of the 30,823 positive cases that were eligible for follow-up, 26,863 (87.2%) were reached and asked to provide details of their recent contacts
o blith y 30,823 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 26,863 (87.2%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar