scholarly journals Temporal Contact Graph Reveals the Evolving Epidemic Situation of COVID-19

2020 ◽  
Author(s):  
Mincheng Wu ◽  
Chao Li ◽  
Zhangchong Shen ◽  
Shibo He ◽  
Lingling Tang ◽  
...  
Keyword(s):  
User Involvement ◽  
Evaluation Framework ◽  
Control Measures ◽  
Contact Tracing ◽  
Contact Graph ◽  
Individual Level ◽  
Related Data ◽  
The United Kingdom ◽  
Pearson Coefficient ◽  
And Control

Abstract Contact tracing APPs have been recently advocated by many countries (e.g., the United Kingdom, Australia, etc.) as part of control measures on COVID-19. Controversies have been raised about their effectiveness in practice as it still remains unclear how they can be fully utilized to fuel the fight against COVID-19. In this article, we show that an abundance of information can be extracted from contact tracing for COVID-19 prevention and control, providing the first data-driven evidence that supports the wide implementation of such APPs. Specifically, we construct a temporal contact graph that quantifies the daily contacts between infectious and susceptible individuals by exploiting a large volume of location related data contributed by 10,527,737 smartphone users in Wuhan, China. Five time-varying indicators we introduce can accurately capture actual contact trends at individual and population levels, demonstrating that travel restriction in Wuhan played an important role in containing COVID-19. We reveal a strong correlation (Pearson coefficient 0.929) between daily confirmed cases and daily total contacts, which can be utilized as a new and efficient way to evaluate and predict the evolving epidemic situation of COVID-19. Further, we find that there is a prominent distinction of contact behaviors between the infected and uninfected contacted individuals, and design an infection risk evaluation framework to identify infected ones. This can help narrow down the search of high risk contacted individuals for quarantine. Our results indicate that user involvement has an explicit impact on individual-level contact trend estimation while minor impact on situation evaluation, offering guidelines for governments to implement contact tracing APPs.

scholarly journals Temporal Contact Graph Reveals The Evolving Epidemic Situation of COVID-19

2021 ◽  
Author(s):  
Mincheng Wu ◽  
Chao Li ◽  
Zhangchong Shen ◽  
Shibo He ◽  
Lingling Tang ◽  
...  
Keyword(s):  
Participation Rate ◽  
Population Level ◽  
User Participation ◽  
Contact Tracing ◽  
Prevention Measures ◽  
Contact Graph ◽  
Individual Level ◽  
Related Data ◽  
Epidemic Size ◽  
Travel Restrictions

Abstract Digital contact tracing has been recently advocated by China and many countries as part of digital prevention measures on COVID-19. Controversies have been raised about their effectiveness in practice as it remains open how they can be fully utilized to control COVID-19. In this article, we show that an abundance of information can be extracted from digital contact tracing for COVID-19 prevention and control. Specifically, we construct a temporal contact graph that quantifies the daily contacts between infectious and susceptible individuals by exploiting a large volume of location-related data contributed by 10,527,737 smartphone users in Wuhan, China. The temporal contact graph reveals five time-varying indicators can accurately capture actual contact trends at population level, demonstrating that travel restrictions (e.g., city lockdown) in Wuhan played an important role in containing COVID-19. We reveal a strong correlation between the contacts level and the epidemic size, and estimate several significant epidemiological parameters (e.g., serial interval). We also show that user participation rate exerts higher influence on situation evaluation than user upload rate does. At individual level, however, the temporal contact graph plays a limited role, since the behavior distinction between the infected and uninfected contacted individuals are not substantial. The revealed results can tell the effectiveness of digital contact tracing against COVID-19, providing guidelines for governments to implement interventions using information technology.

scholarly journals Containing the Spread of Coronavirus Disease 2019 (COVID-19): Meteorological Factors and Control Strategies

2020 ◽  
Author(s):  
Jun Lin ◽  
Weihao Huang ◽  
Muchen Wen ◽  
Shuyi Ma ◽  
Jiawen Hua ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Meteorological Factors ◽  
Control Strategies ◽  
Mainland China ◽  
Control Measures ◽  
Contact Tracing ◽  
Effect Of Temperature ◽  
Individual Level ◽  
Novel Coronavirus ◽  
And Control

AbstractThe novel coronavirus disease 2019 (COVID-19) has spread globally and the meteorological factors vary greatly across the world. Understanding the effect of meteorological factors and control strategies on COVID-19 transmission is critical to contain the epidemic. Using individual-level data in mainland China, Hong Kong, and Singapore, and the number of confirmed cases in other regions, we explore the effect of temperature, relative humidity, and control measures on the spread of COVID-19. We found that high temperature mitigates the transmission of the disease. High relative humidity promotes COVID-19 transmission when temperature is low, but tends to reduce transmission when temperature is high. Implementing classical control measures can dramatically slow the spread of the disease. However, due to the occurrence of pre-symptomatic infections, the effect of the measures to shorten onset-to-isolation time is markedly reduced and the importance of contact tracing and quarantine and social distancing increases. The analytic results also highlight the importance of early intervention to contain the spread of COVID-19.

An evaluation model of 2019-nCoV prevention effectiveness based on immigration data in China (Preprint)

2020 ◽  
Author(s):  
Qiangsheng Huang
Keyword(s):  
Prevention And Control ◽  
Time Window ◽  
Evaluation Model ◽  
Control Measures ◽  
Related Data ◽  
The Face ◽  
Prevention And Control Measures ◽  
And Control ◽  
Best Fit

BACKGROUND As of the end of February 2020, 2019-nCoV is currently well controlled in China. However, the virus is now spreading globally. OBJECTIVE This study aimed to evaluate the effectiveness of outbreak prevention and control measures in a region. METHODS A model is built for find the best fit for two sets of data (the number of daily new diagnosed, and the risk value of incoming immigration population). The parameters (offset and time window) in the model can be used as the evaluation of effectiveness of outbreak prevention and control. RESULTS Through study, it is found that the parameter offset and time window in the model can accurately reflect the prevention effectiveness. Some related data and public news confirm this result. And this method has advantages over the method using R0 in two aspects. CONCLUSIONS If the epidemic situation is well controlled, the virus is not terrible. Now the daily new diagnosed patients in most regions of China is quickly reduced to zero or close to zero. Chinese can do a good job in the face of huge epidemic pressure. Therefore, if other countries can do well in prevention and control, the epidemic in those places can also pass quickly.

scholarly journals COVID-19 prevention and control measures in workplace settings: a rapid review and meta-analysis

2021 ◽  
Author(s):  
Carolyn Ingram ◽  
Vicky Downey ◽  
Mark Roe ◽  
Fionn Cléirigh Büttner ◽  
Yanbing Chen ◽  
...  
Keyword(s):  
High Risk ◽  
Prevention And Control ◽  
Meta Analysis ◽  
Control Measures ◽  
Contact Tracing ◽  
Rapid Review ◽  
Cochrane Library ◽  
Infection Prevention And Control ◽  
Post Intervention ◽  
And Control

Workplaces are high-risk environments for SARS-CoV-2 outbreaks and subsequent community transmission. Identifying, understanding, and implementing effective workplace SARS-CoV-2 infection prevention and control (IPC) measures is critical to protect workers, their families, and communities. A rapid review and meta-analysis were conducted to synthesize evidence assessing the effectiveness of COVID-19 IPC measures implemented in global workplace settings through April 2021. Medline, Embase, PubMed, and Cochrane Library were searched for studies that quantitatively assessed the effectiveness of workplace COVID-19 IPC measures. Included studies comprised varying empirical designs and occupational settings. Measures of interest included surveillance measures, outbreak investigations, personal protective equipment (PPE), changes in work arrangements, and worker education. Sixty-three studies from international healthcare, nursing home, meatpacking, manufacturing, and office settings were included, accounting for ~280,000 employees. Meta-analyses showed that combined measures (0.2% positivity; 95%CI 0-0.4%) were associated with lower post-intervention employee COVID-19 positivity estimates than single measures like asymptomatic PCR testing (1.7%; 95%CI 0.9-2.9%) and universal masking (24%; 95%CI 3.4-55.5%). Modelling studies showed that combinations of (i) timely and widespread contact tracing and case isolation, (ii) facilitating smaller worker cohorts, and (iii) effective use of PPE can reduce workplace transmission. Comprehensive COVID-19 IPC measures incorporating swift contact tracing and case isolation, PPE, and facility zoning, can effectively prevent workplace outbreaks. Masking alone should not be considered as sufficient protection from SARS-CoV-2 outbreaks in workplace environments at high risk of virus transmission.

scholarly journals Estimating the Impact of Control Measures to Prevent Outbreaks of COVID-19 Associated with Air Travel into a COVID-19-free country: A Simulation Modelling Study

2020 ◽  
Author(s):  
Nick Wilson ◽  
Michael G Baker ◽  
Martin Eichner
Keyword(s):  
Simulation Modelling ◽  
Air Travel ◽  
Control Measures ◽  
Contact Tracing ◽  
Uncertainty Interval ◽  
Policy Makers ◽  
Stochastic Version ◽  
Low Prevalence ◽  
And Control ◽  
The Impact

AbstractAimsWe aimed to estimate the risk of COVID-19 outbreaks associated with air travel from a country with a very low prevalence of COVID-19 infection (Australia) to a COVID-19-free country (New Zealand; [NZ]), along with the likely impact of various control measures for passengers and cabin crew.MethodsA stochastic version of the SEIR model CovidSIM v1.1, designed specifically for COVID-19 was utilized. It was populated with data for both countries and parameters for SARS-CoV-2 transmission and control measures. We assumed one Australia to NZ flight per day.ResultsWhen no interventions were in place, an outbreak of COVID-19 in NZ was estimated to occur after an average time of 1.7 years (95% uncertainty interval [UI]: 0.04-6.09). However, the combined use of exit and entry screening (symptom questionnaire and thermal camera), masks on aircraft and two PCR tests (on days 3 and 12 in NZ), combined with self-reporting of symptoms and contact tracing and mask use until the second PCR test, reduced this risk to one outbreak every 29.8 years (0.8 to 110). If no PCR testing was performed, but mask use was used by passengers up to day 15 in NZ, the risk was one outbreak every 14.1 years. However, 14 days quarantine (NZ practice in May 2020), was the most effective strategy at one outbreak every 34.1 years (0.06 to 125); albeit combined with exit screening and mask use on flights.ConclusionsPolicy-makers can require multi-layered interventions to markedly reduce the risk of importing the pandemic virus into a COVID-19-free nation via air travel. There is potential to replace 14-day quarantine with PCR testing or interventions involving mask use by passengers in NZ. However, all approaches require continuous careful management and evaluation.

An evaluation model of 2019-nCoV prevention and control effectiveness based on immigration data in China (Preprint)

2020 ◽  
Author(s):  
Qiangsheng Huang
Keyword(s):  
Prevention And Control ◽  
Evaluation Model ◽  
Control Measures ◽  
Related Data ◽  
Control Effectiveness ◽  
The Face ◽  
Prevention And Control Measures ◽  
And Control ◽  
Best Fit

BACKGROUND As of the end of February 2020, 2019-nCoV is currently well controlled in China. However, the virus is now spreading globally. OBJECTIVE This study aimed to evaluate the effectiveness of outbreak prevention and control measures in a region. METHODS A model is built for find the best fit for two sets of data (the number of daily new diagnosed, and the risk value of incoming immigration population). The parameters (offset and window) in the model can be used as the evaluation of effectiveness of outbreak prevention and control. RESULTS Through study, it is found that the parameter offset and window in the model can accurately reflect the prevention effectiveness. Some related data and public news confirm this result. And this method has advantages over the method using R0 in two aspects. CONCLUSIONS If the epidemic situation is well controlled, the virus is not terrible. Now the daily new diagnosed patients in most regions of China is quickly reduced to zero or close to zero. Chinese can do a good job in the face of huge epidemic pressure. Therefore, if other countries can do well in prevention and control, the epidemic in those places can also pass quickly.

scholarly journals The first community outbreak of COVID-19 in Viet Nam: description and lessons learned

2021 ◽  
Vol 12 (2) ◽  
pp. 42-50
Author(s):  
Duong Nhu Tran ◽  
Quynh Mai Thi Le ◽  
Hien Tran Nguyen ◽  
Nghia Duy Ngu ◽  
Khoa Trong Nguyen ◽  
...  
Keyword(s):  
Preventive Measures ◽  
Clinical Symptoms ◽  
Lessons Learned ◽  
Control Measures ◽  
Contact Tracing ◽  
Viet Nam ◽  
Prevention And Control Measures ◽  
Novel Coronavirus ◽  
Nonpharmaceutical Interventions ◽  
And Control

Objective: At the time of this study, the prevention of novel coronavirus disease 2019 (COVID-19) relied solely on nonpharmaceutical interventions. Implementation of these interventions is not always optimal and, consequently, several cases were imported into non-epidemic areas and led to large community outbreaks. This report describes the characteristics of the first community outbreak of COVID-19 in Viet Nam and the intensive preventive measures taken in response. Methods: Cases were detected and tested for SARS-CoV-2 by real-time reverse transcriptase polymerase chain reaction. Contact tracing and active surveillance were conducted to identify suspected cases and individuals at risk. Clinical symptoms were recorded using a standardized questionnaire. Results: In Vinh Phuc province from 20 January to 3 March 2020, there were 11 confirmed cases among 158 suspected cases and 663 contacts. Nine of the confirmed cases (81.8%) had mild symptoms at the time of detection and two (18.2%) were asymptomatic; none required admission to an intensive care unit. Five prevention and control measures were implemented, including quarantining a community of 10 645 individuals for 20 days. The outbreak was successfully contained as of 13 February 2020. Discussion: In the absence of specific interventions, the intensive use of combined preventive measures can mitigate the spread of COVID-19. The lessons learned may be useful for other communities.

scholarly journals Traffic control and social distancing evidence from COVID-19 in China

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252300
Author(s):  
Shanlang Lin ◽  
Ruofei Lin ◽  
Na Yan ◽  
Junpei Huang
Keyword(s):  
Traffic Control ◽  
Prevention And Control ◽  
Mainland China ◽  
Control Measures ◽  
Epidemic Control ◽  
Social Distancing ◽  
Related Data ◽  
Risk Areas ◽  
Two Measures ◽  
And Control

We collected COVID-19 epidemiological and epidemic control measures-related data in mainland China during the period January 1 to February 19, 2020, and empirically tested the practical effects of the epidemic control measures implemented in China by applying the econometrics approach. The results show that nationally, both traffic control and social distancing have played an important role in controlling the outbreak of the epidemic, however, neither of the two measures have had a significant effect in low-risk areas. Moreover, the effect of traffic control is more successful than that of social distancing. Both measures complement each other, and their combined effect achieves even better results. These findings confirm the effectiveness of the measures currently in place in China, however, we would like to emphasize that control measures should be more tailored, which implemented according to each specific city’s situation, in order to achieve a better epidemic prevention and control.

scholarly journals Challenges of investigating a large food-borne norovirus outbreak across all branches of a restaurant group in the United Kingdom, October 2016

2019 ◽  
Vol 24 (18) ◽  
Author(s):  
Mari Morgan ◽  
Vicky Watts ◽  
David Allen ◽  
Daniele Curtis ◽  
Amir Kirolos ◽  
...  
Keyword(s):  
United Kingdom ◽  
Control Measures ◽  
The European Union ◽  
Preparation Methods ◽  
Public Health Agencies ◽  
The United Kingdom ◽  
Analytical Studies ◽  
Food Borne ◽  
Retrospective Cohort Studies ◽  
And Control

During October and November 2016, over 1,000 customers and staff reported gastroenteritis after eating at all 23 branches of a restaurant group in the United Kingdom. The outbreak coincided with a new menu launch and norovirus was identified as the causative agent. We conducted four retrospective cohort studies; one among all restaurant staff and three in customers at four branches. We investigated the dishes consumed, reviewed recipes, interviewed chefs and inspected restaurants to identify common ingredients and preparation methods for implicated dishes. Investigations were complicated by three public health agencies concurrently conducting multiple analytical studies, the complex menu with many shared constituent ingredients and the high media attention. The likely source was a contaminated batch of a nationally distributed ingredient, but analytical studies were unable to implicate a single ingredient. The most likely vehicle was a new chipotle chilli product imported from outside the European Union, that was used uncooked in the implicated dishes. This outbreak exemplifies the possibility of rapid spread of infectious agents within a restaurant supply chain, following introduction of a contaminated ingredient. It underlines the importance of appropriate risk assessments and control measures being in place, particularly for new ingredients and ready-to-eat foods.

scholarly journals Latest Effective Measures to Combat COVID-19: A Review

2021 ◽  
Author(s):  
Fei Chen ◽  
Yingjie Liu ◽  
Bailiu Ya ◽  
Jiarui He ◽  
Taiyang Leng ◽  
...  
Keyword(s):  
Control Measures ◽  
Cold Chain ◽  
Contact Tracing ◽  
Repeated Testing ◽  
Pandemic Preparedness ◽  
Susceptible Population ◽  
Source Of Infection ◽  
Prevention And Control Measures ◽  
State Interventions ◽  
And Control

More and more people realize that implementation of preventive measures is the only option left to counteract the coronavirus disease 2019 (COVID-19) before specific antiviral drugs are developed. Hence, a number of behavioral, clinical and state interventions have been conducted by dozens of countries to stop or slow down the spread of the virus in the early stages of the epidemic. At present, with the evolution of COVID-19 pandemic getting worse, synthesizing and implementing all measures available are of paramount importance. However, some measures are still being controversial. We aimed to assist policymakers in decision making for better pandemic preparedness. We reviewed the literature that reported accumulated scientific experience to date and summarized the epidemic prevention and control measures in three aspects: control the source of infection, cut off the routes of transmission and protect the susceptible population. First of all, some new approaches were introduced to control the source of infection, such as implementing contact-tracing apps, nucleic acid mixed detection, repeated testing and the establishment of some specialized laboratories. Second, we need to take various measures to cut off all possible routes of transmission, especially persistently pay close attention to checking cold chain foods. Third, due to no valid vaccine has yet been developed, some measures that can cut development time of more conventional vaccines should be implemented or considered. By synthesizing the scientific experience in fighting the COVID-19 epidemic, we suggested the latest effective measures should be carried out concurrently from three aspects, so as to avoid making grim situation even worse.

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