Digital Contact Tracing Research Articles

Sovereignty in the Digital and Contact Tracing Apps

Recently, the concept of sovereignty in the digital has attracted much attention. Several publications dealing with this concept assume that it can best be described as a network of different, overlapping exercises of power. Nevertheless, there is a need for further research on how exactly sovereignty in the digital can be understood. In order to contribute to a better understanding of this concept, I illustrate its complex structure using contact tracing apps as a paradigmatic example. I conduct a narrative review to show what sovereignty looks like in the context of these apps. In the context of digital contact tracing apps, sovereignty is best understood as a complex network of three actors—nations, (big tech) companies, and individuals—that exercise various forms of power against or on behalf of each other to claim sovereignty for themselves and to either weaken or strengthen the sovereignty claims of other actors. Since large parts of the results can be generalized from the particular context of contact tracing apps, they contribute to a better overall understanding of the concept of sovereignty in digital. This might, in turn, be helpful for discussions about this technology as well as about the regulation and governance of the digital in general.

Analysis of digital contact tracing technologies employed during COVID-19 Pandemic

Corona virus (COVID-19) is a worldwide pandemic that was first reported in Wuhan, China 2019.The virus claimed lives and negatively changed the mobility patterns of humans. As a measure to control the spread of the virus, Digital Contact Tracing Technologies (DCTTs) were employed to contain the virus. The (DCTTs) are used to track and notify users digitally about their interactions with infected individuals and help strengthen health service systems. The most widely used Digital Contact Tracing Technologies include those that use Global Positioning, Bluetooth, Quick Response (QR) Codes and Wireless Fidelity (Wi-Fi). These technologies depend on monitoring symptoms, mobility of a person, location and proximity of individuals. This paper reviews literature by analyzing the Digital Contact Tracing Technologies (DCTTs) employed for COVID-19 through a desk study. The review highlights the advantages and disadvantages of using these technologies, with an aim of recommending ways in which the technologies can be used to attain maximum benefit.

Indoor Spatiotemporal Contact Analytics Using Landmark-Aided Pedestrian Dead Reckoning on Smartphones.

Due to the prevalence of COVID-19, providing safe environments and reducing the risks of virus exposure play pivotal roles in our daily lives. Contact tracing is a well-established and widely-used approach to track and suppress the spread of viruses. Most digital contact tracing systems can detect direct face-to-face contact based on estimated proximity, without quantifying the exposed virus concentration. In particular, they rarely allow for quantitative analysis of indirect environmental exposure due to virus survival time in the air and constant airborne transmission. In this work, we propose an indoor spatiotemporal contact awareness framework (iSTCA), which explicitly considers the self-containing quantitative contact analytics approach with spatiotemporal information to provide accurate awareness of the virus quanta concentration in different origins at various times. Smartphone-based pedestrian dead reckoning (PDR) is employed to precisely detect the locations and trajectories for distance estimation and time assessment without the need to deploy extra infrastructure. The PDR technique we employ calibrates the accumulative error by identifying spatial landmarks automatically. We utilized a custom deep learning model composed of bidirectional long short-term memory (Bi-LSTM) and multi-head convolutional neural networks (CNNs) for extracting the local correlation and long-term dependency to recognize landmarks. By considering the spatial distance and time difference in an integrated manner, we can quantify the virus quanta concentration of the entire indoor environment at any time with all contributed virus particles. We conducted an extensive experiment based on practical scenarios to evaluate the performance of the proposed system, showing that the average positioning error is reduced to less than 0.7 m with high confidence and demonstrating the validity of our system for the virus quanta concentration quantification involving virus movement in a complex indoor environment.

Understanding the impact of digital contact tracing during the COVID-19 pandemic.

Digital contact tracing (DCT) applications have been introduced in many countries to aid the containment of COVID-19 outbreaks. Initially, enthusiasm was high regarding their implementation as a non-pharmaceutical intervention (NPI). However, no country was able to prevent larger outbreaks without falling back to harsher NPIs. Here, we discuss results of a stochastic infectious-disease model that provide insights in how the progression of an outbreak and key parameters such as detection probability, app participation and its distribution, as well as engagement of users impact DCT efficacy informed by results of empirical studies. We further show how contact heterogeneity and local contact clustering impact the intervention's efficacy. We conclude that DCT apps might have prevented cases on the order of single-digit percentages during single outbreaks for empirically plausible ranges of parameters, ignoring that a substantial part of these contacts would have been identified by manual contact tracing. This result is generally robust against changes in network topology with exceptions for homogeneous-degree, locally-clustered contact networks, on which the intervention prevents more infections. An improvement of efficacy is similarly observed when app participation is highly clustered. We find that DCT typically averts more cases during the super-critical phase of an epidemic when case counts are rising and the measured efficacy therefore depends on the time of evaluation.

Dutch public health professionals’ perspectives and needs regarding citizen involvement in COVID-19 contact tracing through digital support tools: an exploratory qualitative study

BackgroundContact tracing (CT) is an important, but resource-intensive tool to control outbreaks of communicable diseases. Under pandemic circumstances, public health services may not have sufficient resources at their disposal to effectively facilitate CT. This may be addressed by giving cases and their contact persons more autonomy and responsibility in the execution of CT by public health professionals, through digital contact tracing support tools (DCTS-tools). However, the application of this approach has not yet been systematically investigated from the perspective of public health practice. Therefore, we investigated public health professionals’ perspectives and needs regarding involving cases and contact persons in CT for COVID-19 through DCTS-tools.MethodsBetween October 2020 and February 2021, we conducted online semi-structured interviews (N = 17) with Dutch public health professionals to explore their perspectives and needs regarding the involvement of cases and contact persons in CT for COVID-19 through DCTS-tools, in the contact identification, notification, and monitoring stages of the CT-process. Interviews were audio recorded and transcribed verbatim. A thematic analysis was performed.ResultsFour main themes related to Dutch public health professionals’ perspectives and needs regarding involving cases and contact persons in CT for COVID-19 through DCTS-tools emerged from the data: ‘Distinct characteristics of CT with DCTS-tools’; ‘Anticipated benefits and challenges of CT for COVID-19 with DCTS- tools’; ‘Circumstances in CT for COVID-19 that permit or constrain the application of DCTS-tools’; and ‘Public health professionals’ needs regarding the development and application of DCTS-tools for CT’. Public health professionals seem to have a positive attitude towards involving cases and contact persons through DCTS-tools. Public health professionals’ (positive) attitudes seem conditional on the circumstances under which CT is performed, and the fulfilment of their needs in the development and application of DCTS-tools.ConclusionsDutch public health professionals seem positive towards involving cases and contact persons in CT for COVID-19 through DCTS-tools. Through adequate implementation of DCTS-tools in the CT-process, anticipated challenges can be overcome. Future research should investigate the perspectives and needs of cases and contact persons regarding DCTS-tools, and the application of DCTS-tools in practice.

Performance of the Swiss Digital Contact-Tracing App Over Various SARS-CoV-2 Pandemic Waves: Repeated Cross-sectional Analyses.

Digital proximity-tracing apps have been deployed in multiple countries to assist with SARS-CoV-2 pandemic mitigation efforts. However, it is unclear how their performance and effectiveness were affected by changing pandemic contexts and new viral variants of concern. The aim of this study is to bridge these knowledge gaps through a countrywide digital proximity-tracing app effectiveness assessment, as guided by the World Health Organization/European Center for Prevention and Disease Control (WHO/ECDC) indicator framework to evaluate the public health effectiveness of digital proximity-tracing solutions. We performed a descriptive analysis of the digital proximity-tracing app SwissCovid in Switzerland for 3 different periods where different SARS-CoV-2 variants of concern (ie, Alpha, Delta, and Omicron, respectively) were most prevalent. In our study, we refer to the indicator framework for the evaluation of public health effectiveness of digital proximity-tracing apps of the WHO/ECDC. We applied this framework to compare the performance and effectiveness indicators of the SwissCovid app. Average daily registered SARS-CoV-2 case rates during our assessment period from January 25, 2021, to March 19, 2022, were 20 (Alpha), 54 (Delta), and 350 (Omicron) per 100,000 inhabitants. The percentages of overall entered authentication codes from positive tests into the SwissCovid app were 9.9% (20,273/204,741), 3.9% (14,372/365,846), and 4.6% (72,324/1,581,506) during the Alpha, Delta, and Omicron variant phases, respectively. Following receipt of an exposure notification from the SwissCovid app, 58% (37/64, Alpha), 44% (7/16, Delta), and 73% (27/37, Omicron) of app users sought testing or performed self-tests. Test positivity among these exposure-notified individuals was 19% (7/37) in the Alpha variant phase, 29% (2/7) in the Delta variant phase, and 41% (11/27) in the Omicron variant phase compared to 6.1% (228,103/3,755,205), 12% (413,685/3,443,364), and 41.7% (1,784,951/4,285,549) in the general population, respectively. In addition, 31% (20/64, Alpha), 19% (3/16, Delta), and 30% (11/37, Omicron) of exposure-notified app users reported receiving mandatory quarantine orders by manual contact tracing or through a recommendation by a health care professional. In constantly evolving pandemic contexts, the effectiveness of digital proximity-tracing apps in contributing to mitigating pandemic spread should be reviewed regularly and adapted based on changing requirements. The WHO/ECDC framework allowed us to assess relevant domains of digital proximity tracing in a holistic and systematic approach. Although the Swisscovid app mostly worked, as reasonably expected, our analysis revealed room for optimizations and further performance improvements. Future implementation of digital proximity-tracing apps should place more emphasis on social, psychological, and organizational aspects to reduce bottlenecks and facilitate their use in pandemic contexts.

Use of temporal contact graphs to understand the evolution of COVID-19 through contact tracing data

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, indicating a sub-sampled dataset would be as good at prediction. At individual level, however, the temporal contact graph plays a limited role, since the behavior distinction between the infected and uninfected 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.

Individual costs and community benefits: Collectivism and individuals' compliance with public health interventions.

Differences in national responses to COVID-19 have been associated with the cultural value of collectivism. The present research builds on these findings by examining the relationship between collectivism at the individual level and adherence to public health recommendations to combat COVID-19 during the pre-vaccination stage of the pandemic, and examines different characteristics of collectivism (i.e., concern for community, trust in institutions, perceived social norms) as potential psychological mechanisms that could explain greater compliance. A study with a cross-section of American participants (N = 530) examined the relationship between collectivism and opting-in to digital contact tracing (DCT) and wearing face coverings in the general population. More collectivistic individuals were more likely to comply with public health interventions than less collectivistic individuals. While collectivism was positively associated with the three potential psychological mechanisms, only perceived social norms about the proportion of people performing the public health interventions explained the relationship between collectivism and compliance with both public health interventions. This research identifies specific pathways by which collectivism can lead to compliance with community-benefiting public health behaviors to combat contagious diseases and highlights the role of cultural orientation in shaping individuals' decisions that involve a tension between individual cost and community benefit.

The German COVID-19 Digital Contact Tracing App: A Socioeconomic Evaluation.

The COVID-19 pandemic posed challenges to governments in terms of contact tracing. Like many other countries, Germany introduced a mobile-phone-based digital contact tracing solution ("Corona Warn App"; CWA) in June 2020. At the time of its release, however, it was hard to assess how effective such a solution would be, and a political and societal debate arose regarding its efficiency, also in light of its high costs. This study aimed to analyze the effectiveness of the CWA, considering prevented infections, hospitalizations, intensive care treatments, and deaths. In addition, its efficiency was to be assessed from a monetary point of view, and factors with a significant influence on the effectiveness and efficiency of the CWA were to be determined. Mathematical and statistical modeling was used to calculate infection cases prevented by the CWA, along with the numbers of prevented complications (hospitalizations, intensive care treatments, deaths) using publicly available CWA download numbers and incidences over time. The monetized benefits of these prevented cases were quantified and offset against the costs incurred. Sensitivity analysis was used to identify factors critically influencing these parameters. Between June 2020 and April 2022, the CWA prevented 1.41 million infections, 17,200 hospitalizations, 4600 intensive care treatments, and 7200 deaths. After offsetting costs and benefits, the CWA had a net present value of EUR 765 m in April 2022. Both the effectiveness and efficiency of the CWA are decisively and disproportionately positively influenced by the highest possible adoption rate among the population and a high rate of positive infection test results shared via the CWA.

The relationship between trust and attitudes towards the COVID-19 digital contact-tracing app in the UK.

During the COVID-19 pandemic, digital contact-tracing has been employed in many countries to monitor and manage the spread of the disease. However, to be effective such a system must be adopted by a substantial proportion of the population; therefore, public trust plays a key role. This paper examines the NHS COVID-19 smartphone app, the digital contact-tracing solution in the UK. A series of interviews were carried out prior to the app's release (n = 12) and a large scale survey examining attitudes towards the app (n = 1,001) was carried out after release. Extending previous work reporting high level attitudes towards the app, this paper shows that prevailing negative attitudes prior to release persisted, and affected the subsequent use of the app. They also show significant relationships between trust, app features, and the wider social and societal context. There is lower trust amongst non-users of the app and trust correlates to many other aspects of the app, a lack of trust could hinder adoption and effectiveness of digital contact-tracing. The design of technology requiring wide uptake, e.g., for public health, should embed considerations of the complexities of trust and the context in which the technology will be used.

A centralized contact-tracing protocol for the COVID-19 pandemic

Digital contact tracing (DCT) is one of the weapons to be used against the COVID-19 pandemic, especially in a post-lockdown phase, to prevent or block foci of infection. As DCT systems can handle highly private information about people, great care must be taken to prevent misuse of the system and actions detrimental to people’s privacy, up to mass surveillance. This paper presents a new centralized DCT protocol, called ZE2-P3T (Zero Ephemeral Exchanging Privacy-Preserving Proximity Protocol), which relies on smartphone localization but does not give any information about the user’s location and identity to the server. Importantly, the fact that no exchange of ephemeral identities among users is required is the basis of the strong security of the protocol, which is proven to be more secure than the state-of-the-art protocol DP-3T/GAEN.

Systematic review on digitals tools used for contact tracing of COVID-19 patients: interim results

Abstract Background Contact tracing is a public health intervention implemented in synergy with other measures, such as testing, physical distancing, and vaccination, to curb the COVID-19 pandemic. Digital solutions have been developed worldwide to enhance the contact tracing process. The aim of the study was to evaluate the effectiveness and impact of tracking COVID-19 patients using digital tools. Methods A systematic literature review was performed on eight online databases to identify observational studies on digital contact tracing, published 2020-2021, in English. Studies identified through the ‘Population Health Information Research Infrastructure’ project were also included. An ad hoc form has been deployed for data extraction of relevant information. Quality assessment of the included studies will be performed using validated tools. Results Over 8000 records were identified, of which 27 met the inclusion criteria: 16 modelling and 11 population-based studies. A study was based on GPS technology, four were Bluetooth-based, and others used digital technologies and manual tracing. The uptake rate of the tools ranged 19-100% across the studies. Most studies compared digital contact tracing with other strategies (e.g., no intervention, lockdown). Digital contact tracing was associated with improved identification of contact persons (9 studies), reduction of the effective reproduction number or covid-19 infections (8 studies), and increased effectiveness in combination with other containment measures (9 studies). Security and privacy issues were considered in 8 studies. Conclusions Digital contact tracing contributes in reducing further transmission, especially with sufficient population uptake of the applications and in combination with other public health measures. However, its deployment has been limited by security and privacy issues. Further studies are required to investigate the combined impact of digital and conventional contact tracing and enhance privacy and security.

1.Q. Workshop: Summarising research evidence related to COVID-19 impact

Abstract After the first SARS-CoV-2 infections surge in late 2019, and its spreading worldwide, COVID-19 rapidly became a pandemic by March 2020. Facing a new public health crisis, the scientific community deployed research efforts to study this new disease, generating a large amount of scientific evidence in a very fast way. This research was developed in several directions, for instance, describing how COVID-19 impacts the population's health and well-being. Specifically, the research aimed at describing and evaluating the risk factors either for being infected or evolving toward adverse outcomes, such as hospitalisation or death. Moreover, the effectiveness of implemented public health measures was assessed since countries’ governments rapidly implemented them to mitigate the pandemic.Therefore, several literature reviews have been performed within the European Project ‘Population Health Information Research Infrastructure (PHIRI)’ to summarise and share the published COVID-19 evidence through a health information portal, where researchers and other stakeholders can exchange best practices and expertise. This workshop aims at sharing the collaborative work and experience of a large group of European researchers within the PHIRI consortium, consisting in preliminary results and lessons learnt with the scientific community. The workshop format consists of five presentations by PHIRI members, each one presenting their literature review work, followed by a discussion among the presenters and with the audience. The first workshop presentation will describe the methodological aspects of research conducted to assess the COVID-19 impact on the population's health and well-being, including research methods and statistical methods. The subject for the second talk will show a representative sample of health indicators used to evaluate the direct impact of COVID-19 in the scientific literature. The third presentation will elaborate on a short and long-term impact of COVID-19 crisis on population with frailty, multimorbidity or with different socioeconomic status; evidence derived from systematic literature reviews of population-based studies. The fourth presentation will describe the effectiveness and impact of tracking COVID-19 patients using digital contact tracing tools. The last presentation describes the methodological aspects of a systematic literature review conducted to gain an overview of the foresight studies that have been done throughout the World about COVID-19. Key messages • During the pandemic, a literature reviews provide an important tool to summarise the large amount of scientific evidence that was generated. • This workshop aims at sharing the collaborative work and experience of a large group of European researchers participating at PHIRI, the results and lessons learned with the scientific community.

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Contact Tracing Strategies for COVID-19 Prevention and Containment: A Scoping Review

Coronavirus Disease 2019 (COVID-19) spreads rapidly and is easily contracted by individuals who come near infected persons. With this nature and rapid spread of the contagion, different types of research have been conducted to investigate how non-pharmaceutical interventions can be employed to contain and prevent COVID-19. In this review, we analyzed the key elements of digital contact tracing strategies developed for the prevention and containment of the dreaded epidemic since its outbreak. We carried out a scoping review through relevant studies indexed in three databases, namely Google Scholar, PubMed, and ACM Digital Library. Using some carefully defined search terms, a total of 768 articles were identified. The review shows that 86.32% (n = 101) of the works focusing on contact tracing were published in 2020, suggesting there was an increased awareness that year, increased research efforts, and the fact that the pandemic was given a very high priority by most journals. We observed that many (47.86%, n = 56) of the studies were focused on design and implementation issues in the development of COVID-19 contact tracing systems. In addition, has been established that most of the studies were conducted in 41 countries and that contract tracing app development are characterized by some sensitive issues, including privacy-preserving and case-based referral characteristics.

COVID-19 contact tracing apps and the governance of collective action: social nudges, deliberation, and solidarity in Europe and beyond

ABSTRACT During the COVID-19 pandemic, Digital Contact Tracing (DCT) tools were deployed by governments in Europe and beyond as a novel mobile technology to assist traditional manual contact tracing to track individuals who have come in close contact with an infected person. The public debate on this topic focused strongly on the protection of individual privacy. While this debate is important, it fails to address important governance questions – such as, for example, that DCT tools took on the role of social nudges, namely, tools of soft regulation that calibrate information flows so as to “push” people to act in ways that promote collective purposes. Social nudges include a range of norms and values that, however, are built into the technological and social features of the nudge, rather than rendering them open to public scrutiny and debate. Although the use of contact tracing apps is being phased out, the digitization of contact tracing can be seen as a case study of the broader trend towards digitization of the provision of health services. Debates of their governance thus have broader implications for the governance of data driven tools deployed for public health purposes in times of crisis.

On the Feasibility of Linking Attack to Google/Apple Exposure Notification Framework

Digital contact-tracing (DCT) applications have been installed on more than 188 M smartphones worldwide as an effective mechanism for monitoring contact with COVID-19 infected individuals. DCT is promising not only for COVID-19, but also for preparing for a possible future large-scale pandemic. The DCT framework is unique in that it combines Bluetooth Low Energy (BLE) communications with cryptography techniques to track exposure on a large scale while protecting user privacy. The objective of this study is to assess the risk of the linking attack to the DCT frameworks; i.e., linking individuals to the identifiers contained in BLE broadcast frames that are supposed to be anonymized. Specifically, we target Google/Apple’s Exposure Notification (GAEN), which is the representative implementation of DCT. Our extensive experiments demonstrate that passively collected rolling proximity identifiers (RPIs) contained in the BLE frames can be linked to face photos which could lead to the exposure of privacy information with high accuracy, including infection status. We also demonstrate that an attacker with a few number of devices can correctly link RPIs and the images of the target person with a success rate of 86% at a rate of 5,000 users per hour. Based on these results, we propose countermeasures to reduce the inherent privacy risk of the GAEN framework.

Replay (Far) Away: Exploiting and Fixing Google/Apple Exposure Notification Contact Tracing

Digital contact tracing offers significant promise to help reduce the spread of SARS-CoV-2 and other viruses. Google and Apple joined together in 2020 to create the Google/Apple Exposure Notification (GAEN) framework to determine encounters with anonymous users later diagnosed COVID-19 positive. However, as GAEN lacks geospatial awareness, it is susceptible to geographically distributed replay attacks. Anonymous, low-cost, crowd-sourced replay attack networks deployed by malicious actors (or far away nation-state attackers) who utilize malicious (or innocent) users’ smartphones to capture and replay GAEN advertisements can drastically increase false-positive rates even in areas that otherwise exhibit low positivity rates. In response to this powerful replay attack, we introduce GAEN+ , a solution that enhances GAEN with geospatial awareness while maintaining user privacy, and demonstrate its ability to effectively prevent geographically distributed replay attacks.

Digital contact tracing in epidemics: fast tracking the future

The COVID pandemic has brought unprecedented changes in the current healthcare model, more as a necessity than by choice. The rapid unraveling of the pandemic has fast tracked the use of technology and artificial intelligence in healthcare systems by identifying and implementing more efficient processes to mitigate the crisis. Digital contact tracing technology (DCTT) has been hailed as the savior for opening up the community towards some semblance to the previous normal. Understanding contact tracing as both a proactive tool in the containing of an epidemics and as a reactive tool in limiting damages after spread is of utmost importance before taking a call into its effectiveness and implication on privacy of the individuals involved. The current pandemic response is like building a plane during its flight, and hence the risks involved in understanding the disease and mitigating the problems due to the novel nature of the disease needs to be done in real time. The political and social outcries on the use of DCTT are enough reasons for caution in applying previously unperfected technologies in diseases whose natural course has not yet been fully understood. The relationship between epidemics and contact tracing, conventional contact tracing, DCTT, different models of DCTT used during the current epidemic, limitations of DCTT and the future of incorporating DCTT into healthcare systems from the view of epidemiology and patient safety will be the primary focus of this article.