Lateral contact tracing and outbreak control in large gatherings

This article was originally published here

SocJR interface. 2022 May;19(190):20220048. doi: 10.1098/rsif.2022.0048. Published online May 11, 2022.


Effective contact tracing is essential to contain the spread of the epidemic without disrupting societal activities, especially during a pandemic. Large gatherings play a key role, potentially favoring superspreader events. However, the effects of tracing in large groups have not been fully assessed so far. We show that in addition to forward tracing, which reconstructs who the disease is spreading to, and backward tracing, which seeks from whom the disease is spreading, a third “lateral” tracing is always present. , when tracing gatherings. This is an indirect tracing that detects asymptomatic infected individuals, even if they were neither directly infected nor directly transmitted the infection to the index case. We analyze this effect in a model of epidemic spread of SARS-CoV-2, within the framework of activity-driven simplicial temporal networks. We determine the contribution of the three tracing mechanisms to the suppression of epidemic spread, showing that lateral tracing induces a non-monotonic behavior in tracing efficiency, depending on the size of the gatherings. Based on our results, we propose an optimal choice for the sizes of the gatherings to be traced and we test the strategy on an empirical dataset of gatherings on a university campus.

PMID:35537473 | DOI:10.1098/rsif.2022.0048