The challenges of containing SARS-CoV-2 via test-trace-and-isolate

Abstract

Without a cure, vaccine, or proven long-term immunity against SARS-CoV-2, test-trace-and-isolate (TTI) strategies present a promising tool to contain its spread. For any TTI strategy, however, mitigation is challenged by pre- and asymptomatic transmission, TTI-avoiders, and undetected spreaders, who strongly contribute to hidden infection chains. Here, we studied a semi-analytical model and identified two tipping points between controlled and uncontrolled spread: (1) the behavior-driven reproduction number of the hidden chains becomes too large to be compensated by the TTI capabilities, and (2) the number of new infections exceeds the tracing capacity. Both trigger a self-accelerating spread. We investigated how these tipping points depend on challenges like limited cooperation, missing contacts, and imperfect isolation. Our model results suggest that TTI alone is insufficient to contain an otherwise unhindered spread of SARS-CoV-2, implying that complementary measures like social distancing and improved hygiene remain necessary.

References in corpus (4)

• Evidence of economic segregation from mobility lockdown during COVID-19 epidemic
• Inferring change points in the COVID-19 spreading reveals the effectiveness of interventions
• Stochasticity and heterogeneity in the transmission dynamics of SARS-CoV-2
• Statistically-based methodology for revealing real contagion trends and correcting delay-induced errors in the assessment of COVID-19 pandemic

Cited by in corpus (12)

• A look into the future of the COVID-19 pandemic in Europe: an expert consultation
• Relaxing restrictions at the pace of vaccination increases freedom and guards against further COVID-19 waves
• Low case numbers enable long-term stable pandemic control without lockdowns
• A control theory approach to optimal pandemic mitigation
• Epidemic Management and Control Through Risk-Dependent Individual Contact Interventions
• Impact of the Euro 2020 championship on the spread of COVID-19
• On the heterogeneous spread of COVID-19 in Chile
• Routing algorithms as tools for integrating social distancing with emergency evacuation
• Model-based assessment of sampling protocols for infectious disease genomic surveillance
• A mechanistic model to assess the effectiveness of test-trace-isolate-and-quarantine under limited capacities
• Nonlinear dynamics of an epidemic compartment model with asymptomatic infections and mitigation
• Effectiveness of probabilistic contact tracing in epidemic containment: the role of super-spreaders and transmission path reconstruction