there were 879,865 positive cases that were eligible for follow-up, of which 817,335 (92.9%) were reached and asked to provide details of their recent contacts
o blith y 879,865 o achosion positif a oedd yn gymwys i gael camau dilynol, cafwyd gafael ar 817,335 (92.9%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar