Engagement and adherence trade-offs for SARS-CoV-2 contact tracing. (31st May 2021)

• Record Type: Journal Article
• Authors: Lucas, Tim C. D.; Davis, Emma L.; Ayabina, Diepreye; Borlase, Anna; Crellen, Thomas; Pi, Li; Medley, Graham F.; Yardley, Lucy; Klepac, Petra; Gog, Julia; Déirdre Hollingsworth, T.
• Is Part Of: Philosophical transactions. Volume 376:Number 1829(2021)
• Publication Date: 2021-05-31
• Subjects: COVID-19 -- contact tracing -- SARS-CoV-2 -- adherence -- case isolation -- quarantine; Biology -- Periodicals; Science -- Periodicals; 570
• DOI: 10.1098/rstb.2020.0270
• Languages: English
• ISSNs: 0962-8436

Abstract

Abstract : Contact tracing is an important tool for allowing countries to ease lockdown policies introduced to combat SARS-CoV-2. For contact tracing to be effective, those with symptoms must self-report themselves while their contacts must self-isolate when asked. However, policies such as legal enforcement of self-isolation can create trade-offs by dissuading individuals from self-reporting. We use an existing branching process model to examine which aspects of contact tracing adherence should be prioritized. We consider an inverse relationship between self-isolation adherence and self-reporting engagement, assuming that increasingly strict self-isolation policies will result in fewer individuals self-reporting to the programme. We find that policies which increase the average duration of self-isolation, or that increase the probability that people self-isolate at all, at the expense of reduced self-reporting rate, will not decrease the risk of a large outbreak and may increase the risk, depending on the strength of the trade-off. These results suggest that policies to increase self-isolation adherence should be implemented carefully. Policies that increase self-isolation adherence at the cost of self-reporting rates should be avoided. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'.