Assessing the effectiveness of test-trace-isolate interventions using a multi-layered temporal network
Journal:
arXiv
Published Date:
Dec 18, 2024
Abstract
In the early stage of an infectious disease outbreak, public health
strategies tend to gravitate towards non-pharmaceutical interventions (NPIs)
given the time required to develop targeted treatments and vaccines. One of the
most common NPIs is Test-Trace-Isolate (TTI). One of the factors determining
the effectiveness of TTI is the ability to identify contacts of infected
individuals. In this study, we propose a multi-layer temporal contact network
to model transmission dynamics and assess the impact of different TTI
implementations, using SARS-CoV-2 as a case study. The model was used to
evaluate TTI effectiveness both in containing an outbreak and mitigating the
impact of an epidemic. We estimated that a TTI strategy based on home isolation
and testing of both primary and secondary contacts can contain outbreaks only
when the reproduction number is up to 1.3, at which the epidemic prevention
potential is 88.2% (95% CI: 87.9%-88.5%). On the other hand, for higher value
of the reproduction number, TTI is estimated to noticeably mitigate disease
burden but at high social costs (e.g., over a month in isolation/quarantine per
person for reproduction numbers of 1.7 or higher). We estimated that strategies
considering quarantine of contacts have a larger epidemic prevention potential
than strategies that either avoid tracing contacts or require contacts to be
tested before isolation. Combining TTI with other social distancing measures
can improve the likelihood of successfully containing an outbreak but the
estimated epidemic prevention potential remains lower than 50% for reproduction
numbers higher than 2.1.
