of the 636,505 positive cases that were eligible for follow-up, 589,195 (92.6%) were reached and asked to provide details of their recent contacts
o blith y 636,505 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 589,195 (92.6%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar