of the 15,719 positive cases that were eligible for follow-up, 12,218 (77.7%) were reached and asked to provide details of their recent contacts
o blith y 15,719 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 12,218 (77.7%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar