Read about OpenEMR's Response to the COVID-19 Pandemic at https://www.open-emr.org/covid19/

A separate app a C19-tracking-system

If a citizen is found positive for the covid-19 virus, he / she can report the public places where he has been (bars restourans, disco, gov.office) also trains or planes taken in the last 48 hours, the data can be displayed in a map.

Should be a separate application/repository.
Should be reusable (1 installation for country or state)