Contact Tracing

Record and trace exposure to other people that may have been sufficient to transmit the virus

Contact tracing for Vietnam

Contact tracing for Germany


For implementation alternatives, see Contact tracing.


A variety of limitations to technical approaches to contact tracing (e.g. via wireless networking) are known, including:

  • Bluetooth distance measurements via RSSI are notoriously unreliable, particularly in urban environments with many materials (like steel) that dampen and reflect radio waves.
  • The likelihood of transmission of the disease is not directly measured by distance and duration of exposure to an infected individual. For example, there are big differences whether the encounter is indoors, or outdoors in strong winds.
  • It is often impossible to distinguish between close encounters in open space and those with a wall or floor between people: the distance may be the same, but wireless network cannot tell about the wall or floor.

Does it work?