scholarly journals Evaluating the Effectiveness of COVID-19 Bluetooth-Based Smartphone Contact Tracing Applications

2020 ◽  
Vol 10 (20) ◽  
pp. 7113 ◽  
Author(s):  
Enrique Hernández-Orallo ◽  
Carlos T. Calafate ◽  
Juan-Carlos Cano ◽  
Pietro Manzoni
Keyword(s):  
Infectious Diseases ◽  
Epidemic Model ◽  
Contact Tracing ◽  
Reproductive Number ◽  
Smartphone Applications ◽  
Social Distancing ◽  
Implementation Model ◽  
Decentralized Model ◽  
Centralized Model

One of the strategies to control the spread of infectious diseases is based on the use of specialized applications for smartphones. These apps offer the possibility, once individuals are detected to be infected, to trace their previous contacts in order to test and detect new possibly-infected individuals. This paper evaluates the effectiveness of recently developed contact tracing smartphone applications for COVID-19 that rely on Bluetooth to detect contacts. We study how these applications work in order to model the main aspects that can affect their performance: precision, utilization, tracing speed and implementation model (centralized vs. decentralized). Then, we propose an epidemic model to evaluate their efficiency in terms of controlling future outbreaks and the effort required (e.g., individuals quarantined). Our results show that smartphone contact tracing can only be effective when combined with other mild measures that can slightly reduce the reproductive number R0 (for example, social distancing). Furthermore, we have found that a centralized model is much more effective, requiring an application utilization percentage of about 50% to control an outbreak. On the contrary, a decentralized model would require a higher utilization to be effective.

SIV EPIDEMIC MODELS WITH AGE OF INFECTION

2009 ◽  
Vol 02 (01) ◽  
pp. 61-67 ◽  
Author(s):  
JUN-YUAN YANG ◽  
FENG-QIN ZHANG ◽  
XIAO-YAN WANG
Keyword(s):  
Integral Equation ◽  
Infectious Diseases ◽  
Epidemic Model ◽  
Endemic Equilibrium ◽  
Epidemic Models ◽  
Reproductive Number ◽  
Asymptotically Stable ◽  
Age Of Infection

accination is a very important strategy for the elimination of infectious diseases. An SIV epidemic model with age of infection and vaccination has been formulated in this paper. Using the theory of differential and integral equation, we show that the infection-free equilibrium is locally asymptotically stable if the reproductive number R0 < 1, and the endemic equilibrium is locally asymptotically stable if R0 > 1.

scholarly journals State-level impact of social distancing and testing on COVID-19 in the United States

2020 ◽  
Author(s):  
Weihsueh A. Chiu ◽  
Rebecca Fischer ◽  
Martial L. Ndeffo-Mbah
Keyword(s):  
United States ◽  
Large Scale ◽  
Disease Incidence ◽  
State Level ◽  
The United States ◽  
Contact Tracing ◽  
Reproductive Number ◽  
Social Distancing ◽  
Epidemic Curve ◽  
The Impact

Abstract Social distancing measures have been implemented in the United States (US) since March 2020, to mitigate the spread of SARS-CoV-2, the causative agent of COVID-19. However, by mid-May most states began relaxing these measures to support the resumption of economic activity, even as disease incidence continued to increase in many states. To evaluate the impact of relaxing social distancing restrictions on COVID-19 dynamics and control in the US, we developed a transmission dynamic model and calibrated it to US state-level COVID-19 cases and deaths from March to June 20th, 2020, using Bayesian methods. We used this model to evaluate the impact of reopening, social distancing, testing, contact tracing, and case isolation on the COVID-19 epidemic in each state. We found that using stay-at-home orders, most states were able to curtail their COVID-19 epidemic curve by reducing and achieving an effective reproductive number below 1. But by June 20th, 2020, only 19 states and the District of Columbia were on track to curtail their epidemic curve with a 75% confidence, at current levels of reopening. Of the remaining 31 states, 24 may have to double their current testing and/or contact tracing rate to curtail their epidemic curve, and seven need to further restrict social contact by 25% in addition to doubling their testing and contact tracing rates. When social distancing restrictions are being eased, greater state-level testing and contact tracing capacity remains paramount for mitigating the risk of large-scale increases in cases and deaths.

scholarly journals Transmission dynamics and control of two epidemic waves of SARS-CoV-2 in South Korea

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sukhyun Ryu ◽  
Sheikh Taslim Ali ◽  
Eunbi Noh ◽  
Dasom Kim ◽  
Eric H. Y. Lau ◽  
...  
Keyword(s):  
South Korea ◽  
Transmission Dynamics ◽  
Contact Tracing ◽  
Reproductive Number ◽  
Local Public Health ◽  
Social Distancing ◽  
Illness Onset ◽  
Sources Of Infection ◽  
The Impact ◽  
Epidemic Wave

Abstract Background After relaxing social distancing measures, South Korea experienced a resurgent second epidemic wave of coronavirus disease 2019 (COVID-19). In this study, we aimed to identify the transmission dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and assess the impact of COVID-19 case finding and contact tracing in each epidemic wave. Methods We collected data on COVID-19 cases published by local public health authorities in South Korea and divided the study into two epidemic periods (19 January–19 April 2020 for the first epidemic wave and 20 April–11 August 2020 for the second epidemic wave). To identify changes in the transmissibility of SARS-CoV-2, the daily effective reproductive number (Rt) was estimated using the illness onset of the cases. Furthermore, to identify the characteristics of each epidemic wave, frequencies of cluster types were measured, and age-specific transmission probability matrices and serial intervals were estimated. The proportion of asymptomatic cases and cases with unknown sources of infection were also estimated to assess the changes of infections identified as cases in each wave. Results In early May 2020, within 2-weeks of a relaxation in strict social distancing measures, Rt increased rapidly from 0.2 to 1.8 within a week and was around 1 until early July 2020. In both epidemic waves, the most frequent cluster types were religious-related activities and transmissions among the same age were more common. Furthermore, children were rarely infectors or infectees, and the mean serial intervals were similar (~ 3 days) in both waves. The proportion of asymptomatic cases at presentation increased from 22% (in the first wave) to 27% (in the second wave), while the cases with unknown sources of infection were similar in both waves (22 and 24%, respectively). Conclusions Our study shows that relaxing social distancing measures was associated with increased SARS-CoV-2 transmission despite rigorous case findings in South Korea. Along with social distancing measures, the enhanced contact tracing including asymptomatic cases could be an efficient approach to control further epidemic waves.

scholarly journals Transmission Dynamics and Control of Two Epidemic Waves of SARS-CoV-2 in South Korea

2021 ◽  
Author(s):  
Sukhyun Ryu ◽  
Sheikh Taslim Ali ◽  
Eunbi Noh ◽  
Dasom Kim ◽  
Eric H.Y. Lau ◽  
...  
Keyword(s):  
South Korea ◽  
Transmission Dynamics ◽  
Contact Tracing ◽  
Reproductive Number ◽  
Local Public Health ◽  
Social Distancing ◽  
Illness Onset ◽  
Sources Of Infection ◽  
The Impact ◽  
Epidemic Wave

Abstract Background: After relaxing social distancing measures, South Korea experienced a resurgent second epidemic wave of coronavirus disease 2019 (COVID-19). In this study, we aimed to identify the transmission dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and assess the impact of COVID-19 case finding and contact tracing in each epidemic wave.Methods: We collected data on COVID-19 cases published by local public health authorities in South Korea and divided the study into two epidemic periods (19 January–19 April 2020 for the first epidemic wave and 20 April–11 August 2020 for the second epidemic wave). To identify changes in the transmissibility of SARS-CoV-2, the daily effective reproductive number (Rt) was estimated using the illness onset of the cases. Furthermore, to identify the characteristics of each epidemic wave, frequencies of cluster types were measured, and age-specific transmission probability matrices and serial intervals were estimated. The proportion of asymptomatic cases and cases with unknown sources of infection were also estimated to assess the changes of infections identified as cases in each wave.Results: In early May 2020, within 2-weeks of a relaxation in strict social distancing measures, Rt increased rapidly from 0.2 to 1.8 within a week and was around 1 until early July 2020. In both epidemic waves, the most frequent cluster types were religious-related activities and transmissions among the same age were more common. Furthermore, children were rarely infectors or infectees, and the mean serial intervals were similar (~3 days) in both waves. The proportion of asymptomatic cases at presentation increased from 22% (in the first wave) to 27% (in the second wave), while the cases with unknown sources of infection were similar in both waves (22% and 24%, respectively).Conclusions: Our study shows that relaxing social distancing measures was associated with increased SARS-CoV-2 transmission despite rigorous case findings in South Korea. Along with social distancing measures, the enhanced contact tracing including asymptomatic cases could be an efficient approach to control further epidemic waves.

Epidemic cycle induced by intervention in a susceptibility-structured population

2014 ◽  
Vol 05 (supp01) ◽  
pp. 1441012
Author(s):  
Drandreb Earl Juanico
Keyword(s):  
Early Detection ◽  
Infectious Diseases ◽  
Epidemic Model ◽  
Finite Time ◽  
Social Distancing ◽  
Structured Population ◽  
Stochastic Epidemic ◽  
Stochastic Epidemic Model

Epidemics of infectious diseases have been known to recur in time. Diseases like influenza, despite intervention efforts through vaccination and targeted social distancing, continue to persist intermittently in the population. I have undertaken an analysis of a stochastic epidemic model with the hypothesis that intervention drives epidemic cycles. Intervention indeed is found to induce cycles of epidemic activity. Above a minimum intervention rate, however, activity dies out in finite time. The susceptibility structure of a community could be easily infused into the design of existing surveillance protocols. By tracking that structure, early detection of an impending outbreak is enhanced.

CONSIDERATION OF MODELS AND MECHANISMS OF PUBLIC ADMINISTRATION OF PROCUREMENT OF GOODS, WORKS AND SERVICES IN CONSTRUCTION IN UKRAINE

2018 ◽  
Vol 1 (13) ◽  
pp. 131-142
Author(s):  
Tetyana Konstantinovna Mitropan
Keyword(s):  
Public Administration ◽  
Construction Industry ◽  
High Efficiency ◽  
Public Procurement ◽  
Combined Model ◽  
Single Body ◽  
Construction Products ◽  
Model Of Management ◽  
Decentralized Model ◽  
Centralized Model

The article presents the questions of reviewing models and mechanisms of public administration in the procurement of goods, works and services in the field of construction. A comparative analysis of the types of public procurement mechanisms in construction, based on a set of features, has shown the superiority of a centralized type of mechanism that facilitates the introduction of efficient and flexible procurement methods, for example, the conclusion of framework agreements. The author’s vision of the mechanism of state building purchases, in the form of a conceptual model and system differences, is proposed. It is determined that a decentralized model of public procurement management involves the independent implementation by purchasers of procurement, that is, allows each customer to procure goods, works and services in the field of construction. The centralized model of public administration is characterized by the implementation of public procurement in order to provide the general needs of a single body on public procurement, that is, customers commission the implementation of public procurement on their behalf, a centralized body. According to the combined model of management, public procurement in the construction industry takes place under contracts implemented under the centralized model, and the direct ordering and receipt of goods, works, or services takes place according to the rules of a decentralized model. It is noted that according to the system-wide understanding of the mechanism of public administration in the procurement of goods, works and services in the field of construction, it represents a set of specialized management technologies (methods, techniques and tools) that ensure the organization of the process of public procurement of construction products by authorized agents. The direction of this process is determined by the need to implement the principles of vali- dity and innovation, fair choice of the best bidding, prevention of corruption and ensuring the high efficiency of the implementation of public public procurement.

Are social networking platforms the key to effective social distancing for COVID-19? (Preprint)

2020 ◽  
Author(s):  
Viknesh Sounderajah ◽  
Hutan Ashrafian ◽  
Sheraz Markar ◽  
Ara Darzi
Keyword(s):  
Operating System ◽  
Social Networking ◽  
Contact Tracing ◽  
Text Data ◽  
Social Distancing ◽  
Web Mapping ◽  
Viral Spread ◽  
Behavioural Insights ◽  
Mapping Software ◽  
Incidence And Mortality

UNSTRUCTURED If health systems are to effectively employ social distancing measures to in response to further COVID-19 peaks, they must adopt new behavioural metrics that can supplement traditional downstream measures, such as incidence and mortality. Access to mobile digital innovations may dynamically quantify compliance to social distancing (e.g. web mapping software) as well as establish personalised real-time contact tracing of viral spread (e.g. mobile operating system infrastructure through Google-Apple partnership). In particular, text data from social networking platforms can be mined for unique behavioural insights, such as symptom tracking and perception monitoring. Platforms, such as Twitter, have shown significant promise in tracking communicable pandemics. As such, it is critical that social networking companies collaborate with each other in order to (1) enrich the data that is available for analysis, (2) promote the creation of open access datasets for researchers and (3) cultivate relationships with governments in order to affect positive change.

scholarly journals Effects of social distancing on the spreading of COVID-19 inferred from mobile phone data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamid Khataee ◽  
Istvan Scheuring ◽  
Andras Czirok ◽  
Zoltan Neufeld
Keyword(s):  
Mobile Phone ◽  
Basic Reproductive Number ◽  
Mobile Phone Data ◽  
Reproductive Number ◽  
Expansion Phase ◽  
Social Distancing ◽  
Exponential Expansion ◽  
Total Death ◽  
Mobility Reduction ◽  
Epidemiological Parameters

AbstractA better understanding of how the COVID-19 pandemic responds to social distancing efforts is required for the control of future outbreaks and to calibrate partial lock-downs. We present quantitative relationships between key parameters characterizing the COVID-19 epidemiology and social distancing efforts of nine selected European countries. Epidemiological parameters were extracted from the number of daily deaths data, while mitigation efforts are estimated from mobile phone tracking data. The decrease of the basic reproductive number ($$R_0$$ R 0 ) as well as the duration of the initial exponential expansion phase of the epidemic strongly correlates with the magnitude of mobility reduction. Utilizing these relationships we decipher the relative impact of the timing and the extent of social distancing on the total death burden of the pandemic.

scholarly journals TraceAll: A Real-Time Processing for Contact Tracing Using Indoor Trajectories

Information ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 202
Author(s):  
Louai Alarabi ◽  
Saleh Basalamah ◽  
Abdeltawab Hendawi ◽  
Mohammed Abdalla
Keyword(s):  
Infectious Diseases ◽  
Infected Patient ◽  
Public Health Problem ◽  
Real Data ◽  
Exposure Period ◽  
Contact Tracing ◽  
Data Sets ◽  
Major Public Health Problem ◽  
Real Time Processing ◽  
Recent Developments

The rapid spread of infectious diseases is a major public health problem. Recent developments in fighting these diseases have heightened the need for a contact tracing process. Contact tracing can be considered an ideal method for controlling the transmission of infectious diseases. The result of the contact tracing process is performing diagnostic tests, treating for suspected cases or self-isolation, and then treating for infected persons; this eventually results in limiting the spread of diseases. This paper proposes a technique named TraceAll that traces all contacts exposed to the infected patient and produces a list of these contacts to be considered potentially infected patients. Initially, it considers the infected patient as the querying user and starts to fetch the contacts exposed to him. Secondly, it obtains all the trajectories that belong to the objects moved nearby the querying user. Next, it investigates these trajectories by considering the social distance and exposure period to identify if these objects have become infected or not. The experimental evaluation of the proposed technique with real data sets illustrates the effectiveness of this solution. Comparative analysis experiments confirm that TraceAll outperforms baseline methods by 40% regarding the efficiency of answering contact tracing queries.

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