The reachability of contagion in temporal contact networks: how disease latency can exploit the rhythm of human behavior

TL;DR

This study investigates how the timing of disease latency relative to human social activity rhythms influences disease spread in contact networks, revealing peaks in contagion risk at specific latent periods like 24 hours or 7 days.

Contribution

It introduces a model linking disease latency with social behavior rhythms and demonstrates how this synchronization affects contagion reachability using real social interaction data.

Findings

Peak contagion risk occurs at 24-hour and 7-day latent periods.

Synchronization of latency with social activity increases disease reach.

The relationship between latency and spread is non-linear and context-dependent.

Abstract

The symptoms of many infectious diseases influence their host to withdraw from social activity limiting their own potential to spread. Successful transmission therefore requires the onset of infectiousness to coincide with a time when its host is socially active. Since social activity and infectiousness are both temporal phenomena, we hypothesize that diseases are most pervasive when these two processes are synchronized. We consider disease dynamics that incorporate a behavioral response that effectively shortens the infectious period of the disease. We apply this model to data collected from face-to-face social interactions and look specifically at how the duration of the latent period effects the reachability of the disease. We then simulate the spread of the model disease on the network to test the robustness of our results. Diseases with latent periods that synchronize with the temporal social behavior of people, i.e. latent periods of 24 hours or 7 days, correspond to peaks in the number of individuals who are potentially at risk of becoming infected. The effect of this synchronization is present for a range of disease models with realistic parameters. The relationship between the latent period of an infectious disease and its pervasiveness is non-linear and depends strongly on the social context in which the disease is spreading.