Contact tracing is the process of reconstructing the interactions of a sick person from the time they were infected until the time they were diagnosed. A case investigator reaches out to a person who has tested positive and helps them create a list of contacts they've recently been close to, who may have been exposed. Their contacts are then notified about their potential exposure and are given recommendations to help slow down the spread of the virus.
Contact tracing has typically been done manually. Manual contact tracing is a proven method and is highly effective. However, it requires a lot of time and resources. New tools can help scale and supplement manual contact tracing, such as digital contact tracing and exposure notification technology, like Covid Watch.