of the 723,597 positive cases that were eligible for follow-up, 670,981 (92.7%) were reached and asked to provide details of their recent contacts
o blith y 723,597 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 670,981 (92.7%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar