O 1 Mehefin, byddwn yn rhoi'r broses o olrhain cysylltiadau'r boblogaeth ar waith ar gyfer pobl ar ôl iddynt gael canlyniad prawf positif.  O ystyried natur symptomau'r coronafeirws, bydd y mwyafrif llethol o bobl sy'n meddwl bod ganddynt symptomau ac yn cael eu profi yn cael canlyniad negatif. Ar hyn o bryd, dim ond 12% o brofion sy'n arwain at ganlyniad positif. Wedi hynny, gallai proses o olrhain cysylltiadau a gaiff ei hysgogi gan gyswllt ag unigolyn sydd â symptomau (h.y. rhywun sydd wedi gofyn am gael prawf) olygu y bydd gofyn i lawer o bobl hunanynysu pan nad oes achos positif.
From 1 June, we will implement population contact tracing on receipt of a positive test result. Given the nature of coronavirus symptoms, the vast majority of people who think they are symptomatic and seek a test return a negative result. At present on average only 12% of tests are returning a positive result. Consequently contact tracing initiated by contact with a symptomatic individual (i.e. someone who has sought a test) could result in many people being asked to isolate when there is no positive case.