of the 16,173 positive cases that were eligible for follow-up, 14,709 (90.9%) were reached and asked to provide details of their recent contacts
o blith y 16,173 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 14,709 (90.9%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar