Of the 334 positive cases that were eligible for follow-up, 270 (81%) were reached and asked to provide details of their recent contacts.
O blith y 334 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 270 (81%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar.