of the 853,151 positive cases that were eligible for follow-up, 791,863 (92.8%) were reached and asked to provide details of their recent contacts
o blith y 853,151 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 791,863 (92.8%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar