of the 918 positive cases that were eligible for follow-up, 813 (89%) were reached and asked to provide details of their recent contacts.
o blith y 918 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 813 (89%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar