ◽  
Daniela Schmid ◽  
...  
Keyword(s):  
Secondary Schools ◽  
Primary Schools ◽  
Cluster Size ◽  
Mitigation Measures ◽  
Necessary Condition ◽  
School Type ◽  
Strict Adherence ◽  
Agent Based ◽  
Source Case ◽  
The Impact

How to safely maintain schools open during a pandemic is still controversial. We aim to identify those measures that effectively control the spread of SARS-CoV-2 in schools. By control we mean that each source case infects less than one other person on average. Here, we analyze Austrian data on 616 clusters involving 2,822 student-cases and 676 teacher-cases with the aim to calibrate an agent-based epidemiological model in terms of cluster size and transmission risk depending on age and clinical presentation. With this model, we quantify the impact of preventive measures such as room ventilation, reduction of class size, wearing of masks during lessons, and school entry testing by SARS-CoV2-antigen tests. We find that 40% of all clusters involved no more than two cases, and 3% of the clusters only had more than 20 cases. The younger the students, the more likely we found asymptomatic cases and teachers as the source case of the in-school transmissions. Different school types require different combinations of measures to achieve control of the infection spreading: In primary schools, it is necessary to combine at least two of the aforementioned measures. In secondary schools, where contact networks of students and teachers become increasingly large and dense, a combination of three measures is needed. A sensitivity analysis indicated that the cluster size might increase up to three-fold in secondary schools for virus variants with an increased transmissibility by 50%, and that poorly executed or enforced mitigation measures might increase the cluster size by a factor of more than 30. Our results suggest that school-type-specific combinations of measures, when strictly adhered to, allow for a controlled opening of schools even under sustained community transmission of SARS-CoV-2. However, large clusters might still occur on an infrequent, however, regular basis. It is shown explicitly that strict adherence to the measures is a necessary condition for successful control.

scholarly journals Neural network of social interaction observation in marmosets

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Justine C Cléry ◽  
Yuki Hori ◽  
David J Schaeffer ◽  
Ravi S Menon ◽  
Stefan Everling
Keyword(s):  
Social Cognition ◽  
Social Interaction ◽  
Common Marmoset ◽  
Neural Basis ◽  
Primate Model ◽  
Old World ◽  
Crucial Component ◽  
The Social ◽  
The Common ◽  
The Brain

A crucial component of social cognition is to observe and understand the social interactions of other individuals. A promising nonhuman primate model for investigating the neural basis of social interaction observation is the common marmoset (Callithrix jacchus), a small New World primate that shares a rich social repertoire with humans. Here, we used functional magnetic resonance imaging acquired at 9.4 T to map the brain areas activated by social interaction observation in awake marmosets. We discovered a network of subcortical and cortical areas, predominately in the anterior lateral frontal and medial frontal cortex, that was specifically activated by social interaction observation. This network resembled that recently identified in Old World macaque monkeys. Our findings suggest that this network is largely conserved between New and Old World primates and support the use of marmosets for studying the neural basis of social cognition.

scholarly journals Testing Online Men’s Groups to Promote Psychological Well-Being and Reduce Despair During the COVID-19 Pandemic

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 526-527
Author(s):  
Paul Links ◽  
Sisira Sarma ◽  
Gordon Flett ◽  
Kimberly Wilson ◽  
Simon Hatcher ◽  
...  
Keyword(s):  
Public Health ◽  
Older Adults ◽  
Social Interaction ◽  
North America ◽  
Suicide Risk ◽  
Psychological Intervention ◽  
Well Being ◽  
Psychological Well Being ◽  
Online Delivery ◽  
Reduce Risk

Abstract Suicide prevention is a healthcare and social justice priority. Older adults have the highest rates of suicide and the highest COVID-19 fatality rates in North America. The combined impacts of social isolation, fear of infection, apathy, and hopelessness could amplify suicide risk among older adults, as appears to have been the case during the 2003 SARS epidemic in Hong Kong. Innovative interventions are thus needed to promote social interaction and reduce risk for suicide in these challenging times. We are currently testing an online version of our Meaning-Centered Men’s Group (MCMG; Heisel et al., 2020), an upstream psychological intervention designed to promote psychological well-being and reduce suicide risk among men struggling with the transition to retirement, in the context of pandemic-related public health restrictions. This presentation will focus on adaptations to MCMG for online delivery, and share participant experiences and findings on positive and negative psychological outcomes.

scholarly journals Understanding patterns of adherence to COVID-19 mitigation measures: a qualitative interview study

2021 ◽  
Author(s):  
Sarah Denford ◽  
Kate S Morton ◽  
Helen Lambert ◽  
Juan Zhang ◽  
Louise E Smith ◽  
...  
Keyword(s):  
Low Income ◽  
Population Level ◽  
Mitigation Measures ◽  
Structured Interviews ◽  
Topic Guide ◽  
Protective Measures ◽  
Qualitative Interview Study ◽  
Reduce Risk ◽  
Nuanced Understanding ◽  
Minority Ethnic

Abstract Background Evidence highlights the disproportionate impact of measures that have been introduced to reduce the spread of coronavirus on individuals from Black, Asian and minority ethnic (BAME) communities, and among those on a low income. An understanding of barriers to adherence in these populations is needed. In this qualitative study, we examined the patterns of adherence to mitigation measures and reasons underpinning these behaviors. Methods Semi-structured interviews were conducted with 20 participants from BAME and low-income White backgrounds. The topic guide was designed to explore how individuals are adhering to social distancing and self-isolation during the pandemic and to explore the reasons underpinning this behavior. Results We identified three categories of adherence to lockdown measures: (i) caution-motivated super-adherence (ii) risk-adapted partial-adherence and (iii) necessity-driven partial-adherence. Decisions about adherence considered potential for exposure to the virus, ability to reduce risk through use of protective measures and perceived importance of/need for the behavior. Conclusions This research highlights a need for a more nuanced understanding of adherence to lockdown measures. Provision of practical and financial support could reduce the number of people who have to engage in necessity-driven partial-adherence. More evidence is required on population level risks of people adopting risk-adapted partial-adherence.

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