Voluntary Data Rights scheme - we are not signed up to this yet AFAIK, but I hope we will
https://exposurealerting.org/
EU standards
https://edpb.europa.eu/sites/edpb/files/files/file1/edpb_guidelines_20200420_contact_tracing_covid_with_annex_en.pdf
Technical paper on how to protect privacy of infected user data. Hashing & PSI. Hashing may be a reasonable short-term solution, as it can still work with a simple server / flat text file.
https://arxiv.org/pdf/2003.14412v2.pdf
8 April Wired article discussing Safe Paths Privacy algorithms.
https://www.wired.com/story/covid-19-contact-tracing-apps-cryptography/