Modelling digital and manual contact tracing for COVID-19. Are low uptakes and missed contacts deal-breakers?

Abstract

Comprehensive testing schemes, followed by adequate contact tracing and isolation, represent the best public health interventions we can employ to reduce the impact of an ongoing epidemic when no or limited vaccine supplies are available and the implications of a full lockdown are to be avoided. However, the process of tracing can prove feckless for highly-contagious viruses such as SARS-CoV-2. The interview-based approaches often miss contacts and involve significant delays, while digital solutions can suffer from insufficient adoption rates or inadequate usage patterns. Here we present a novel way of modelling different contact tracing strategies, using a generalized multi-site mean-field model, which can naturally assess the impact of manual and digital approaches alike. Our methodology can readily be applied to any compartmental formulation, thus enabling the study of more complex pathogen dynamics. We use this technique to simulate a newly-defined epidemiological model, SEIR-T, and show that, given the right conditions, tracing in a COVID-19 epidemic can be effective even when digital uptakes are sub-optimal or interviewers miss a fair proportion of the contacts.

Spreading processes with mutations over multilayer networks

“…Overlaying this, we might have multiple layers, each representing a specific age group or a demographic to represent the additional connectivity we expect among that group. It is also of interest to investigate the impact of rare events of untraceable contacts and develop models to account for untraceable nodes and contacts in contact-tracing tools ( 71 ). Finally, in the context of social networks, a promising future application is to leverage models for multistrain spreading to combat the spread of misinformation across different social media platforms.…”

EpiCURB: Learning to Derive Epidemic Control Policies

“…Unfortunately, "test and trace" programmes often suffer from potentially crippling inadequacies. 3,4 First of all, manual tracing is upper bounded by staff numbers and their efficiency, leading to intrinsic delays, 19 with memory fallacies of positively-tested individuals often ensuing. 20 Digital tracing, on the other hand, is rarely optimally adopted by populations, 19 with issues such as smartphone access, Bluetooth reliability or privacy concerns being important determining factors.…”

“…Balancing NPIs between their individual effectiveness and limitations, their co-occurrence and potentially inflicting major unintended consequences has been a persistent challenge for authorities around the globe. 1,2 This article demonstrates how simulation-based methods, relying on the recently-introduced EpiCURB framework 3 and the SEIR-T individual-based mean-field model, 4 along with suitable visualization tools, can support policy makers in optimizing such decisions and the budgets allocated for each intervention.…”

“…With a cost-based model of enhancing the intensity and budget of each NPI, authorities would be able to decide which action is more effective based off such simulated outcomes. Although our method utilizes an individualbased mean-field model specific for the SARS-CoV-2 virus, 3,4 our approach can be used to study any other pathogen, present or future, provided that it can be described via similar equationbased formulations.…”

Mathematical modeling of contact tracing and stability analysis to inform its impact on disease outbreaks; an application to COVID-19

“…From a mathematical perspective, modelling the process of contact tracing itself, was also subject of study for numerous research papers ( Browne, Gulbudak, & Webb, 2015 ; Huo, 2015 ; Hyman, Li, & Stanley, 2003 ; Kwok et al., 2019 ; Müller & Kretzschmar, 2021a ; Rusu, Emonet, & Farrahi, 2021 ; Tsimring & Huerta, 2003 ). Different approaches to address the question were followed.…”