Singapore is employing contract trackers to work out exactly who coronavirus patients have and haven't come into contact with in the period leading up to their diagnosis.

They research cases through interviews with the patient and examining of (digital) calendars and receipts, to piece together a picture of exactly who each patient has interacted with, where, and when, before reporting back to the Singaporean Ministry of Health.

Transmission of coronavirus is easy and done through person-to-person contact. This solution is to create a new job attached to the Ministry of Health, to generate the information of exactly who people have and haven't been in contact with in the buildup to their diagnosis, to hopefully work out other patients who else may have had the virus.

Singapore Ministry of Health