Overview

Contact tracing works by identifying people who were recently exposed to SARS-CoV-2. Bluetooth signals can be used to detect when two devices, e.g. two smartphones, were close to each other.

• Amanda Wilson will briefly summarize current knowledge about how SARS-CoV-2 is transmitted, i.e. ballistic droplets vs. short-range aerosol vs. long-range aerosol vs. fomites. She will then present an approach inspired by quantitative microbial risk assessment (QMRA) to estimate how great a risk of infection from short-range aerosol transmission is predicted by contact at a given timing relative to symptom onset (given variable infectiousness), duration (given that dose increases with the length of exposure), and distance (as best as can be captured by Bluetooth).
  
  
• Curran Schiefelbein will present more elaborate experiments on Bluetooth performance, using robots to simulate a range of scenarios.
  
  
• Ramsey Faragher will discuss the potential for Bluetooth and other technologies such as ultra-wideband (UWB) and ultrasound to provide more and more reliable information, both about proximity and about indoor vs. outdoor status. These currently involve working outside the limitations of the current Google Apple Exposure Notification protocol, but can still be done in a decentralized, privacy-preserving manner.