of the 529,486 positive cases that were eligible for follow-up, 498,944 (94.2%) were reached and asked to provide details of their recent contacts
o blith y 529,486 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 498,944 (94.2%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar