there were 4,279 positive cases eligible for follow-up, of which 3,808 (89.0%) were reached and asked to provide details of their close contacts*
o blith y 4,279 o achosion positif a oedd yn gymwys i gael camau dilynol, cafwyd gafael ar 3,808 (89.0%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar*