of the 23,830 positive cases that were eligible for follow-up, 22,358 (94%) were reached and asked to provide details of their recent contacts
o blith y 23,830 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 22,358 (94%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar