of the 15,444 positive cases that were eligible for follow-up, 13,568 (88%) were reached and asked to provide details of their recent contacts
o blith y 15,444 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 13,568 (88%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar