It would therefore be valuable to test in selected care homes that have not reported an outbreak, so that we can understand the prevalence of these cases.
Felly, byddai'n werthfawr profi mewn cartrefi gofal dethol nad ydynt wedi rhoi gwybod am achosion, fel y gallwn ddeall pa mor gyffredin yw'r achosion hyn.