of the 289,615 positive cases that were eligible for follow-up, 280,373 (96.8%) were reached and asked to provide details of their recent contacts
o blith y 289,615 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 280,373 (96.8%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar