of the 18,128 positive cases that were eligible for follow-up, 14,966 (83%) were reached and asked to provide details of their recent contacts
o blith y 18,128 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 14,966 (83%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar