PACT Technical Reports
Summary: This paper describes the PACT (Private Automated Contact Tracing) protocol, a simple, decentralized approach to using smartphones for contact tracing based on Bluetooth proximity.
Download the Paper Here: https://pact.mit.edu/wp-content/uploads/2020/11/The-PACT-protocol-specification-2020.pdf
Abstract: “The process of contact tracing to reduce the spread of highly infectious and life-threatening diseases has traditionally been a primarily manual process managed by public health entities. This process becomes challenged when faced with a pandemic of the proportions of SARS-CoV2. Digital contact tracing has been proposed as way to augment manual contact tracing and lends itself to widely proliferated devices such as cell phones and wearables. This paper describes a method and analysis of determining whether two cell phones, carried by humans, were in persistent contact of no more than 6 feet over 15 minutes using Bluetooth Low Energy signals. The paper describes the approach to detecting these signals, as well as a data-driven performance analysis showing that larger numbers of samples with more optimal detection algorithms, coupled with privacy preserving auxiliary information, improves detection performance.”
Download the Paper Here: https://pact.mit.edu/wp-content/uploads/2020/11/TCFTL_paper_FINAL_V15_w_logos.pdf
Summary: “Throughout the course of the COVID-19 pandemic, several countries have developed and released contact tracing and exposure notification smartphone applications (apps) to help slow the spread of the disease. To support such apps, Apple and Google have released Exposure Notification Application Programming Interfaces (APIs) to infer device (user) proximity using Bluetooth Low Energy (BLE) beacons. The Private Automated Contact Tracing (PACT) team has shown that accurately estimating the distance between devices using only BLE radio signals is challenging . This paper describes the design and implementation of the SonicPACT protocol to use near-ultrasonic signals on commodity iOS and Android smartphones to estimate distances using timeof- flight measurements. The protocol allows Android and iOS devices to inter-operate, augmenting and improving the current exposure notification APIs. Our initial experimental results are promising, suggesting that SonicPACT should be considered for implementation by Apple and Google.”
Download the Paper Here: https://pact.mit.edu/wp-content/uploads/2020/11/SonicPACT_Final_v2-with-logos-revA.pdf
Ted Londner, Jonathan Saunders, Dieter W. Schuldt, Dr. Bill Streilein
“Speed is critical to the success of a response to an epidemic. During an uncontrolled outbreak the number of cases grows exponentially, so removing infected individuals from the population will have tremendous payoffs in terms of reducing the overall number of infections.
Mitigation strategies that remove infectious individuals from the greater population have to balance their efficacy with the economic effects associated with quarantine and have to contend with the limited resources available to the public health authorities. Prior strategies have relied on testing and contact tracing to find individuals before they become infectious and in order to limit their interactions with others until after their infectious period has passed.
Manual contact tracing (MCT) is a public health intervention where individuals testing positive are interviewed to identify other members of the community who they may have come into contact with. These interviews can take a significant amount of time that has to be tallied in the overall accounting of the outbreak cost.
The concept of contact tracing has been expanded recently into “Automatic Electronic Notification” (AEN) or “Electronic Contact Tracing” whereby individual’s cellphones can be used as sensor platforms to log close contacts and notify them in the event that one of their close contacts tests positive. The intention is that this notification will prompt the person to be tested and then restrict their interactions with others until their status is determined.
In this paper we describe our efforts to investigate the effectiveness of contact tracing interventions on controlling an outbreak. This is accomplished by creating a model of disease spread and then observing the impact that simulated tracing and testing have on the number of infected individuals. Model parameters are explored to identify critical transition points where interventions become effective. We estimate the benefits as well as costs in order to offer insight to public health officials as they select courses of action.”
Download the Paper Here: https://pact.mit.edu/simulated-automatic-exposure-notification-simaen-exploring-the-effects-of-interventions-on-the-spread-of-covid-wlogos/
Jesslyn Alekseyev, Erica Dixon, Vilhelm L Andersen Woltz, and Danny Weitzner
“This whitepaper is intended to provide usable information for States who are considering the deployment of an AEN system, as well as to guide ongoing improvements for States that have already deployed. We outline the human factors considerations related to employing AEN systems with the ultimate goal of controlling the spread of COVID-19, including the GAEN consortium Exposure Notifications (EN) Express tool. We will also provide a practical design and implementation guide for States and others designing and deploying AEN systems, as well as a set of recommendations for assessing deployment of contact tracing apps and targeting areas of concern to improve efficacy of use during and after initial deployment. As a case study, we consider the commercial app deployed by the state of Pennsylvania (PA) and the ongoing efforts to drive user adoption there.”
Download the Paper Here: https://pact.mit.edu/wp-content/uploads/2021/03/2020-10-29_AEN-Human-Factors-Final.pdf
Description: Sides about the PACT project presented by Marc Zissman at the NIH Webinar on Exposure Notification Digital Tools, 1 March 2021
Description: Sides about the PACT project presented by Marc Zissman at NIST Workshop on Challenges for Digital Proximity Detection in Pandemics: Privacy, Accuracy, and Impact.
Download the Slides: https://pact.mit.edu/wp-content/uploads/2021/01/2021-01-26-Zissman-AEN-Tutorial-for-NIST-workshop-v8b-with-no-videos.pdf
Description: Sides about the PACT project presented by Marc Zissman at the IEEE UK and Ireland Christmas Lecture 2020.
Description: Sides about the PACT project presented by Marc Zissman at a Keynote Presentation at the EEE Consumer Technology Society 10th IEEE International Conference on Consumer Electronics – ICCE Berlin 2020.
Download the Slides: https://pact.mit.edu/wp-content/uploads/2020/11/2020-11-09-Zissman-IEEE-Consumer-Electronics-v7c.pdf
Description: Sides about the PACT project presented by Marc Zissman at the IEEE EMBS 2020 Annual Conference.
Download the Slides: https://pact.mit.edu/wp-content/uploads/2020/07/Zissman-PACT-Talk-for-IEEE-EMBS-2020.pdf
Louise C Ivers & Daniel J Weitzner.
Abstract: “Contact tracing is a fundamental public health intervention, and a mainstay in efforts to control and contain severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the COVID-19 pandemic. At the time of writing, the pandemic has caused more than 13 million cases and more than 578000 deaths.1 Regions with the most successful containment to date have approached the pandemic with integrated measures that include cohesive leadership, effective communication, physical distancing, wearing of face coverings, improvements in the built environment, promotion of hand hygiene, and support for the staff, supplies, and systems needed to care for patients—with testing and contact tracing as cornerstones of the approach. Despite the emergence of some promising therapies2 and work towards a future vaccine,3 basic public health approaches remain the best available prevention and control interventions at this time.”
Download the Paper Here: https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(20)30160-2/fulltext
Abstract: “Contact investigations have been a vital public health strategy, most recently in controlling tuberculosis and sexually transmitted infections including HIV. Yet, the sheer scale of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections poses major challenges to contact investigations. Strategies in China, Singapore, South Korea, and Taiwan have supplemented traditional manual approaches with digital surveillance through smartphone applications.
The US has not used digital surveillance as a tool, but Google, Apple, the Massachusetts Institute of Technology (MIT), as well as 2 pan-European consortia and a variety of independent efforts are developing Bluetooth smartphone technology to enable rapid notification of users that they have had a close exposure to individuals diagnosed with medically verified coronavirus disease 2019 (COVID-19). How does digital tracking differ from manual tracing? Although digital surveillance has the distinct advantages of scale and speed, does it confer sufficient public health benefit to justify adoption given privacy concerns? How do the design choices of digital contact tracing systems affect public health and privacy?”Download the Paper Here: https://jamanetwork.com/journals/jama/fullarticle/2766675