People Count: Contract-Tracing Apps and Public Health

Professor Susan Landau offers an introduction to the technology of contact tracing and its usefulness for public health, considering questions of efficacy, equity, and privacy.
People Count

Susan Landau is bridge professor in cybersecurity and policy, and splits her time between Fletcher and Tufts University's School of Engineering (as a professor of Computer Science). She is the director of the MS in cybersecurity and public policy and works at the intersection of cybersecurity, national security, law, and policy.

What questions does your research address?

With COVID-19, we have faced a medical crisis but also a social one, with the disease making clear the deep inequities within society. The coronavirus spreads when people are in close proximity, especially indoors. Containing the spread of the disease is particularly difficult given that people are infectious prior to being symptomatic (and some people are infectious but remain asymptomatic). Digital tools, especially smartphones, are potential tools for determining exposure and thus enabling people to isolate when they may be infectious. How do they work?—and are they effective.

In this book, Professor Susan Landau discuss how manual contact tracing works, what is most effective, and how digital tools determine proximity. She discusses the privacy concerns of using digital-proximity checking tools. A 1993 National Academies study on the social impact of AIDS observed that “An epidemic is both a medical and social occurrence.” Professor Landau discuss the equity issues raised by using digital proximity-checking tools, and what policy rules should guide their use for protecting us all.

What are the primary findings?

With a disease that spreads as COVID-19 does through respiratory droplets between people, often before people are showing symptoms, it is tempting to turn to digital tools to inform people of exposure. Use of such tools raises important questions about privacy but also equity. This is not the last pandemic we will face. The next one will undoubtedly be different, but we need now to be making choices about the social and medical interventions we make. This book is intended to lay out the impact of those choices, enabling us to make sensible, ethical, and healthy ones for our society and the people in it.