Superspreading k-cores at the center of COVID-19 pandemic persistence

TL;DR

This study analyzes COVID-19 contact networks to identify persistent superspreading structures, proposing targeted quarantine strategies that could effectively disrupt transmission with minimal societal disruption.

Contribution

It introduces a network-based approach to identify superspreading k-cores and suggests optimized quarantine strategies targeting key 'weak links' to control the pandemic.

Findings

Mobility decreased by ~53% during lockdowns, reducing transmission network connectivity by ~90%.

Superspreading k-core structures persist despite mobility reductions.

Targeted quarantine of high betweenness centrality links can effectively break transmission chains.

Abstract

The spread of COVID-19 caused by the recently discovered SARS-CoV-2 virus has become a worldwide problem with devastating consequences. To slow down the spread of the pandemic, mass quarantines have been implemented globally, provoking further social and economic disruptions. Here, we implement a comprehensive contact tracing network analysis to find an optimized quarantine protocol to dismantle the chain of transmission of coronavirus with minimal disruptions to society. We track billions of anonymized GPS human mobility datapoints from a compilation of hundreds of mobile apps deployed in Latin America to monitor the evolution of the contact network of disease transmission before and after the confinements. As a consequence of the lockdowns, people's mobility across the region decreases by $\sim$53\%, which results in a drastic disintegration of the transmission network by $\sim$90\%. However, this disintegration did not halt the spreading of the disease. Our analysis indicates that superspreading k-core structures persist in the transmission network to prolong the pandemic. Once the k-cores are identified, an optimized strategy to break the chain of transmission is to quarantine a minimal number of 'weak links' with high betweenness centrality connecting the large k-cores. As countries built contact tracing apps to fight the pandemic, our results could turn into a valuable resource to help deploy quarantine protocols with minimized disruptions.