of the 6,351 positive cases that were eligible for follow-up, 5,718 (90%) were reached and asked to provide details of their recent contacts
o blith y 6,351 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 5,718 (90%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar