4 ms·

Immediate reaction: I'm sorry they settled on blue-tooth induced proximity. It seems likely to be a poor approximation of "epidemiologically relevant proximity"

Immediate reaction: I'm sorry they settled on blue-tooth induced proximity. It seems likely to be a poor approximation of "epidemiologically relevant proximity". I would like to see research supporting the efficacy of this approach. I suspect they would conclude they need a geolocation-based approach. This will make privacy even more difficult.

adrianN 7y ago
If you're in "epidemiologically relevant proximity" you're almost surely also in bluetooth proximity. Quarantining a few more people than necessary is not a big deal and totally worth the privacy tradeoff imho.
- obituary_latte 7y ago
  I wonder if there would be a way to do something like this but using WiFi access points that are available. The phone could track access points as they come into range (don’t need to connect) and time stamps and cross correlate with others. Seems a bit less intrusive and wouldn’t require Bluetooth but obviously there wouldn’t be as much coverage.
  - lun4r 7y ago
    sharing a timeline of access points and timestamps is somewhat similar to a timeline of gps coordinates and timestamps. there is a lot to infer from such data and can potentially reveal the identity of the person who got sick and shared their data
- okintheory 7y ago
  Is that true? I'm more worried about false negatives on connections. Two concerns (as a layperson): 1) Transmission via surfaces is thought to be important (afaik). You don't have to be in the same place at the same time to transmit. 2) My bluetooth seems pretty slow and unreliable when connecting to my headphones. Is it reliable for logging ~50 proximities during my trip to the supermarket?
  - zby 7y ago
    Ad. 2 - it is not that bad: duration of proximity is correlated with both infection probability and connection probability.
  - arghwhat 7y ago
    1) That would be difficult to solve. If we used position reporting, and considered an area infected for a few days after an infected person arrived, it would most likely lead to unmanageable amounts of false positives. 2) Scanning is mostly just listening and waiting for other devices to send beacons. With one discoverable device nearby, it might take a moment to hear anything. With 50 devices nearby, you scan should be spammed with results. You might have missed a few devices if you were unlucky and moved out of range before they got a successful beacon through. However, in that case you could use second-hand proximity to find the "lost" contact through some of the successful ones.
  - HSO 7y ago
    > 1) Transmission via surfaces is thought to be important (afaik). According to Hendrik Streeck, a leading researcher in Germany, this may not be the case: https://youtu.be/VP7La2bkOMo?t=231 https://youtu.be/VP7La2bkOMo?t=231 They are working on a more formal study of this but indications are that the viruses that other teams have found on surfaces may be "dead" (in the sense that they cannot actually replicate anymore and therefore are not bioactive relatively soon after leaving host organisms). Video only in German, sorry, sure this will get publicized internationally if the study confirms the indications.
    - xenonite 7y ago
      as you say it _may_ not be the case. So, as long as no one knows for sure...
      - deleted 7y ago
        [deleted]
    - xenonite 7y ago
      This totally contradicts another study [1]. They found that the virus is "viable and infectious in aerosols for hours and on surfaces up to days (depending on the inoculum shed)." [1] https://www.nejm.org/doi/10.1056/NEJMc2004973 https://www.nejm.org/doi/10.1056/NEJMc2004973
divbzero 7y ago
The proximity tracing does not have to be perfect, just like social distancing or face masks do not have to be perfect. They just need to be effective enough to reduce R < 1.

adrianN 7y ago

If you're in "epidemiologically relevant proximity" you're almost surely also in bluetooth proximity. Quarantining a few more people than necessary is not a big deal and totally worth the privacy tradeoff imho.

obituary_latte 7y ago
I wonder if there would be a way to do something like this but using WiFi access points that are available. The phone could track access points as they come into range (don’t need to connect) and time stamps and cross correlate with others. Seems a bit less intrusive and wouldn’t require Bluetooth but obviously there wouldn’t be as much coverage.
- lun4r 7y ago
  sharing a timeline of access points and timestamps is somewhat similar to a timeline of gps coordinates and timestamps. there is a lot to infer from such data and can potentially reveal the identity of the person who got sick and shared their data
okintheory 7y ago
Is that true? I'm more worried about false negatives on connections. Two concerns (as a layperson): 1) Transmission via surfaces is thought to be important (afaik). You don't have to be in the same place at the same time to transmit. 2) My bluetooth seems pretty slow and unreliable when connecting to my headphones. Is it reliable for logging ~50 proximities during my trip to the supermarket?
- zby 7y ago
  Ad. 2 - it is not that bad: duration of proximity is correlated with both infection probability and connection probability.
- arghwhat 7y ago
  1) That would be difficult to solve. If we used position reporting, and considered an area infected for a few days after an infected person arrived, it would most likely lead to unmanageable amounts of false positives. 2) Scanning is mostly just listening and waiting for other devices to send beacons. With one discoverable device nearby, it might take a moment to hear anything. With 50 devices nearby, you scan should be spammed with results. You might have missed a few devices if you were unlucky and moved out of range before they got a successful beacon through. However, in that case you could use second-hand proximity to find the "lost" contact through some of the successful ones.
- HSO 7y ago
  > 1) Transmission via surfaces is thought to be important (afaik). According to Hendrik Streeck, a leading researcher in Germany, this may not be the case: https://youtu.be/VP7La2bkOMo?t=231 https://youtu.be/VP7La2bkOMo?t=231 They are working on a more formal study of this but indications are that the viruses that other teams have found on surfaces may be "dead" (in the sense that they cannot actually replicate anymore and therefore are not bioactive relatively soon after leaving host organisms). Video only in German, sorry, sure this will get publicized internationally if the study confirms the indications.
  - xenonite 7y ago
    as you say it _may_ not be the case. So, as long as no one knows for sure...
    - deleted 7y ago
      [deleted]
  - xenonite 7y ago
    This totally contradicts another study [1]. They found that the virus is "viable and infectious in aerosols for hours and on surfaces up to days (depending on the inoculum shed)." [1] https://www.nejm.org/doi/10.1056/NEJMc2004973 https://www.nejm.org/doi/10.1056/NEJMc2004973

divbzero 7y ago

The proximity tracing does not have to be perfect, just like social distancing or face masks do not have to be perfect. They just need to be effective enough to reduce R < 1.